Arquivo da tag: Clima

Global climate models do not easily downscale for regional predictions (Science Daily)

Date:
August 24, 2016
Source:
Penn State
Summary:
One size does not always fit all, especially when it comes to global climate models, according to climate researchers who caution users of climate model projections to take into account the increased uncertainties in assessing local climate scenarios.

One size does not always fit all, especially when it comes to global climate models, according to Penn State climate researchers.

“The impacts of climate change rightfully concern policy makers and stakeholders who need to make decisions about how to cope with a changing climate,” said Fuqing Zhang, professor of meteorology and director, Center for Advanced Data Assimilation and Predictability Techniques, Penn State. “They often rely upon climate model projections at regional and local scales in their decision making.”

Zhang and Michael Mann, Distinguished professor of atmospheric science and director, Earth System Science Center, were concerned that the direct use of climate model output at local or even regional scales could produce inaccurate information. They focused on two key climate variables, temperature and precipitation.

They found that projections of temperature changes with global climate models became increasingly uncertain at scales below roughly 600 horizontal miles, a distance equivalent to the combined widths of Pennsylvania, Ohio and Indiana. While climate models might provide useful information about the overall warming expected for, say, the Midwest, predicting the difference between the warming of Indianapolis and Pittsburgh might prove futile.

Regional changes in precipitation were even more challenging to predict, with estimates becoming highly uncertain at scales below roughly 1200 miles, equivalent to the combined width of all the states from the Atlantic Ocean through New Jersey across Nebraska. The difference between changing rainfall totals in Philadelphia and Omaha due to global warming, for example, would be difficult to assess. The researchers report the results of their study in the August issue of Advances in Atmospheric Sciences.

“Policy makers and stakeholders use information from these models to inform their decisions,” said Mann. “It is crucial they understand the limitation in the information the model projections can provide at local scales.”

Climate models provide useful predictions of the overall warming of the globe and the largest-scale shifts in patterns of rainfall and drought, but are considerably more hard pressed to predict, for example, whether New York City will become wetter or drier, or to deal with the effects of mountain ranges like the Rocky Mountains on regional weather patterns.

“Climate models can meaningfully project the overall global increase in warmth, rises in sea level and very large-scale changes in rainfall patterns,” said Zhang. “But they are uncertain about the potential significant ramifications on society in any specific location.”

The researchers believe that further research may lead to a reduction in the uncertainties. They caution users of climate model projections to take into account the increased uncertainties in assessing local climate scenarios.

“Uncertainty is hardly a reason for inaction,” said Mann. “Moreover, uncertainty can cut both ways, and we must be cognizant of the possibility that impacts in many regions could be considerably greater and more costly than climate model projections suggest.”

Anúncios

Anthropologies #21: Weather changes people: stretching to encompass material sky dynamics in our ethnography (Savage Minds)

See original text here.

September 24, 2015.

This entry is part 10 of 10 in the Anthropologies #21 series.

Heid Jerstad brings our climate change issue to a close with this thoughtful essay. Jerstad (BA Oxford, MRes SOAS) is writing up her PhD on the effects of weather on peoples lives at the university of Edinburgh. Having done fieldwork in the western Indian Himalayas, she is particularly interested in the range of social and livelihood implications that weather (and thus climate change) has. She is on twitter @entanglednotion –R.A.

For most people, the climate change issue is a bundle of scientific ideas, or maybe a chunk of guilt lurking behind that short haul flight. The words have fused together to form a single stone, immobile and heavy. Change is a bit of a nothing word anyway – anything can change, and who is to say if it is good or bad, drastic or practically unnoticeable?

But what about climate? It is a big science-y word, neither human nor particularly tangible. Climate is about a place – engrained, palimpsested, with time-depth. That big sky, those habits – the Frenchman advising wine and bed on a rainy day, the Croatian judge lenient because there was a hot wind from the Sahara that day. This is weather I am talking about, seasons, years, the heat, damp and sparkling frost.

People care about the weather. We consider ourselves used to this or good at observing that. My home has more weather than other places – it is colder in winter, the air is clearer and brighter – because it is mine. My sunsets – this is eastern Norway – are vibrant and fill the sky, my sky will snow in June with not a cloud, my nose can feel that special tingle when it gets to below -20˚c. The north is not gloomy in winter – the snow is bright white, the hydro-fuelled streetlights illuminate empty streets and windows seal the warmth in.

What is your weather? It would be safe to assume it is part of the climate and I would go out on a limb and say I think you care about it. Am I wrong?

When the weather matters to people, the task becomes one of bridging this caring and the climate change science and projections. Looking at the impact of these weather changes in different areas of life is, then, going to make up a steadily larger part of useful climate change research.

Mead famously convened a conference with Kellogg titled ‘The Atmosphere: Endangered and Endangering’ in 1975, and Douglas published Risk and Blame in 1992. In the new millennium Strauss and Orlove (2003), Crate and Nuttall (2009) and Hastrup and Rubow (2014) brought edited volumes to the debate. It seems to be fairly well established, then, that climate change is a matter for anthropologists, as phrased by the AAA statement on climate change: ‘Climate change is rooted in social institutions and cultural habits. … Climate change is not a natural problem, it is a human problem.’ What then, can anthropologists do, about this problem?

Anthropologists provide description. The mapping of people’s stories of how the weather is ‘going wrong’, stories of change, and of coping and consequences is underway (Crate 2008 described the effects of unusual winter melt on the Vilui Sakha in Siberia, Cruikshank 2005 explored the tendrils of meaning surrounding glaciers between Alaska, British Colombia and the Yukon territory). Linked to the description, of course, and not really disentanglable from it is the explanation. Explanations and understandings of weather and weather changes in the places where they are happening, whether Chesapeake Bay, the Marshall Islands, or Rajasthan, India, fill in the social significance of what had been an empty sky (Paolisso 2003, Rudiak-Gould 2013, Grodzins-Gold 1998). The weather changes, in fact, constitute one of those satisfying areas of inquiry which concern those asked as much as the anthropologist.

The question of knowledge, however, can still seem a barrier when climate scientists are those with a mandate to understand changing weather. Anna Tsing, in the Firth Lecture at the Association of Social Anthropologists of the UK and Commonwealth’s (ASA) 2015 conference in Exeter, brought the contextual ecological study of mushrooms and the trees that they are mutual with in the forests of Japan and China to illustrate the gains anthropology can make when we give up scepticism of natural science. Earlier in the year, Moore, at the launch of the Centre of the Anthropology of Sustainability (CAOS) at University College London used microbial research to break down the bounded image of the body, where on the cellular level culture and biology shape each other – for instance when poor black women in the States eat fish which contains mercury and this affects the biological development of their children. Tsing and Moore brought together what might previously have been considered within the remit of ecology or biology to make important points about the capacity of anthropology—and to suggest where we might go next, expanding vision of social science. When mushrooms and microbes are appropriate topics for anthropological research, then looking at the climate and its material as well as social effects (rotting, drying, illness (Jerstad 2014)) starts to look feasible.

The anthropocene is a term which has been shown to have considerable analytical purchase outside of geology, illuminating moral and political debates about blame, the north-south divide and the global movement of materials, people and plants (Chakrabarty 2014, Tsing 2013). These ideas have been applyied in the study of climate scientists themselves (Simonetti 2015) as well as climate policy (Lahsen 2009). The anthropocene, i.e. the world as subject to the effects of human activities such as climate change, may be read as a set of material relationships, where the weather, bodies and landscapes meet, as Ingold showed (2010). This term allows the larger picture, where the world and all the people in it – those people for whom climate change matters – to be considered in a single conceptual space. In this space climate change can be seen as part of the encompassing extra-somatic human activity which defines our world as we are starting to understand it.

The anthropocene and climate change, however, both involve the challenge of how to follow the conceptual and material threads that lead from these global issues and into particular, ethnographically described lives:

 A close examination of scientific practice makes clear that localizing is as much a problem for climate researchers as it is for ethnographers. This holds not only for the     interconnectedness of the global and the local climate, but also for the separation of climate change as a ‘scientific fact’ on the one hand, and a ‘matter of concern’ on the other. Climate research offers an insight into a messy world of ramifications, surprising activities and unexpected “social” context (Krauss 2009:149–50).

Anthropological work has the reflexive capacity to deal with the messy world Krauss refers to here, where these ramifications, surprising activities and unexpected ‘social’ context are part of the particular places where we, as anthropologists, work, taking cues from events and observations around us. In my own fieldwork I found all kinds of unanticipated connections between weathers and other aspects of life. With a research proposal full of religion and ‘belief’ I ended up with far more material interests, guided by the sometimes patient and sometimes exasperated villagers with whom I lived in the western Indian Himalayas.

I was walking with Karishma to get green grass one day during the monsoon. She told me that our village (Gau) is famous for being misty, and therefore that the girls are known, both for working hard and for being beautiful, because even though they are outside the mistiness keeps them pale. So apparently on festival days people say that the girls from this village are gori (white) because there is so much mist here. But Karishma pointed out that this can’t be true because there is mist only in the rainy season. Then she said that the girls here wear sweaters to stay gori. Also, she said girls of this village have a reputation for being hard working so people ask for them in marriage when there is a household where work is to be done. This (I think) might be part of why quite a few of the new brides in Gau are not used to doing as much work as women do here. But then Karishma said fairly that it is not just the girls who work hard, everyone works hard in this village (well, most people). She said that when girls go away to study, like she did, then they come back more beautiful. That is to say pale from not being outside. She was saying how on the other hand I had become more black (kala) since being there in the village (this was true).

People, whether Himalayan villagers or Norwegian PhD students, live with weather on an ongoing basis, and consistently live in the weather, which is not always catastrophic but does always impinge (think food perishability, wardrobe choices, sitting in the shade). The considerations people have with regards to the weather, then, necessarily translate to potential climate change concerns. Climate change is a threat, it has potentially deadly dimensions, but weather is inherent to our world, and I would not want to pathologize it.

Weather relates in fundamental ways to sensation and the body, thermal infrastructure, agriculture and animal husbandry, health and illness, disasters and other areas of anthropology (that is to say life). Weather may be implicated in all kinds of ways with other areas of life – for instance the hot/cold symbolism in India which classifies illness, the body, food and even moods. I think that it can be surprisingly easy to forget or ignore weather precisely because it is so pervasive. And this resistance of the mind against focusing on it is a risk when it comes to climate change. It can be tiring to think about. How, after all, do you write about the wind? And people have (Parkin 1995, James 1972, Hsu and Low 2007), but personally I find it challenging just to make a start – capturing the sky with a few black marks on paper feels so unrealistic. In that sense it is a great stretching area for our minds, about the material and the social, about what we mean with words like ‘impact’ and ‘atmosphere’ and the connections between people and places.

Finally there is the role of anthropology in clarifying the terms of the climate change debate. This is a new kind of challenge, it is a global one (hence the usefulness of Tsing’s work, who demonstrated the crucial part material relationships and meetings play in globalisation (2005)), it is to do with both technologies and nature (we can apply Latour, who shows in ‘we have never been modern’ (1993) how ‘modernity’ has not succeeded in cutting us off from the material and natural world around us), it is political, historical (hence Chakrabarty, whose work pushes us to think in new ways about how we are positioned in history and what place climate change has in this context), and there is something about it which is pushing at the edges in all these areas and others, in which new terms are required to even conceive of some of these problematics. Building on what we understand and moving further, in ways that might tread new neural pathways and enable new realities, simply from the newness of our thinking, feels like a worthwhile undertaking. I suggest that the orientation of research which maps out the weather-weight of social life can help bring the people back into climate change.

So the immovable stone of ‘climate change’ is being loosened up, pulled apart to reassemble in illuminating and constructive ways by people contributing to blow away the fog obstructing understanding, using the culminations of what we know so far and the ways in which we can think new thoughts. This effort rewards.

References

AAA statement on climate change. 29th January 2015. http://www.aaanet.org/cmtes/commissions/CCTF/upload/AAA-Statement-on-Humanity-and-Climate-Change.pdf Accessed 1st July 2015.

Chakrabarty, Dipesh 2014. Climate and Capital: On Conjoined Histories. Critical Inquiry 41(1):1-23.

Crate, Susan. 2008. Gone the Bull of Winter? Grappling with the Cultural Implications of and Anthropology’s Role(s) in Global Climate Change. Current Anthropology 49:569-595.

Crate, Susan and Mark Nuttall, eds. 2009. Anthropology and Climate Change: from Encounters to Actions. California: Left Coast Press.

Cruikshank, Julie. 2005. Do Glaciers Listen? Local Knowledge, Colonial Encounters, and Social Imagination. Toronto: University of British Columbia Press.

Douglas, Mary. 1992. Risk and Blame. London: Routledge

Grodzins-Gold, Ann. 1998. Sin and Rain: Moral Ecology in Rural North India. In Lance Nelson ed. Purifying the Earthly Body of God. New York: State University of New York Press.

Hsu, Elizabeth and Chris Low eds. 2007: Wind, Life, Health: Anthropological and Historical Perspectives. Special issue. Journal of the Royal Anthropological Institute 13:S1-S181.

Ingold, T. (2010), Footprints through the weather-world: walking, breathing, knowing. Journal of the Royal Anthropological Institute, 16: S121–S139.

James, Wendy. 1972. The politics of rain control among the Uduk. In Ian Cunnison and Wendy James eds. Essays on Sudan ethnography presented to Sir Edward Evans-Pritchard. London: C. Hurst.

Jerstad, Heid. 2014. Damp bodies and smoky firewood: material weather and livelihood in rural Himachal Pradesh. Forum for development studies 41(3):399-414.

Krauss, Werner. 2009. Localizing Climate Change: A Multi-sited Approach. In Marc-Anthony Falzon and Clair Hall eds. Multi-Sited. Ethnography. Theory, Praxis and Locality in Contemporary Research 149-165. Ashgate.

Lahsen, Myanna. 2009. A science-policy interface in the Global South: The politics of carbon sinks and science in Brazil. Climatic Change 97:339–372.

Paolisso, Michael. 2003. Chesapeake Bay watermen, weather and blue crabs: cultural models and fishery policies. In Sarah Strauss and Benjamin Orlove eds. Weather, Climate, Culture. Oxford: Berg.

Rudiak-Gould, Peter. 2013. Climate change and tradition in a small island state: the rising tide. Routledge.

Simonetti, Christian. 2015. The stratification of time. Time and Society .

Strauss, Sarah and Orlove, Benjamin eds. 2003. Weather, climate, culture. Oxford: Berg

Tsing, Anna. 2013. Dancing the Mushroom Forest. PAN: Philosophy, Activism, Nature vol 10.

Tsing, Anna. 2005. Friction. Princeton University Press.

Brasil e mais 169 países assinam acordo sobre mudança climática (Estadão)

Cláudia Trevisan e Altamira Silva Junior – 22 de abril de 201

Dilma: 'O caminho que teremos de percorrer agora será ainda mais desafiador: transformar nossas ambiciosas aspirações em resultados concretos'

Dilma: ‘O caminho que teremos de percorrer agora será ainda mais desafiador: transformar nossas ambiciosas aspirações em resultados concretos’

Representantes de 170 países assinaram nesta sexta-feira, 22, o Acordo de Paris sobre mudança climática, batendo o recorde da história da Organização das Nações Unidas (ONU) de adesão a um tratado internacional em um único dia. Mas todos ouviram o alerta do secretário-geral da entidade, Ban Ki-Moon, de que as boas intenções terão pouco impacto se a convenção não for ratificada pelos países o mais breve possível. Sem isso, o tratado não entrará em vigor.

“Estamos em uma corrida contra o tempo”, disse Ban no discurso de abertura da cerimônia, no plenário da ONU em Nova York. A urgência foi enfatizada por vários chefes de Estado, incluindo os presidentes do Brasil, Dilma Rousseff, e da França, François Hollande.

Dilma assegurou “a pronta entrada em vigor” da convenção, mas essa decisão depende do Congresso. “O caminho que teremos de percorrer agora será ainda mais desafiador: transformar nossas ambiciosas aspirações em resultados concretos”, disse a presidente em seu discurso. E repetiu os compromissos assumidos pelo Brasil durante a negociação do tratado, entre os quais a promessa de reduzir em 37% a emissão de gases poluentes até 2025, na comparação com os patamares registrados em 2005.

Frustração. Carlos Rittl, secretário executivo do Observatório do Clima, disse que Dilma frustrou as expectativas de entidades ambientais que esperavam uma sinalização clara de que o Brasil assumirá metas mais ambiciosas em 2018, quando haverá uma avaliação dos resultados do acordo. “O Brasil precisa reconhecer que deve fazer mais que o prometido no ano passado”, disse. “Todos devem, porque estamos na trajetória de 3ºC de aquecimento.”

Aprovado por representantes de 195 nações em dezembro, o tratado prevê uma série de compromissos nacionais com o objetivo de limitar o aumento da temperatura do planeta a 2ºC até o fim do século, em relação ao patamar anterior ao período industrial. Para que entre em vigor, o Acordo de Paris precisa ser ratificado por pelo menos 55 países que representem ao menos 55% das emissões de gases do efeito estufa.

“A era do consumo sem consequências chegou ao fim. Nós temos de intensificar os esforços para ‘descarbonizar’ nossas economias”, ressaltou o secretário-geral das Nações Unidas. Além do caráter simbólico, a cerimônia desta sexta tinha o objetivo de mobilizar os líderes mundiais em torno da ratificação do acordo, de forma que entre em vigor no próximo ano e não em 2020, como inicialmente previsto.

Primeiro a discursar, o presidente da França lembrou que Paris vivia uma situação trágica em dezembro, sob o impacto dos atentados terroristas que haviam provocado a morte de 130 pessoas no mês anterior. Ainda assim, ressaltou, foi possível fechar o acordo histórico sobre mudança climática.

The Stark Realities of Baked-In Catastrophes (Collapse of Industrial Civilization)

02 Apr 2016

Joe-Webb-Greetings-From-California

In a civilization gone mad with delusions of grandeur, we’re left with tatters of human sociability held together by rancid mythologies.

Despite human fossil fuel burning recently reported to be “flat”, CO2 levels have been on a tear for the last six months, reaching new worrying levels which have some wondering whether permafrost melt may be contributing to the unusually high spike if no decline happens soon. The giant holes in Siberia serve as an ominous sign. Considering that the current El Niño is contributing only 10% to what we are now seeing, runaway global warming may be accelerating worldwide. But don’t worry, Warren Buffett says climate change is no more of a problem than the Y2K bug and will be profitable through increased premiums and inflation.

Ever dire studies continue to reaffirm worst case scenarios, making clear to anyone paying attention that Earth in the next century will be unrecognizable from its current state. Basic planetary geography and atmospheric conditions will be altered through warming oceans and rising sea levels which are now increasing faster than at any time in the past 2800 years. On average, sea levels were between 50 and 82 feet higher the last time CO2 levels were at 400ppm. Glaciologist Jason Box expects ice melt from the West Antarctic to become the biggest contributor to sea level rise in the coming decades due to a feedback loop not in the climate models. CO2 levels have been increasing around 3ppm per year, a twentyfold increase since pre-industrial times when the highest recorded increase was 0.15 ppm per year. We’ve long since passed the tipping point of melting Arctic summer sea ice; 300-350 ppm of CO2 was the threshold for many parts of the climate. These changes are irreversible on a timescale of human civilizations. Even if all human industrial activity magically ceased today, the footprint man has already left will be felt for eons.

In our warming world, the hydrologic cycle is changing and creating extreme weather; crop-destroying droughts and floods are becoming more frequent. The Jet Stream is transforming into something different, becoming wavier with higher ridges and troughs prone to stagnating in the same region. As global temperatures rise over time, hotter air will be trapped under these layers of high pressure from a mangled Jet Stream, cooking everything to death. Rising winter temperatures are beginning to destroy the “winter chill” needed for many fruit and nut trees to properly blossom and produce maximally. Climate change is also disrupting flower pollination and pushing fish toward North/South poles, robbing poorer countries at Equator of crucial food resources. In a new study, marine scientists are surprised to find a disturbing trend in the increasing numbers of a specific type of phytoplankton, coccolithophores, which have been “typically more abundant during Earth’s warm interglacial and high CO2 periods.”

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Homo sapiens have only been on the planet for the equivalent of a few seconds in geologic time but have managed to overwhelm and foul up all of earth’s natural processes and interdependencies, leaving a distinct layer in the sedimentary record. There is nothing modern humans do that is truly sustainable. Here are a few glaring examples:

No amount of reafforestation or growing of new trees will ultimately off-set continuing CO2 emissions due to environmental constraints on plant growth and the large amounts of remaining fossil fuel reserves,” Mackey says. “Unfortunately there is no option but to cut fossil fuel emissions deeply as about a third of the CO2 stays in the atmosphere for 2 to 20 millennia.

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Relying on machines for answers to the existential problems of a species run amok with planet-destroying tools and weaponry is rather ironic and tragic. We’re locked-up inside a complexity trap of our own making. The human propensity for tool-building coupled with our discovery of fossil fuels has created a set of living arrangements in which we are now enslaved to those machines and tools. The globalized capitalist economy externalizes its destruction and atrocities, keeping the masses in a state of ignorance and denial. Our corporate overlords are not conscientious citizens, but mindless organizations whose sole purpose is to grow profits no matter the external damage done to society and the environment. Between the economic oil hitmen who ensure that profits flow smoothly and GOP politicians who openly espouse their science illiteracy, a hospitable climate for future humans seems remote. Hopeful delusions have given way to the stark reality of our predicament as scholars like Noam Chomsky who originally started his career fighting for a modicum of social justice have now set the bar at just the chance of human survival. Despite the best efforts of scientists, environmentalists, and activists, the wealthy countries most able to do something won’t “get it” until famine, disease, and war come to their country. All is being left for the almighty ‘free market’ to sort out at the same time that climate change, a conflict multiplier, ramps up.

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The sixth mass extinction gathers steam and climate inertia works to catch up to the catastrophic ecological collapse already baked-in. All the while, modern man engages in the spectacle of tribal politics(building walls, exuding military strength, recapturing past glories of their nation) and presidential candidates discuss the size of their penis.

For those who come to understand modern man’s predicament, it can either be the ultimate mind fuck or an epiphany that helps a person appreciate the fragility of life, the urgency of living in the here and now, and the grand cosmic joke of a global, hi-tech civilization that arose from the burning of ancient fossil remains only to have those fumes become a deadly curse, extinguishing any trace of our lofty accomplishments…

The fossil record, Plotnick points out, is much more durable than any human record.

As humanity has evolved, our methods of recording information have become ever more ephemeral,” he said. “Clay tablets last longer than books. And who today can read an 8-inch floppy?” he shrugged. “If we put everything on electronic media, will those records exist in a million years? The fossils will.
– Link

Amid Climate-Fueled Food Crisis, Filipino Forces Open Fire on Starving Farmers (Common Dreams)

Published on Monday, April 04, 2016 by Common Dreams

Police and army forces in the Philippines unleashed bullets on a starving crowd, killing 10, for demonstrating for drought relief

by Nika Knight, staff writer

A wounded farmer is assisted by other demonstrators after Friday’s mass shooting by security forces in the Philippines. (Photo: Kilab Multimedia)

Police and army forces shot at about 6,000 starving farmers and Lumad Indigenous people demonstrating for drought relief in the Philippines on Friday, ultimately killing 10. Observers characterized the security forces’ action as “a strafing.”

“The government’s response to hunger is violence,” said Zeph Repollo, Southeast Asia campaign coordinator for 350.org, in an email to Common Dreams.

Three protesters were immediately killed, and by Monday the death toll had risen to 10 as more demonstrators succumbed to injuries.

“We don’t have anything to eat or harvest. Our plants wilted. Even our water has dried up.”
—Noralyn Laus, demonstrating farmer

The farmers and Indigenous people had been blockading a highway in the Cotabato province for four days in a desperate plea for government aid, after this winter’s record-breaking temperatures produced a three-months-long drought that has destroyed their crops and now threatens their lives.

The demonstrators were asking the government to provide 15,000 sacks of rice to ease the hunger crisis. Provincial governor Emmylou Mendoza has refused to engage the protesters.

“The government’s policy of  systematic land grabbing combined with the intensified El Nino pushed our farmers and indigenous peoples to heighten their struggles with sweat and blood in defense of their right to land and life,” wrote Repollo in a statement.

After an especially intense El Nino created a months-long drought and the local government ignored their plight, farmers and Indigenous people blockaded a highway to publicize their need for relief. (Photo: Pinoy Weekly)

After an especially intense El Nino created a months-long drought and the local government ignored their plight, farmers and Indigenous people blockaded a highway to publicize their need for relief. (Photo: Pinoy Weekly)

On Monday, local farmer Noralyn Laus gave Democracy Now! a firsthand account of the disaster:

“Why we came down here is not to make trouble. We just want to demand for rice, because of the situation of El Niño is leaving our tribes hungry. What happened yesterday, we didn’t start it. They started it by beating us. We wouldn’t be angry if we weren’t beaten up or attacked. We’re having a crisis. We don’t have anything to eat or harvest. Our plants wilted. Even our water has dried up.”

“Our farmers—the country’s food producers—are battered the hardest and are left in poverty and hunger,” Rapollo said. “Civil disobedience will continue to escalate until the government stops playing deaf and blind to the genuine cry of the people.”

Seventy-eight people were still under arrest on Monday, Rapollo said, and a local Methodist Church is sheltering many protesters who escaped the bullets. Rapollo also reported that no members of the armed forces have been relieved of duty or investigated for Friday’s shooting.

The state-sponsored violence in the Philippines portends what turmoil may come as the planet continues to warm, creating more disastrous, extreme weather events worldwide, environmental activists note.

“The conditions that prompted the 3-day blockade gives us a glimpse of what’s ahead if decisive and just actions in addressing climate change remain in the periphery,” said Repollo.

“This is not a distant reality to anywhere in the world,” Repollo wrote to Common Dreams, “unless we change the system that feeds [on] hunger, injustices, and climate catastrophe.”

Medidas de adaptação às mudanças climáticas são anunciadas em Santos (Pesquisa Fapesp)

04 de dezembro de 2015

Samuel Antenor, de Santos | Agência FAPESP – Um estudo internacional sobre a elevação do nível do mar causada pelas mudanças climáticas na cidade de Santos, litoral sul do Estado de São Paulo, resultou em um conjunto de propostas de adaptação, apresentado na terça-feira (01/12) na Associação Comercial de Santos.

No encontro, pesquisadores e representantes da sociedade civil, da Marinha e do Exército  discutiram propostas de ações a serem executadas na cidade nos próximos anos, a fim de enfrentar a elevação do nível do mar e suas consequências na maior cidade portuária do Brasil, ante a perspectiva de aumento da temperatura global acima de 2°C até o final deste século.

As sugestões apresentadas pelo grupo fazem parte da segunda etapa do Projeto Uma estrutura integrada para analisar tomada de decisão local e capacidade adaptativa para mudança ambiental de grande escala: estudos de caso de comunidades no Brasil, Reino Unido e Estados Unidos (Metropole, na sigla em inglês) que inclui pesquisas sobre a elevação da maré em outras duas cidades: Broward, nos Estados Unidos, e Selsey, na Inglaterra. Realizado por pesquisadores do Centro de Monitoramento de Desastres Naturais (Cemaden), do Instituto Nacional de Pesquisas Espaciais (Inpe), da Universidade de São Paulo (USP), da Universidade Estadual de Campinas (Unicamp) e do Instituto Geológico de São Paulo, o estudo, que contou com apoio de técnicos da Prefeitura Municipal de Santos, foi feito em parceria com pesquisadores da University of South Florida, dos Estados Unidos, e do King’s College London, da Inglaterra é apoiado pela FAPESP, no âmbito de um acordo de cooperação com o Belmont Forum.

Santos foi escolhida não apenas por suas características geográficas e importância estratégica para o Brasil, mas por reunir os mais completos dados sobre elevação de marés no país, registrados desde 1945 por marégrafos e desde 1993 também por satélite (para saber mais sobre o projeto Metropole leia agencia.fapesp.br/21997/).

“Foi elaborada uma estimativa de tendências de nível médio do mar, com dados de marégrafo e de topografia dinâmica por altimetria de satélites, considerando a confiabilidade, estabilidade e consistência desses dados”, explicou Luci Hidalgo Nunes, pesquisadora da Unicamp e participante do projeto.

Os dados coletados pelos pesquisadores foram inseridos na plataforma COAST (Coastal Adaptation to Sea Level Rise Tool), desenvolvida por uma empresa norte-americana, que ficou também responsável pelo armazenamento dos dados provenientes das três cidades integrantes do Projeto Metropole.

No caso de Santos, além dos dados espaciais georreferenciados e das variáveis relacionadas à elevação do nível do mar, foram consideradas variáveis socioeconômicas.

A partir disso, foram traçados dois níveis de impacto nas regiões sudeste e noroeste da cidade, englobando diferentes áreas do município, em um total de 13 km², onde vivem 117 mil pessoas, e cujas previsões de elevação do nível do mar ficam entre 18 cm e 23 cm em 2050, com projeções de 36 cm a 45 cm até 2100.

Medidas adaptativas

Considerando os cenários atuais, os dados indicam que o regime de chuvas e as ressacas na região de Santos tenderão a ser mais intensos e mais frequentes nas próximas décadas. Isso decorre do aumento de temperatura global e da consequente elevação do nível do mar, além da possibilidade de eventos extremos.

Em Santos, as sugestões para diminuir as vulnerabilidades costeiras, apresentadas após avaliação de diferentes formas de adaptação, incluem obras de infraestrutura.

Além da preservação e recuperação de manguezais, foram sugeridas a implantação de comportas para controle de marés em rios, a construção de canais de drenagem, o aumento da faixa de areia na Ponta da Praia e a construção de quebra-mar na orla leste do município.

Para a zona noroeste do município, as propostas de medidas adaptativas incluem a dragagem de canais, a criação de um sistema de comportas e estações de bombeamento e a recuperação de mangues. Na região da Ponta da Praia, no sudeste santista, a recomendação é que sejam adotadas medidas para engordamento/alimentação artificial da praia, a construção de um muro de proteção e de um sistema de bombeamento e de melhoria de comporta de canais.

Para mensurar os custos da adoção ou não dessas propostas, foram avaliados dois cenários, com e sem as medidas adaptativas. Para chegar a um custo aproximado das adaptações, foram projetados cenários de perdas baseados exclusivamente no valor dos imóveis nas duas regiões. Custos relacionados a outras variáveis, como saúde e mobilidade, não foram computados.

Com projeções de elevação das marés em 45 cm até 2100, os danos chegariam a R$ 236 milhões na zona noroeste e passariam de R$ 1 bilhão na região sudeste do município, caso não sejam adotadas as medidas adaptativas. Com a adoção das medidas, os custos dos danos seriam nulos na orla e cairiam para R$ 64 milhões na região noroeste.

Os cálculos foram feitos com base em projetos internacionais e na tomada de preços para a execução de projetos feita pela própria administração municipal.

“Buscamos fornecer aos tomadores de decisão a melhor informação possível para o planejamento urbano futuro, quais seriam as ações indicadas e seus benefícios”, explicou José Marengo, pesquisador titular do Cemaden e coordenador do projeto no Brasil.

Políticas públicas

Uma das propostas do projeto é utilizar o conhecimento resultante dessas pesquisas para subsidiar medidas de enfrentamento de problemas advindos das mudanças climáticas e ajudar na tomada de decisões e na formulação de políticas públicas. Nesse sentido, a prefeitura de Santos publicou, também no dia 1º de dezembro, um decreto criando uma comissão municipal de adaptação à mudança do clima.

Entre outros pontos, o texto do decreto sugere a criação de estrutura organizacional, envolvendo o poder público, o setor produtivo e representantes da sociedade civil, para a execução das possíveis medidas a serem adotadas com base nas pesquisas.

“Não se deve esperar por uma catástrofe para usar o conhecimento científico sobre as mudanças climáticas para formular políticas públicas, mas agir de forma preventiva”, afirmou Roberto Greco, do Instituto de Geociências da Unicamp e membro do projeto.

Durante o encontro, foram discutidas diferentes formas de financiamento das propostas, além de ações para conscientizar e sensibilizar a população para a urgência do tema. Uma das tônicas da discussão foi justamente a necessidade de encontrar meios de garantir a participação popular na questão.

Os participantes do encontro reforçaram o caráter público e participativo das ações, que precisariam envolver toda a sociedade, permitindo a atuação pública por meio da representação social, incluindo pessoas físicas, no Conselho proposto em decreto pela atual gestão municipal.

“Santos é precursora neste nível de informação no Brasil, e o projeto só pode ser realizado com a ajuda da prefeitura no fornecimento das informações e apoio técnico para utilização dos dados. Seria impossível fazer um projeto como esse sem esse apoio”, afirmou Nunes.

De acordo com os pesquisadores, considerando não apenas a avaliação do nível do mar mas também aspectos relacionados aos ventos e ao clima, é a primeira vez que se faz um estudo desse tipo no Brasil, com uma clara proposta de subsidiar políticas públicas e a tomada de decisão.

A próxima fase da pesquisa será a elaboração de comparativos entre aspectos relacionados nas três cidades pesquisadas, a fim de trocar informações que reforcem o caráter de urgência das medidas de adaptação. 

Inundações costeiras em Santos podem causar prejuízos bilionários

07 de outubro de 2015

Elton Alisson, de Santos | Agência FAPESP – A inundação de áreas costeiras das zonas sudeste e noroeste de Santos, causada pela combinação da elevação do nível do mar com ressacas, marés meteorológicas e astronômicas e eventos climáticos extremos, pode causar prejuízos acumulados de quase R$ 2 bilhões até 2100 se não forem implementadas medidas de adaptação.

A estimativa é de um estudo internacional, realizado por pesquisadores do Centro de Monitoramento de Desastres Naturais (Cemaden), dos Institutos Nacional de Pesquisas Espaciais (Inpe) e Geológico (IG) e das Universidades de São Paulo (USP) e Estadual de Campinas (Unicamp), em parceria com colegas da University of South Florida, dos Estados Unidos, do King’s College London, da Inglaterra, além de técnicos da Prefeitura Municipal de Santos.

Os resultados do estudo, que fazem parte do projeto “Uma estrutura integrada para analisar tomada de decisão local e capacidade adaptativa para mudança ambiental de grande escala: estudos de casos de comunidades no Brasil, Reino Unido e Estados Unidos”, apoiado pela FAPESP, no âmbito de um acordo de cooperação com o Belmont Forum, foram apresentados na última quarta-feira (30/09) a representantes da sociedade civil de Santos.

Durante o encontro, os pesquisadores mostraram às lideranças locais projeções de elevação do nível do mar e de impactos econômicos até 2050 e 2100 nas regiões sudeste e noroeste de Santos – que já têm sido impactadas pelo aumento do nível do mar e atuação de eventos extremos – e discutiram possíveis medidas de adaptação para minimizar os riscos.

“Não é preciso esperar 20 ou 30 anos para sentir os efeitos da elevação do nível do mar. É possível implementar agora medidas de adaptação para minimizar os potenciais danos econômicos”, disse José Marengo, pesquisador titular do Cemaden e coordenador do projeto do lado do Brasil, à Agência FAPESP.

Os pesquisadores constataram por meio de dados sobre mudanças no nível do mar em Santos – obtidos por marégrafos na região no período entre 1945 e 1990 e por altimetria de satélite entre 1993 e 2013 –, que ele aumentou, em média, 3 milímetros nos últimos anos na cidade.

Com base nessa constatação, eles estimaram que o nível do mar na cidade pode aumentar entre 18 e 30 centímetros até 2050 e entre 36 centímetros e 1 metro em 2100.

A combinação dessa elevação  com uma sobrelevação causada por uma ressaca forte (ondas elevadas e maré meteorológica) e numa fase de maré de sigízia (maré astronômica de maior amplitude, que ocorre durante as luas cheia e nova, quando o Sol e a Lua estão alinhados em relação à Terra e há maior atração gravitacional), pode resultar em um rápido aumento do nível do mar em Santos de 90 centímetros até 2050 e 95 cm até 2100.

Nessas condições, as regiões sudeste e noroeste de Santos seriam ainda mais inundadas pelo mar e haveria maior erosão da praia.

“A planície costeira de Santos apresenta declividades muito baixas [menores de 2%] e altimetrias inferiores a 3 metros. Além disso, o nível do lençol freático da cidade é muito raso, o que a torna muito suscetível a inundações provocadas pelo mar e alagamentos devido às chuvas intensas”, explicou Joseph Harari, professor do Instituto de Oceanografia (IO) da USP e participante do projeto.

Aumento de ressacas

Os impactos relacionados com a elevação do nível do mar, combinada com marés meteorológicas e astronômicas e eventos meteorológicos, já estão sendo sentidos em Santos há algumas décadas.

Um estudo realizado por Celia Regina de Gouveia Souza, pesquisadora do Instituto Geológico e participante do projeto, constatou que o número de ressacas registradas na cidade teve um salto a partir do final da década de 1990.

Em 2010, por exemplo, foram registrados na cidade 15 eventos de ressaca, contra um número máximo de 4 por ano entre 1960 e início dos anos de 1990.

A pior ressaca do mar na cidade foi registrada em 2005 e levou a prefeitura municipal a colocar um anteparo de pedra no final da Ponta da Praia – região que tem sofrido com erosão costeira acelerada (perda de faixa de praia) desde o começo da década de 1940, com a construção da avenida à beira-mar sobre a praia.

A ressaca do mar, segundo a pesquisadora, está associada com o desenvolvimento de ciclones extratropicais, formados no sul da América do Sul e que avançam pela região Sudeste do Brasil, gerando ondas de alta energia e sobrelevação do nível do mar (maré meteorológica positiva), além de frentes frias que podem trazer muita chuva nas regiões costeiras.

“A intensidade dos impactos gerados na orla pela conjugação dessas condições com a elevação atual do nível do mar está aumentando, mas ainda não sabemos se a magnitude dos eventos tem se modificado”, afirmou Gouveia.

A região noroeste da cidade, por exemplo – onde estão concentrados imóveis cujo valor venal é, em geral, inferior aos da Ponta da Praia e onde vivem cerca de 83 mil pessoas –, sofre periodicamente com inundações, provocadas por marés positivas e de sizígia, além de enchentes.

Já a região sudeste – onde estão situados os imóveis de padrão mais elevado na cidade e onde vivem cerca de 34 mil habitantes – é afetada por alagamentos, causados por chuvas fortes, mas principalmente pela erosão costeira, que vem se agravando muito na Ponta da Praia.

“Essas duas regiões têm padrões diferentes de uso e ocupação do solo, que geram vulnerabilidades e, portanto, danos e perdas também diferentes em relação às projeções de elevação do nível do mar”, explicou Souza.

Cálculo de perdas

Os pesquisadores estimaram os possíveis danos econômicos de inundações costeiras nas zonas sudeste e noroeste de Santos, causadas pela elevação do nível do mar nos diferentes cenários projetados para 2050 e 2100, combinadas com uma sobrelevação da maré em 1,6 metros em 2050 e 1,66 metro em 2100, provocada por um evento extremo com ocorrência de uma vez a cada 100 anos.

Para isso, eles usaram um software de geoprocessamento chamado COAST (sigla de Coastal Adaptation to Sea Level Rise Tool), desenvolvido por uma empresa americana.

O software mensura os potenciais danos em ativos imobiliários provocados por inundação costeira a partir de dados da elevação do nível do mar, de marés astronômicas e meteorológicas e dados espaciais georreferenciados, cruzados com o valor venal do terreno (a soma do que foi gasto na construção do imóvel com o valor estimado do terreno), fornecidos pela prefeitura.

As projeções indicaram que a zona sudeste da cidade deverá ser a mais impactada nos três diferentes cenários de elevação do nível do mar projetados para 2050 e 2100.

Se não for adotada nenhuma medida de adaptação para uma elevação do nível do mar em um metro até 2100 – em um cenário mais extremo –, os danos econômicos podem ser de R$ 1,3 bilhão na região sudeste e de R$ 483,8 milhões na zona noroeste, estimam os pesquisadores.

“O COAST e outros modelos matemáticos ainda não são capazes de estimar a resiliência e a resistência dos ambientes, como por exemplo, como uma praia responde a uma elevação do nível do mar, ou como um manguezal consegue retardar o avanço do mar sobre áreas estuarinas”, afirmou Souza.

“De qualquer forma, é preciso estudar e adotar medidas de adaptação para minimizar os possíveis impactos socioeconômicos”, ponderou.

Algumas das medidas de adaptação que estão sendo adotadas no mundo para enfrentar as inundações e a erosão costeira causadas pelo aumento do nível do mar são barreiras naturais, como faixas de manguezais, implementadas em Palm Beach, na Flórida; engordamento de praia, como feito em Cuba e Miami; diques flutuantes, adotados em Veneza, na Itália; e readequações nos projetos de casas e prédios, para torná-los mais resilientes ao avanço do mar, como feito em Hamburgo, na Alemanha.

Em Santos, os participantes do workshop discutiram e indicaram algumas medidas de adaptação mais viáveis para a cidade.

As propostas serão incorporadas ao sistema COAST e avaliadas pelos pesquisadores nos próximos dois meses.

As propostas mais indicadas para serem implementadas, em termos de custo e prazo, serão apresentadas em um workshop previsto para ocorrer no dia 1º de dezembro.

“A adaptação é um processo caro. Mas é muito mais custoso se não for feito nada”, avaliou Marengo.

Leia mais sobre o projeto em agencia.fapesp.br/santos_pode_se_tornar_mais_suscetivel_a_inundacoes/21977/). 

Extreme weather: Is it all in your mind? (USA Today)

Thomas M. Kostigen, Special for USA TODAY9:53 a.m. EDT October 17, 2015

Weather is not as objective an occurrence as it might seem. People’s perceptions of what makes weather extreme are influenced by where they live, their income, as well as their political views, a new study finds.

There is a difference in both seeing and believing in extreme weather events, according to the study in the journal Environmental Sociology.

“Odds were higher among younger, female, more educated, and Democratic respondents to perceive effects from extreme weather than older, male, less educated, and Republican respondents,” said the study’s author, Matthew Cutler of the University of New Hampshire.

There were other correlations, too. For example, people with lower incomes had higher perceptions of extreme weather than people who earned more. Those who live in more vulnerable areas, as might be expected, interpret the effects of weather differently when the costs to their homes and communities are highest.

Causes of extreme weather and the frequency of extreme weather events is an under-explored area from a sociological perspective. Better understanding is important to building more resilient and adaptive communities. After all, why prepare or take safety precautions if you believe the weather isn’t going to be all that bad or occur all that often?

The U.S. Climate Extremes Index, compiled by the National Oceanic and Atmospheric Administration (NOAA), shows a significant rise in extreme weather events since the 1970s, the most back-to-back years of extremes over the past decade since 1910, and all-time record-high levels clocked in 1998 and 2012.

“Some recent research has demonstrated linkages between objectively measured weather, or climate anomalies, and public concern or beliefs about climate change,” Cutler notes. “But the factors influencing perceptions of extreme or unusual weather events have received less attention.”

Indeed, there is a faction of the public that debates how much the climate is changing and which factors are responsible for such consequences as global warming.

Weather, on the other hand, is a different order of things: it is typically defined in the here and now or in the immediate future. It also is largely confined, because of its variability, to local or regional areas. Moreover, weather is something we usually experience directly.

Climate is a more abstract concept, typically defined as atmospheric conditions over a 30-year period.

When weather isn’t experiential, reports are relied upon to gauge extremes. This is when beliefs become more muddied.

“The patterns found in this research provide evidence that individuals experience extreme weather in the context of their social circumstances and thus perceive the impacts of extreme weather through the lens of cultural and social influences. In other words, it is not simply a matter of seeing to believe, but rather an emergent process of both seeing and believing — individuals experiencing extreme weather and interpreting the impacts against the backdrop of social and economic circumstances central to and surrounding their lives,” Cutler concludes.

Sophocles said, “what people believe prevails over the truth.” The consequences of disbelief come at a price in the context of extreme weather, however, as damage, injury, and death are often results.

Too many times do we hear about people being unprepared for storms, ignoring officials’ warnings, failing to evacuate, or engaging in reckless behavior during weather extremes.

There is a need to draw a more complete picture of “weather prejudice,” as I’ll call it, in order to render more practical advice about preparing, surviving, and recovering from what is indisputable: extreme weather disasters to come.

Thomas M. Kostigen is the founder of TheClimateSurvivalist.com and a New York Times bestselling author and journalist. He is the National Geographic author of “The Extreme Weather Survival Guide: Understand, Prepare, Survive, Recover” and the NG Kids book, “Extreme Weather: Surviving Tornadoes, Tsunamis, Hailstorms, Thundersnow, Hurricanes and More!” Follow him @weathersurvival, or email kostigen@theclimatesurvivalist.com.

Extending climate predictability beyond El Niño (Science Daily)

Date: April 21, 2015

Source: University of Hawaii – SOEST

Summary: Tropical Pacific climate variations and their global weather impacts may be predicted much further in advance than previously thought, according to research by an international team of climate scientists. The source of this predictability lies in the tight interactions between the ocean and the atmosphere and among the Atlantic, the Pacific and the Indian Oceans. Such long-term tropical climate forecasts are useful to the public and policy makers, researchers say.


This image shows inter-basin coupling as a cause of multi-year tropical Pacific climate predictability: Impact of Atlantic warming on global atmospheric Walker Circulation (arrows). Rising air over the Atlantic subsides over the equatorial Pacific, causing central Pacific sea surface cooling, which in turn reinforces the large-scale wind anomalies. Credit: Yoshimitsu Chikamoto

Tropical Pacific climate variations and their global weather impacts may be predicted much further in advance than previously thought, according to research by an international team of climate scientists from the USA, Australia, and Japan. The source of this predictability lies in the tight interactions between the ocean and the atmosphere and among the Atlantic, the Pacific and the Indian Oceans. Such long-term tropical climate forecasts are useful to the public and policy makers.

At present computer simulations can predict the occurrence of an El Niño event at best three seasons in advance. Climate modeling centers worldwide generate and disseminate these forecasts on an operational basis. Scientists have assumed that the skill and reliability of such tropical climate forecasts drop rapidly for lead times longer than one year.

The new findings of predictable climate variations up to three years in advance are based on a series of hindcast computer modeling experiments, which included observed ocean temperature and salinity data. The results are presented in the April 21, 2015, online issue of Nature Communications.

“We found that, even three to four years after starting the prediction, the model was still tracking the observations well,” says Yoshimitsu Chikamoto at the University of Hawaii at Manoa International Pacific Research Center and lead author of the study. “This implies that central Pacific climate conditions can be predicted over several years ahead.”

“The mechanism is simple,” states co-author Shang-Ping Xie from the University of California San Diego. “Warmer water in the Atlantic heats up the atmosphere. Rising air and increased precipitation drive a large atmospheric circulation cell, which then sinks over the Central Pacific. The relatively dry air feeds surface winds back into the Atlantic and the Indian Ocean. These winds cool the Central Pacific leading to conditions, which are similar to a La Niña Modoki event. The central Pacific cooling then strengthens the global atmospheric circulation anomalies.”

“Our results present a paradigm shift,” explains co-author Axel Timmermann, climate scientist and professor at the University of Hawaii. “Whereas the Pacific was previously considered the main driver of tropical climate variability and the Atlantic and Indian Ocean its slaves, our results document a much more active role for the Atlantic Ocean in determining conditions in the other two ocean basins. The coupling between the oceans is established by a massive reorganization of the atmospheric circulation.”

The impacts of the findings are wide-ranging. “Central Pacific temperature changes have a remote effect on rainfall in California and Australia. Seeing the Atlantic as an important contributor to these rainfall shifts, which happen as far away as Australia, came to us as a great surprise. It highlights the fact that on multi-year timescales we have to view climate variability in a global perspective, rather than through a basin-wide lens,” says Jing-Jia Luo, co-author of the study and climate scientist at the Bureau of Meteorology in Australia.

“Our study fills the gap between the well-established seasonal predictions and internationally ongoing decadal forecasting efforts. We anticipate that the main results will soon be corroborated by other climate computer models,” concludes co-author Masahide Kimoto from the University of Tokyo, Japan.

Journal Reference:

  1. Yoshimitsu Chikamoto, Axel Timmermann, Jing-Jia Luo, Takashi Mochizuki, Masahide Kimoto, Masahiro Watanabe, Masayoshi Ishii, Shang-Ping Xie, Fei-Fei Jin. Skilful multi-year predictions of tropical trans-basin climate variabilityNature Communications, 2015; 6: 6869 DOI: 10.1038/ncomms7869

Previsão do tempo no Sudeste é uma dor de cabeça para cientistas (Folha de S.Paulo)

15/02/2015

Peculiaridades do clima regional tornam difícil saber como ficará o nível do Cantareira mesmo no curto prazo

Área está sujeita à influência de vários fatores complexos, como umidade da Amazônia e frentes frias da Antártida

REINALDO JOSÉ LOPES

COLABORAÇÃO PARA A FOLHA

LUCAS VETTORAZZO

DO RIO

Se a sucessão de boas e más notícias sobre a chuva que abastece os reservatórios de São Paulo parece uma confusão só, não se preocupe: previsões climáticas sobre o Sudeste brasileiro podem confundir até especialistas.

Isso acontece porque a região mais populosa do Brasil ocupa uma área do globo terrestre que recebe todo tipo de influência complexa, desde a umidade oriunda da Amazônia até as frentes frias “sopradas” da Antártida.

Resultado: um nível de incerteza acima do normal numa seara que, por natureza, já é bastante incerta.

“Isso vale principalmente para prever o clima, ou seja, as variações de médio e longo prazo, mas também é verdade, ainda que em grau bem menor, para as previsões de tempo, ou seja, na escala de dias”, diz Tercio Ambrizzi, climatologista da USP.

Portanto, não é que o tempo seja mais instável na área do sistema Cantareira, o mais castigado pela atual crise e agora em ligeira recuperação. O que ocorre é que a região que abastece o Cantareira às vezes pode ficar mais sujeita a variações aleatórias de um sistema climático naturalmente complicado.

TEORIA DO CAOS

“Em escalas maiores do que 15 dias, faz décadas que está comprovado que o clima é caótico”, diz Gilvan Sampaio de Oliveira, meteorologista do Inpe (Instituto Nacional de Pesquisas Espaciais).

“Aliás, foi a partir daí que surgiu a teoria do caos”, afirma ele, referindo-se à ideia de que, em certos fenômenos complexos, pequenas mudanças no começo podem levar a alterações muito maiores e imprevisíveis no fim.

Em regiões tropicais, como é o caso de quase todo o território do Brasil, isso é ainda mais verdadeiro, porque o calor injeta mais energia na atmosfera, fazendo com que alterações do tempo aconteçam com mais velocidade e imprevisibilidade.

Além do calor, porém, o Sudeste também tem a desvantagem de que as variações climáticas por aqui dependem de fatores não oceânicos.

“Quando o clima de uma região depende do oceano, é bem mais fácil prevê-lo porque as variações oceânicas acontecem de forma bem mais lenta do que as da atmosfera”, explica Oliveira. “É o caso do semiárido nordestino, ligado basicamente às condições do oceano Pacífico e do Atlântico tropical. Se é ano de El Niño, com o Pacífico mais aquecido, a tendência é seca no Nordeste.”

Já as chuvas do Sudeste, em especial as de verão, estão ligadas principalmente à ZCAS (Zona de Convergência do Atlântico Sul), formada pela umidade da Amazônia, que se espalha numa grande faixa que atravessa o Brasil Central, e pelas frentes frias antárticas (veja infográfico).

“Quando essa zona se fortalece você pode ter chuva constante por três, quatro, cinco dias, e é bem comum isso acontecer no Carnaval, como inclusive deve acontecer neste ano”, diz Oliveira.

Em 2014 e, em menor grau, também neste ano, contudo, a ZCAS não atuou como deveria, com um bloqueio atmosférico impedindo que as chuvas de verão atingissem o Sudeste (e o Cantareira) em cheio. As chuvas constantes e bem distribuídas voltaram apenas nas últimas semanas, porque a ZCAS parece ter se “ajeitado” de novo.

Mesmo nesse cenário, isso não significa que as chuvas de verão cessem totalmente. Com o calor típico da estação, há um ciclo rápido de evaporação e chuva –mas é um padrão local, o que explica tempestades localizadas e inundações na Grande São Paulo, sem que essas precipitações façam cócegas no Cantareira.

Há ainda outro agravante, que talvez ajude a entender a fama de imprevisível da área. Até pouco tempo atrás, não havia estações pluviométricas confiáveis para medir o volume de chuva na região do Cantareira, conta José Marengo, climatologista do Cemaden (Centro Nacional de Monitoramento e Alertas de Desastres Naturais).

“Os pluviômetros mais próximos eram os de Campos do Jordão. Faltam registros históricos. Não podemos intercalar com os dados de Campos do Jordão porque é outro regime chuva.”

Quebra de protocolo (Folha de S.Paulo)

19/02/2015

O Protocolo de Kyoto –controverso tratado de 1997 para conter a mudança do clima– teve escasso sucesso. A melhor evidência disso está no fato de as negociações internacionais sobre o tema tomarem hoje rumo muito diferente.

Nada assegura, no entanto, que uma trilha bem-sucedida se iniciará na decisiva conferência de Paris, a ser realizada em dezembro.

Neste fevereiro faz dez anos que o protocolo entrou em vigor, após a ratificação por 189 países. O acordo estabelecia que 37 nações industrializadas reduziriam suas emissões de gases do efeito estufa em 5% no período de 2008 a 2012, tomando por base o ano de 1990.

A meta foi alcançada com folga. Os países comprometidos cortaram em 22,6% a poluição que aprisiona radiação solar na atmosfera, aquecendo-a além da conta. Assim, falar em fracasso parece mesquinho.

Ocorre que as emissões globais subiram 16,2% até 2012. O clima mundial seguiu firme na rota do aquecimento porque não participavam do tratado os dois maiores poluidores, China e Estados Unidos.

O primeiro, por ser um país em desenvolvimento –e que desenvolvimento: sua economia cresceu a taxas próximas de 10% ao ano. O segundo, por força da política doméstica, uma vez que a eleição do presidente democrata Barack Obama foi incapaz de reverter o veto congressual a qualquer acordo que excluísse a China.

Ao final do primeiro período de Kyoto, em 2012, tentou-se em Doha (Qatar) um novo e mais ambicioso objetivo: reduzir em 18% as emissões até 2020. Apenas 23 nações aderiram à meta até agora.

O fracasso da via aberta em 1997 e pavimentada em 2005 foi sobretudo político. Obter consenso entre diversos países em torno de objetivos que possam ser monitorados e cobrados por uma instância internacional parece cada vez mais inviável, assim como a transferência de recursos e tecnologia, anátema entre potências desenvolvidas.

A alternativa surgida na tortuosa negociação diplomática sobre mudança do clima, após o fiasco da Cúpula de Copenhague (2009), foi afrouxar compromissos. Eles podem agora ser voluntários, e cada nação propõe quando planeja alcançá-lo e com base em qual ano.

Há amplo ceticismo, porém, quanto à chance de que a estratégia desvinculante produza o resultado esperado, a saber, impedir que o aquecimento ultrapasse 2°C neste século. Além desse limite, a ciência indica risco acentuado de desastres como secas duradouras e enchentes avantajadas.

Todas as atenções se voltam para o fim do outono em Paris.

*   *   *

Kyoto, 10, engatinha

16/02/2015

Protocolo, que entrou em vigor em 2005, fracassou em reduzir emissões mundiais de gases-estufa; para piorar, novas metas, traçadas em 2012, só tiveram 23 adesões

MAURÍCIO TUFFANI

COLABORAÇÃO PARA A FOLHA

Dez anos após ter entrado em vigor, o Protocolo de Kyoto tem um diagnóstico claro: o acordo fracassou em reduzir as emissões mundiais de gases-estufa, que cresceram 16,2% de 2005 a 2012.

O pacto internacional, porém, não foi de todo inócuo e teve certo sucesso em conscientizar a sociedade e implantar projetos ambientais, tecnológicos e de desenvolvimento econômico para prevenir o agravamento do aquecimento global.

Concluído em 1997 em Kyoto, no Japão, o protocolo estabelecia metas de redução das emissões de gases-estufa. Só em 2005 ele adquiriu força para entrar em vigor, com a ratificação pela Rússia.

O protocolo teve 189 ratificações, entre elas a do Brasil, em 2002. Mas suas novas metas de redução de emissões de 2013 a 2020, estabelecidas em 2012 no Qatar, só tiveram até agora 23 adesões.

Em um balanço, a secretaria da Convenção-Quadro das Nações Unidas sobre Mudança Climática (UNFCCC) destacou que 37 países, a maioria da União Europeia, superaram sua meta de reduzir em 5% suas emissões até 2012.

A agência, contudo, deixou de lado os números do aumento global das emissões e o alerta enfático feito em 2014 por seu braço científico, o IPCC (Painel Intergovernamental sobre Mudança Climática): não há mais tempo para reduzir a concentração de gases-estufa para que o aumento médio da temperatura da superfície terrestre até 2100 seja inferior a 2º C.

Essa elevação traria como consequência mais secas, derretimento de geleiras e inundações de zonas costeiras pela elevação dos oceanos.

Para evitar esse cenário, seria preciso reduzir as emissões em 80% até 2050.

PERDAS E GANHOS

“Estou convencida de que sem o protocolo de Kyoto não estaríamos avançados como hoje na crescente penetração das energias renováveis”, disse Christiana Figueres, secretária-executiva da UNFCCC.

Figueres também destacou cerca de 7.800 projetos de apoio a países em desenvolvimento, envolvendo benefícios de até US$ 13,5 bilhões para reduzir emissões por desmate e para “sequestro de carbono” da atmosfera por meio de recuperação e ampliação de florestas.

“Se olharmos quantitativamente para as emissões, o protocolo falhou. Mas sem ele a União Europeia não teria atingido grandes avanços nas reduções”, diz Carlos Nobre, que acaba de assumir o cargo de diretor do Cemaden (Centro de Monitoramento e Alerta de Desastres Naturais).

Nobre ressalta que a Alemanha mostrou que é possível reduzir os gases-estufa sem diminuir seu PIB. “Vejo com otimismo esse efeito pedagógico”, disse Nobre.

Já para o físico da USP e membro do IPCC Paulo Artaxo, ainda que o tratado tenha aumentado a adesão de novas tecnologias e a conscientização para o que ele chama de “problema mais sério já enfrentado pela humanidade”, houve, além do aumento da concentração de carbono na atmosfera, acúmulo de CO2 nos oceanos, o que pode causar desequilíbrios para a vida marinha.

PERSPECTIVAS

Segundo Carlos Rittl, secretário-executivo do Observatório do Clima, a próxima conferência do clima, em dezembro, em Paris, poderá ter avanços graças ao recente acordo entre EUA (que assinaram mas não ratificaram o Protocolo de Kyoto) e China.

Para ele, um dos grandes desafios para os governos, inclusive o do Brasil, é o planejamento econômico e energético. Ele afirma que isso ainda é feito sem assimilar as mudanças climáticas, e a atual crise energética e hídrica do país é prova disso.

Fabio Feldmann, secretário-executivo do Fórum Paulista de Mudanças Climáticas e de Biodiversidade e ex-secretário estadual do Meio Ambiente de São Paulo, afirma ainda que a redução de desmatamentos no Brasil criou uma “falsa impressão” de que o país pode continuar com os mesmos níveis de emissões em outros setores.

De fato, enquanto as emissões por desmates no país diminuíram 64% de 2005 a 2013, as das atividades agropecuárias e do consumo de energia cresceram, respectivamente, 6% e 42%, segundo o Observatório do Clima.

The West without Water: What Can Past Droughts Tell Us About Tomorrow? (Origins)

vol. 8, issue 6 – march 2015

by  B. LYNN INGRAM

Editor’s Note:
Almost as soon as European settlers arrived in California they began advertising the place as the American Garden of Eden. And just as quickly people realized it was a garden with a very precarious water supply. Currently, California is in the middle of a years-long drought and the water crisis is threatening the region’s vital agricultural economy, not to mention the quality of life of its people, plants, and animals. This month B. Lynn Ingram, Professor of Geography and Earth & Planetary Science, examines how a deep historical account of California’s water patterns can help us plan for the future.


The state of California is beginning its fourth year of a serious drought, with no end in sight.

The majority of water in the western United States is delivered by winter storms from the Pacific, and over the past year, those storms were largely blocked by an enormous ridge of high pressure. A relatively wet December has given way to the driest January on record, and currently over 90 percent of California is in severe to exceptional drought.

The southwestern states are also experiencing moderate to severe drought, and this comes on the heels of a very dry decade. This long drought has crept up on the region, partly because droughts encroach slowly and they lack the visual and visceral effects of other, more immediate natural disasters such as earthquakes, floods, or tsunamis.

Meteorologists define drought as an abnormally long period of insufficient rainfall adversely affecting growing or living conditions. But this bland definition belies the devastation wrought by these natural disasters. Drought can lead to failed crops, desiccated landscapes, wildfires, dehydrated livestock, and in severe cases, water wars, famine, and mass migration.

Although the situation in the West has not yet reached such epic proportions, the fear is that if it continues much longer, it could.

Lake Powell, in 2009, showing a white calcium carbonate “bathtub ring” exposed after a decade of drought lowered the level of the reservoir to 60 percent of its capacity. (Photo courtesy of U.S. Bureau of Reclamation.)

In California, reservoirs are currently at only 38 percent of capacity, and the snowpack is only 25 percent of normal for late January. Elsewhere in the Southwest, Lake Powell, the largest reservoir on the Colorado River, is at 44 percent of capacity.

The amount of water transported through irrigation systems to California’s Central Valley—the most productive agricultural region in the world—has been reduced to only 20 percent of customary quantities, forcing farmers to deepen groundwater wells and drill new ones.

Over the past year, 410,000 acres have been fallowed in this vast agricultural region that provides 30 percent of all the produce grown in the United States and virtually all of the world’s almonds, walnuts, and pistachios. As California dries up, food prices might well rise across the nation.

The question on everyone’s mind is when will this dry period finally come to an end and rainfall return to normal—and just what is normal for the U.S. Southwest when it comes to rain?

And with a growing and more urban population and an ever-changing climate, will we ever be free from the threat of long dry periods, with their disruptive effects on food production and the plants and animals that rely on water to survive?

A glance into the history of the Southwest reminds us that the climate and rainfall patterns have varied tremendously over time, with stretches of drought many decades longer than the one we are experiencing now.

Long dry stretches during the Medieval centuries (especially between 900 and 1350 CE) had dramatic effects on the native peoples of the Southwest (the ancestral Pueblo, Hohokam, and Sinagua), including civilizational collapse, violence, malnutrition, and forced social dislocation.

These earlier Americans are a warning to us.

The past 150 years, which we have used as our baseline for assumptions about rainfall patterns, water availability for agriculture, water laws, and infrastructure planning, may in fact be an unusually wet period.

Let’s look at the past few hundred years first and then explore the region’s climate in geological time.

Recent Droughts and the Arid Regions of the United States

John Wesley Powell stands as one of the most extraordinary scientists and explorers in America in the second half of the 19th century.

In 1869 he became the first white man to lead an expedition down the Colorado River and through the Grand Canyon, a feat all the more remarkable considering Powell had lost most of his right arm during the Civil War.

Ten years later, Powell published Report on the Lands of the Arid Regions of the United States, a careful assessment of the region’s capacity to be developed.

In it, Powell argued that very little of the West could sustain agriculture. In fact, his calculations suggested that even if all the water in western streams were harnessed, only a tiny fraction of the land could be irrigated.

Further, Powell believed that growth and development ought to be carefully planned and managed, and that boundaries drawn for new western states ought to follow watersheds to avoid inter-state fighting over precious water resources.

When Powell presented his findings to Congress, politicians howled. Powell found himself denounced by pro-development forces, including railroads and agricultural interests.

Prescient as Powell’s study has proved to be, it was almost entirely ignored at the time.

Instead, those development boosters responded to Powell’s data about the aridity of the west with a novel climatological theory: “Rain follows the plow.” They insisted that agriculture could cause the rains to fall, so like magic the more acres brought under cultivation the more rain farmers would enjoy.

The years surrounding the turn of the 20th century turned out to be unusually wet across much of the region. Hopeful pioneers continued to flock to the West, despite the visible signs of aridity.

They still do. The past century and a half in California and the West has been a period of steady population growth. And today the U.S. Southwest is the fastest-growing region in the United States (which itself is the world’s fourth-fastest-growing nation).

The Dirty Thirties and Beyond

The relatively wet period of the late nineteenth and early twentieth centuries gave way to drought in the late 1920s with the start of the Dust Bowl—now considered to be the United States’ worst climate tragedy.

The years between 1928 and 1939 were among the driest of the 20th century in the American West. This drought had particularly severe effects on California’s developing agricultural industry that were only mitigated by the extensive pumping of groundwater that eventually caused the ground surface in California’s Central Valley to drop by several feet.

Donner Lake, Sierra Nevada Range, California (Photo taken by B. Lynn Ingram).

In the 20th century, the single driest year (rivaling the 2013-2014 water year) was the drought of 1976-1977, extending across the entire state of California and into the Northwest, the Midwest, and the Canadian Prairie region north of Montana.

In California, precipitation levels dropped to less than a quarter of average. Reservoirs dropped to one-third their normal levels, and 7.5 million trees in the Sierra Nevada weakened by drought succumbed to insect related diseases, fueling massive wildfires. Snowfall was extremely sparse, forcing ski areas to close.

The following decade, another six-year drought occurred from 1987 to 1992, and while no single year was as severe as the drought of 1976-1977, the cumulative effects were ultimately more devastating. Annual precipitation attained only 50 percent of the 20th century average, with far-ranging impacts.

In the Sierra Nevada, water-stressed trees suffered widespread mortality from pine bark beetle infestations. Reduced stream flow caused major declines in fish populations, affecting commercial and recreational fisheries by lowering populations of Chinook salmon and striped bass.

By the fourth year of the drought, reservoir storage statewide was down 60 percent, causing a decline in hydroelectric power generation and the imposition of water restrictions including a decrease in agricultural water delivery by 75 percent.

Farmers relied more on groundwater, with private well owners deepening existing wells or drilling new ones. In the San Joaquin Valley, 11 million acre-feet more groundwater was extracted than could be replenished naturally, further lowering already low groundwater levels.

Measuring Droughts over Geological Time

As bad and worrisome as these more recent historical droughts in California and the West were, they pale in comparison to events uncovered in the geological record.

In recent years, earth scientists have been discovering that the climate and weather in the West over the past 100 to 150 years represents only a narrow part of the full range of climate in the region.

By peering deeper into Earth’s history—the past centuries and millennia—the frequency and magnitude of extreme climate events like drought can be better understood.

The evidence comes in various forms, such as mud from the bottom of lakes and ponds, microscopic organisms living in the oceans, bubbles frozen in glaciers, pencil-thin wood cores drilled from trees, and salts precipitating in dried-up lake bottoms.

A cut section of a Giant Sequoia trunk from Tuolumne Grove, Yosemite National Park, California, showing AD dates of fires (photo courtesy of Thomas Swetnam, Laboratory of Tree-Ring Research, University of Arizona).

One of the earliest records of past climate change comes from the rings of the long-lived Douglas fir. Trees are particularly effective recorders of climate because they respond every year to conditions of temperature and precipitation, responses recorded in the growth rings of their trunks.

In a landmark study during the early 1940s, a 600-year record of Colorado River flow using Douglas firs revealed several sustained periods of low water flow and these periods recurred with some regularity.

The reconstruction showed a particularly severe drought in the late 1500s, a drought lasting over a decade that has since shown up in multiple records from throughout the West.

These records also reveal that the driest single year over the past millennium (even drier than the parched 1976-1977 drought) occurred in 1580 CE. Trees across the West either had a narrow ring, or even a missing ring, that year.

Looking at an even broader picture, evidence from the past 10 millennia—a relatively warm era since the last Ice Age, which we call the Holocene—informs us that the severity of past extreme events (including droughts and floods) far exceeds those experienced over the past century and a half.

One of the longest dry periods for California and the West occurred during what is known as the mid-Holocene climatic optimum, a time when much of the earth experienced warmer than average conditions from about 4,500 to 7,500 years ago.

In the American West, there are numerous clues showing that this time period was drier than average for upwards of 1,400 years. These climate extremes caused significant human dislocations and forced native populations to migrate from the desert interiors of the West to the coastal regions.

The Tools for Uncovering Climate History

One of the most vivid clues for understanding the patterns of past drought in the West was revealed in Lake Tahoe toward the end of the Great Dust Bowl of the mid-1930s. At that time, Tahoe’s water level dropped fourteen inches, exposing a mysterious clustering of tree stumps sticking up from the water’s surface along the lake’s southern shore.

These trees attracted the attention of Samuel Harding, an engineering Professor from the University of California, Berkeley. Harding discovered that the trees were large, with trunks as wide as three feet in diameter, and appeared to be firmly rooted in the lake bottom.

Harding reasoned that the trees had grown in this location for a long time to attain such sizes, and since they were now submerged in over twelve feet of water, he surmised that at some time in the past the lake level had been much lower.

Frances Malamud-Roam, B. Lynn Ingram, and Christina Brady coring a small oxbow lake in the Sacramento Valley, California. (Photo taken by Anders Noren, University of Minnesota, LaCore curator.)

After collecting cores through their trunks, he counted up to 150 rings, concluding that it was a dry spell of over a century that caused the lake level to drop, allowing the trees to grow along the former shoreline.

Harding had to wait two decades before he could date this drought, after the invention of radiocarbon dating in the 1950s. Radiocarbon measurements of the outermost rings of the tree stumps showed that these trees died approximately 4,800 years ago.

Decades later, more evidence emerged from Lake Tahoe during another of California’s droughts in the late 1980s, when the lake’s surface dropped again, exposing even more tree stumps.

This time, it was an archaeologist, Susan Lindstrom, who noticed the tops of trees sticking out of the water along Tahoe’s southern shore. Donning scuba gear, Lindstrom was able to find fifteen submerged tree stumps that had escaped Harding’s attention, some measuring up to three and a half feet in diameter.

The radiocarbon dates from this much larger population of trees refined and extended the boundaries of the mid-Holocene drought, moving the beginning to as early as 6,290 years ago, and the ending to 4,840 years ago.

These stumps, located deeper in the lake, showed that the lake level had dropped by even more than Harding originally thought – by more than 20 feet. Lindstrom and other researchers have since located tree stumps in more places around the shores of Lake Tahoe and in other Sierran lakes.

Sediment core taken by Frances Malamud-Roam and B. Lynn Ingram from beneath San Francisco Bay, California. (Photo taken by B. Lynn Ingram.)

Geologists have also discovered more evidence from sediment cores taken from beneath lakes revealing the wide extent of this drought—across California and the Great Basin.

The archaeological records show that native populations migrated from the inland desert regions to the California coast at this time, likely in search of water and other resources during this prolonged drought.

Another dry millennium began about 3,000 years after the mid-Holocene drought ended. Evidence for this prolonged drought was found throughout California and the West.

One study, conducted in my laboratory at UC Berkeley, examined sediments accumulating beneath the San Francisco Bay estuary. These sediments contain information about precipitation over the entire drainage basin of the Sacramento and San Joaquin Rivers—an area that covers 40 percent of California.

Frances Malamud-Roam and Anders Noren coring marsh sediments adjacent to San Francisco Bay (Photo taken by B. Lynn Ingram)

Rivers draining the Sierra Nevada Range and Central Valley flow through San Francisco Bay and out the Golden Gate to the Pacific Ocean. In the Bay, fresh river water meets and mixes with the incoming ocean water, producing a range of salinity: fresh at the Delta, saline in the Central bay near the Golden Gate, and brackish in between.

Organisms growing in the Bay record the salinity in their shells, which then sink to the bottom and are preserved in the sediments. We took sediment cores from beneath the Bay and analyzed the chemistry of the fossil shells, allowing us to reconstruct past salinity, and therefore past river flow.

These studies showed that droughts lasting over a decade occurred regularly over the past two millennia, at intervals of 50 to 90 years. The cores also revealed a period of high salinity that began about 1,700 years ago and ending about 700 years ago, suggesting another prolonged drought.

We conducted a related study with Professor Roger Byrne in the Geography Department at UC Berkeley, coring the tidal marshlands surrounding the bay to assess the impact of this drought on this ecosystem.

These marshes have grown up around the edges of San Francisco Bay for the past 5,000 years or so, forming peat. The marsh peats contain fossil plants and chemical evidence for past periods of wetter and drier conditions in the watershed.

A drought in the watershed, if prolonged and severe, can cause higher salinity downstream in the estuary as the inflow of fresh water drops. In response, salt-tolerant species in the marshes expand further inland toward the Delta and the fresh water species retreat. Conversely, unusually wet winters generate fresher conditions in the estuary, leading to an expansion of freshwater-adapted species.

We analyzed the pollen and plant remains, carbon chemistry of the peats, and diatoms—the microscopic phytoplankton that grow in the marshes and produce tiny silica shells.

All of this evidence showed that the average freshwater inflow to San Francisco Bay was significantly lower than today’s levels for a thousand years, between 1,750 and 750 years ago.

The peak of this low-inflow interval, with freshwater flows 40 percent below average levels, occurred approximately 900 to 1,200 years ago, during a time when global temperatures were high, known as the Medieval Warm Period.

Mono Lake, showing calcium carbonate “tufa tower” formations that originally formed beneath the lake but are now exposed after the water level dropped. The eastern flank of the Sierra Nevada range is shown in the background. (Photo by D. J. DePaolo.)

Evidence for this drought was also discovered in an ancient lake situated east of the Sierra Nevada. Geography Professor Scott Stine analyzed the sedimentary sequences in Mono Lake, delineating patterns of alternately higher and lower lake levels for the past 4,000 years.

Mono Lake experienced an extended low stand that began about 1,600 years ago, dropping to an even lower level 700 to 1,200 years ago. During the 1980s drought, Stine also discovered large tree stumps submerged in Mono Lake.

Much like the tree stumps discovered in Lake Tahoe, these submerged trees indicated that at one time the lake was so small that its shoreline was several tens of feet lower than the present shoreline, when the trees now underwater could grow on dry ground. Stine went on to discover similar submerged tree stumps in lakes, marshes, and rivers throughout the central and southern Sierra Nevada Range.

By counting their growth rings, Stine determined that they had lived up to 160 years. Based on the amount the lake level dropped, he calculated that the average annual river flows in the region were only 40 to 60 percent of what they were in the late 20th century.

Radiocarbon dates of the outer growth layers of these tree stumps revealed that these trees clustered around two distinct periods, now known as the “Medieval Megadroughts”: CE 900 to 1100 and CE 1200 to 1350.

An ancient tree stump submerged in the West Walker River, eastern Sierra Nevada. (Photo courtesy of D. J. DePaolo.)

Across North America, tree-ring studies indicate that climate conditions over the past two millennia became steadily more variable (shifting between drier and wetter periods), with especially severe droughts between CE 900 and 1400.

These records show that over half the American West suffered severe drought between CE 1021 and CE 1051, and from CE 1130-1170, CE1240-1265 and CE 1360-1382.

The warm and dry conditions of the Medieval period spawned larger and more frequent wildfires, as recorded in the trunks of Giant sequoias—the massive redwoods growing in about 75 distinct groves along the mid-elevations of the western Sierra Nevada. These spectacular trees can live up to 3,200 years or more, and have exceeded 250 feet in height and 35 feet in diameter.

Thomas Swetnam, the current Director of the Laboratory of Tree Ring Research at the University of Arizona, discovered that the trees carry scars on their annual growth rings that indicate past fires in the region.

Swetnam sampled giant sequoias from five groves between Yosemite National Park and Sequoia National Park, far enough apart that individual fires could not have spread from one grove to the next. He dated the trees using ring-width patterns, and recorded the fire scars contained within annual rings.

His analysis reveals that during the Medieval period, from 1,200 to 700 years ago, an average of thirty-six fires burned every century.

During the centuries preceding the Medieval period (from about 1,500 to 1,200 years ago) and immediately following it (from about 700 years ago to the current century), the fire frequency was substantially lower, with an average of 21 fires per century.

The Human Costs of Droughts Then and Now

The archaeological record suggests that the extended periods of drought in the Medieval era caused severe hardship for both coastal and inland peoples— particularly the ancestral Pueblo communities—as dwindling resources increased disease, malnutrition, and warfare. Long inhabited sites were abandoned as the desperate populations wandered in search of new water sources.

Ancient pueblo cliff dwelling at Mesa Verde, southwestern Colorado. (Photo taken by B. Lynn Ingram)

Much of what archaeologists know about the ancestral Pueblo comes from pueblo and cliff dwellings from the four corners region, including Chaco Canyon in northwestern New Mexico, Mesa Verde in southwestern Colorado, and Canyon de Chelly in northeastern Arizona.

Chaco Canyon in New Mexico was the site of one of the most extensive of the ancestral Pueblo settlements. At its peak, during the 11th and early 12th centuries CE, Chaco Canyon had great pueblos the size of apartment blocks housing hundreds of residents in large, high-ceilinged rooms.

These settlements were supported by agriculture, allowing people to settle in one place year-round. Most of the farming depended on annual rains, supplemented by water from nearby streams and groundwater.

But over time, the climate became increasingly arid and unpredictable. The ancestral Pueblo farmers were forced to build an extensive system of diversion dams and canals, directing rainwater from the mesa tops to fields on the canyon floor, allowing them to expand the area of arable land.

The population in the four corners region swelled throughout the 11th and 12th centuries CE—but then collapsed.

Another ancient society, the Hohokam, lived in central Arizona near the confluence of Arizona’s only three rivers, the Gila, Verde, and Salt. The Hohokam civilization thrived in central Arizona for a thousand years, building an extensive network of integrated canal systems, capable of transporting large volumes of water long distances.

At their peak, an estimated 40,000 Hohokam lived in Arizona, but they suddenly vanished in the mid-15th century.

Montezuma’s Castle, a cliff dwelling occupied by the Sinagua, located just north of Camp Verde in central Arizona. (Photo by B. Lynn Ingram.)

In northern Arizona, between Phoenix and Flagstaff, the Sinagua culture also thrived during this period. As the climate turned drier, they built cliff dwellings in central Arizona, suggesting that resources became scarce, forcing them to build fortified dwellings with hidden food storage areas. The Sinagua also disappeared about the same time as the Hohokam.

All of these societies were flourishing prior to a rather abrupt collapse. The archaeological record of the last decades of the ancestral Pueblo in Chaco Canyon abounds with signs of suffering.

Skeletal remains show signs of malnutrition, starvation and disease; life spans declined and infant mortality rates increased. Evidence of violence, possibly warfare, was found in mass graves containing bones penetrated with arrowheads and teeth marks, and skulls bearing the scars of scalping.

Piles of belongings were found, apparently left behind as the people abandoned their settlements and fled, some to live in fortified hideouts carved in the cliff faces, protecting their hoarded food from enemies.

The unusually dry climate of the Medieval period also appeared to have tested the endurance and coping strategies of even the well-adapted native populations in California.

The skeletal remains show that life in the interior of California was particularly difficult, as the drought severely reduced sources of food (nuts, plants, deer, and other game). Settlements along rivers were abandoned, and trade between inland and coastal groups broke down. As water supplies dried up, conflicts – even battles – between groups arose over territory and food and water resources.

The Watery Lessons of the Past

The “Medieval Drought” serves as a model for what can happen in the West. It also provides an important impetus for water sustainability planning. And the hardships suffered by the first human inhabitants in the West provide important lessons.

For instance, during extended periods of abundant moisture, some societies experienced rapid population growth, leaving them vulnerable to collapse when the climate inevitably turned dry again.

Modern societies in the West have followed a similar path over the past century— after a century of fairly abundant moisture, the population in this region has exploded (and become more urbanized).

Modern engineering has allowed the exploitation of all available water sources for human use, and western water policy has favored water development for power, cities, and farms over sustainability of the environment and ecosystems.

These policies have allowed populations to grow to the limit that this region can support, leaving us vulnerable during extended drier conditions.

The longest six-year droughts experienced by the West over the past century are meager by comparison, despite the extreme hardship they brought to the region.

In fact, in the context of the longer-term climate history, the 20th century actually stands out as one of the wettest over the past 1,300 years, yet the droughts of the mid-1920s, 1977 and the late 1980s caused immense hardship for our society, based as it is upon heavy water usage.

In addition, future changes in the global climate will interact with the natural cycles of drought in California and the West in ways that are difficult to predict. Climate models predict that warming will likely make the extreme events, particularly floods and droughts, even larger and more frequent.

Some of these impacts have already begun. Over the past two decades, warming and an earlier start of the spring season have caused forest fires to become more frequent and intense.

A warmer climate will also bring less precipitation that falls as snow. The American West depends on snow-bearing winter storms for a natural water reservoir. This snow begins melting in the late spring, and continues into the summer, filling streams, lakes, and reservoirs that sustain natural ecosystems throughout the dry summer months.

The snow pack supports cities and irrigated agriculture, providing up to 80 percent of the year’s water supply across the West. As the region warms, the snow that does fall will melt faster and earlier in the spring, rather than melting during the late spring and summer, when it is so critically needed.

The message of past climates is that the range of “normal” climate is enormous—and we have experienced only a relatively benign portion of it in recent history. The region’s climate over the past decade has been dry when compared to the 20th century average, suggesting a return to a drier period.

This past year was also the warmest on record in the American West, and the ten hottest years on record occurred since 1997. The position of inhabitants of the West is precarious now and growing more so.

As we continue with an unsustainable pattern of water use, we become more vulnerable each year to a future we cannot control. It is time for policy makers in the West to begin taking action toward preparing for drier conditions and decreased water availability.


Read more from Origins on Water and the Environment: The World Water CrisisThe River JordanWho Owns the Nile?The Changing ArcticOver-Fishing in American WatersClimate Change and Human Population; and the Global Food Crisis.


Suggested Reading

Benson, L., Kashgarian, M., Rye, R., Lund, S., Paillet, F., Smoot, J., Kester, C., Mensing, S., Meko, D. and Lindstrom, S., 2002. “Holocene Multidecadal and Multi-centennial Droughts Affecting Northern California and Nevada.” Quaternary Science Reviews 21, 659-682.

Bradley, R.S., Briffa, K.R., Cole, J., Hughes, M.K., and Osborn, T.J., 2003. “The climate of the last millennium.” In: Alverson, K, Bradley, R.S., and Pedersen, T.F. (Eds.), Paleoclimate, Global Change and the Future, Springer Verlag, Berlin, pp. 105-49.

Brunelle, A. and Anderson, R.S., 2003. “Sedimentary charcoal as an indicator of late-Holocene drought in the Sierra Nevada, California, and its relevance to the future. “ The Holocene 13(1), 21-28.

Cayan, D. R., S. A. Kammerdiener, M. D. Dettinger, J. M. Caprio, and D. H. Peterson, 2001. “Changes in the onset of spring in the Western United States.” Bull. Am. Met. Soc., 82, 399-415.

Fagan, B., 2003. Before California: an Archaeologist Looks at Our Earliest Inhabitants. Rowman and Littlefield Publishers, Inc, Lanham, MD. 400 p.

Gleick, P.H. and E.L. Chalecki. 1999.” The impacts of climatic changes for water resources of the Colorado and Sacramento-San Joaquin river basins.” Journal of the American Water Resources Association, Vol. 35, No. 6, pp.

Hughes, M.K. and Brown, P.M., 1992. “Drought frequency in central California since 101 B.C. recorded in giant sequoia tree rings.” Climate Dynamics 6,161-197

Ingram, B. Lynn and Malamud-Roam, F. (2013) The West without Water: What past floods, droughts, and other climatic clues tell us about tomorrow. UC Press, 256 pages.

Ingram, B. L., Conrad, M.E., and Ingle, J.C., 1996. “A 2000-yr record of Sacramento-San Joaquin River inflow to San Francisco Bay estuary, California.” Geology 24, 331-334.

Lightfoot, K., 1997. “Cultural construction of coastal landscapes: A middle Holocene perspective from San Francisco Bay.” In: Erlandson, J. and Glassow, M. (eds), Archaeology of the California Coast during the Middle Holocene, 129-141. Series, Perspectives in California Archaeology 4, Institute of Archaeology, Univ. of California.

Malamud-Roam, F. and B.L. Ingram. 2004. “Late Holocene d13C and pollen records of paleosalinity from tidal marshes in the San Francisco estuary.” Quaternary Research 62, 134-145.

Stahle, D. W., Cook, E. R., Cleaveland, M. K., Therrell, M. D., Meko, D. M., Grissino-Mayer, H. D., Watson, E., and Luckman, B., 2000. “Tree-ring data document 16th century megadrought over North America.” EOS Transactions of the American Geophysical Union 81 (12), 121-125.

Stine, S., 1990. “Past Climate At Mono Lake.” Nature 345: 391.

Stine, S., 1994. “Extreme and persistent drought in California and Patagonia during mediaeval time.” Nature 369: 546-549.

Swetnam, T.W. 1993. “Fire history and climate change in Giant Sequoia groves.” Science 262, 885.

Grupo de especialistas divulga previsão do clima para o próximo trimestre (MCTI)

Na primeira reunião de 2015 do Grupo de Trabalho em Previsão Climática Sazonal do Ministério da Ciência, Tecnologia e Inovação, pesquisadores alertam que haverá chuvas abaixo da média no Norte e Nordeste e acima da média no Sul do País

Chuvas abaixo da média na região Semiárida do Nordeste e na região Norte do Brasil, com possibilidade de queimadas e incêndios em Roraima, e continuidade de precipitação acima da média na região Sul. Essas são as tendências climáticas para os próximos três meses (fevereiro, março e abril). Elas foram apresentadas nesta sexta-feira (16) na primeira reunião de 2015 do Grupo de Trabalho em Previsão Climática Sazonal (GTPCS) do Ministério da Ciência, Tecnologia e Inovação (MCTI).

Paulo Nobre, pesquisador do Instituto Nacional de Pesquisas Espaciais (Inpe/MCTI), atribuiu os resultados da avaliação do grupo à continuidade do fenômeno El Niño. “Temos uma condição sazonal dessas três regiões onde é possível hoje cientificamente e tecnologicamente fazer essas previsões”, afirmou o especialista que conduziu as atividades do primeiro encontro do GTPCS.

Participam do grupo de trabalho, instituído pelo MCTI em novembro de 2013, as principais lideranças na área de previsão climática no País. A cada mês os especialistas se reúnem para traçar prognósticos para o trimestre seguinte. O objetivo é dar subsídios aos tomadores de decisões sobre o cenário climático que se aproxima.

O secretário de Políticas e Programas de Pesquisa e Desenvolvimento do MCTI, Carlos Nobre, alertou que a previsão climática para o próximo trimestre inspira atenção. “O Brasil está vivendo um momento de diferentes extremos climáticos em diferentes partes do país com impactos na economia e na sociedade”, destacou o secretário que também coordena do GTPCS. “As informações geradas pelo grupo de trabalho alimentam imediatamente ministérios e a presidência da República para que sejam tomadas as medidas necessárias.”

Na abertura do encontro, que aconteceu pela primeira vez em Brasília, o ministro da Ciência, Tecnologia e Inovação, Aldo Rebelo, enfatizou a importância de haver previsão climática de curto prazo. “O trabalho dos pesquisadores do GTPCS já contribuiu no ano passado para reduzir os danos da seca no Nordeste e das enchentes em Rondônia”, exemplificou.

Participam do grupo pesquisadores do Centro de Previsão de Tempo e Estudos Climáticos (CPTEC) do Inpe; do Centro de Ciência do Sistema Terrestre (CCST); do Centro Nacional de Monitoramento e Alertas de Desastres Naturais (Cemaden/MCTI); e do Instituto Nacional de Pesquisas da Amazônia (Inpa/MCTI). A cada reunião um dos membros conduzirá as atividades. Nesta sexta, o meteorologista Paulo Nobre, pesquisador do Inpe, coordenou os trabalhos.

Para outras regiões do país não há previsibilidade climática, a exemplo do Sudeste. “O Nordeste, por exemplo, é a região com maior previsibilidade sazonal porque tem a dependência do Oceano e um tempo de variação bem lento. Na região Sudeste, o que causa chuva são as frentes frias que tem um tempo de previsibilidade de uma semana, no máximo duas”, explica Paulo Nobre, pesquisador do Inpe. No limite do conhecimento científico o que se pode afirmar é que as chuvas continuarão abaixo da média neste período.

Acesse aqui o relatório completo emitido pelo GTPCS.

(MCTI)

http://www.mcti.gov.br/visualizar/-/asset_publisher/jIPU0I5RgRmq/content/grupo-de-especialistas-divulga-previsao-do-clima-para-o-proximo-trimestre?redirect=/&

Brasil terá Plano Nacional de Adaptação às Mudanças Climáticas (Envolverde)

10/12/2014 – 10h16

por Redação da Envolverde

mudancasclimaticas1 Brasil terá Plano Nacional de Adaptação às Mudanças Climáticas

Sociedade civil participa da elaboração do plano enviando documento com contribuições ao Ministério do Meio Ambiente (MMA).

Em meio à 20ª Conferência das Partes (COP 20) da Convenção-Quadro das Nações Unidas sobre Mudança do Clima (Convenção do Clima), um acontecimento marcou a agenda climática do Brasil. A sociedade civil entregou um documento de contribuições ao Ministério do Meio Ambiente (MMA) para que seja levado em consideração na elaboração do Plano Nacional de Adaptação às Mudanças Climáticas (PNA).

Esse plano, que está em fase de finalização, tem por objetivo reunir as diretrizes para promover medidas de adaptação às mudanças climáticas no Brasil, abordando custos, efetividade e benefícios das medidas sugeridas. A previsão é que ele seja divulgado em 2015 e o prazo para a entrega das sugestões da sociedade civil à chamada pública é 15 de dezembro de 2014.

O estudo para contribuir com o PNA tem como título ”Adaptação Baseada em Ecossistemas (AbE): oportunidades para políticas públicas em mudanças climáticas” e foi encomendado pela Fundação Grupo Boticário de Proteção à Natureza, com apoio do Observatório do Clima – rede de ONGs que atuam na agenda climática brasileira. Desde a elaboração do Termo de Referência para orientação do estudo, a Fundação Grupo Boticário contou com o apoio do Observatório do Clima, e interagiu com o MMA. O estudo contempla recomendações práticas direcionadas a tomadores de decisão, considerando aspectos ambientais e econômicos, para a inserção de uma estratégia de Adaptação baseada em Ecossistemas no PNA e em outras políticas públicas pertinentes. O gerente de Estratégias de Conservação da Fundação Grupo Boticário, André Ferretti, ressalta a importância dessa abertura do governo. “A participação do terceiro setor na criação de políticas públicas que preconizem a adaptação às mudanças climáticas de forma adequada é muito importante, pois mostra que estamos atentos às necessidades do país”.

Segundo ele, a sociedade civil possui um olhar diferente e complementar ao do governo e essa proximidade entre as duas partes é essencial. “Assim, conseguimos cobrar mais intensamente uma posição arrojada e assertiva no que diz respeito às mudanças do clima”, diz Ferretti. O documento de sugestões abordará principalmente a Adaptação baseada em Ecossistemas (AbE), que considera a gestão da biodiversidade e dos serviços ambientais como parte de uma estratégia completa para ajudar pessoas a se prepararem para os efeitos adversos das mudanças climáticas, a exemplo das secas e enchentes extremas.

“Acreditamos que um documento orientador nacional terá um papel fundamental no apoio e divulgação a práticas de AbE no Brasil, ampliando a possibilidade de financiamentos dessas iniciativas, incluindo essas práticas nas políticas estaduais e municipais”, afirma Ferretti. Para ele, as soluções naturais baseadas em ecossistemas geram benefícios adicionais para a sociedade, como a captura e armazenamento de carbono, a conservação da biodiversidade, a infiltração da água da chuva e regularização da vazão dos rios, ou a produção de alimentos, sendo muitas vezes mais eficientes em termos de custos do que outras formas de adaptação baseadas em grandes obras de engenharia. O gerente cita como exemplo um caso no Vietnã, em que se constatou que a plantação e a manutenção de manguezais podem agir como quebra-mares e proteger a zona costeira com custos muito mais baixos do que a reparação mecânica da erosão de diques induzida por ondas, segundo dados da publicação “A Economia dos Ecossistemas e da Biodiversidade”, de 2009.

Para debater as mudanças climáticas e mensurar seus efeitos sobre a biodiversidade da Mata Atlântica, a Fundação Grupo Boticário apoia, desde 2011, projetos voltados para o estudo dessa temática por meio do edital Bio&Clima Lagamar, cuja área de abrangência engloba o Mosaico de Áreas Protegidas do Lagamar (litoral paranaense e o litoral sul de São Paulo). Além disso, com o objetivo de ampliar a pesquisa sobre o tema nesta região, a Fundação Grupo Boticário firmou uma parceria com a FAPESP, que resultou em uma chamada conjunta para apoio a projetos, com o valor total de R$ 5 milhões.

Sobre a Fundação Grupo Boticário: a Fundação Grupo Boticário de Proteção à Natureza é uma organização sem fins lucrativos cuja missão é promover e realizar ações de conservação da natureza. Criada em 1990 por iniciativa do fundador de O Boticário, Miguel Krigsner, a atuação da Fundação Grupo Boticário é nacional e suas ações incluem proteção de áreas naturais, apoio a projetos de outras instituições e disseminação de conhecimento. Desde a sua criação, a Fundação Grupo Boticário já apoiou 1.417 projetos de 481 instituições em todo o Brasil. A instituição mantém duas reservas naturais, a Reserva Natural Salto Morato, na Mata Atlântica; e a Reserva Natural Serra do Tombador, no Cerrado, os dois biomas mais ameaçados do país.  Outra iniciativa é um projeto pioneiro de pagamento por serviços ambientais em regiões de manancial, o Oásis. Na internet, no Twitter  e no Facebook.

Sobre o Grupo Boticário: constituído em 2010, o Grupo Boticário é uma referência internacional no varejo de beleza. Controla quatro unidades de negócio: O Boticário; Eudora; quem disse, berenice?; e The Beauty Box, e é mantenedor da Fundação Grupo Boticário de Proteção à Natureza. Está presente em sete países e conta com uma força de trabalho composta por sete mil colaboradores diretos que acreditam que beleza não é o que a gente sonha, imagina ou quer. Beleza é o que a gente faz.

(Fundação Grupo Boticário)

Early warning signals of abrupt climate change (Science Daily)

Date: December 8, 2014

Source: University of Exeter

Summary: A new study has found early warning signals of a reorganization of the Atlantic ocean’s circulation which could have a profound impact on the global climate system.


Drought (stock image). Credit: © carloscastilla / Fotolia

A new study by researchers at the University of Exeter has found early warning signals of a reorganisation of the Atlantic ocean’s circulation which could have a profound impact on the global climate system.

The research, published today in the journal Nature Communications, used a simulation from a highly complex model to analyse the Atlantic Meridional Overturning Circulation (AMOC), an important component of the Earth’s climate system.

It showed that early warning signals are present up to 250 years before it collapses, suggesting that scientists could monitor the real world overturning circulation for the same signals.

The AMOC is like a conveyor belt in the ocean, driven by the salinity and temperature of the water. The system transports heat energy from the tropics and Southern Hemisphere to the North Atlantic, where it is transferred to the atmosphere.

Experiments suggest that if the AMOC is ‘switched off’ by extra freshwater entering the North Atlantic, surface air temperature in the North Atlantic region would cool by around 1-3°C, with enhanced cooling of up to 8°C in the worst affected regions.

The collapse would also encourage drought in the Sahel — the area just south of the Sahara desert — and dynamic changes in sea level of up to 80cm along the coasts of Europe and North America.

“We found that natural fluctuations in the circulation were getting longer-lived as the collapse was approached, a phenomenon known as critical slowing down,” said lead author Chris Boulton.

“We don’t know how close we are to a collapse of the circulation, but a real world early warning could help us prevent it, or at least prepare for the consequences” adds co-author Professor Tim Lenton.

The study is the most realistic simulation of the climate system in which this type of early warning signal has been tested.

“The best early warning signals in the model world are in places where major efforts are going into monitoring the circulation in the real world — so these efforts could have unexpected added value’ adds Professor Lenton.


Journal Reference:

  1. Chris A. Boulton, Lesley C. Allison, Timothy M. Lenton. Early warning signals of Atlantic Meridional Overturning Circulation collapse in a fully coupled climate modelNature Communications, 2014; 5: 5752 DOI: 10.1038/ncomms6752

Climate change in the news (DISCCRS)

DISCCRS News – December 9, 2014 (Nancy Rose)

NEWS

‘Green Revolution’ changes breathing of the biosphere – Science Codex – November 19, 2014 – http://www.sciencecodex.com/green_revolution_changes_breathing_of_the_biosphere-145973

Increasing greenhouse gases linked to rains over Africa thousands of years ago – NSF Press Release 14-165 – December 4, 2014 – http://www.nsf.gov/news/news_summ.jsp?cntn_id=133514&WT.mc_id=USNSF_51&WT.mc_ev=click

Only 60 years of farming left if soil degradation continues – Thomson Reuters Foundation – December 5, 2014 – http://www.trust.org/item/20141205165214-tj9dz/?source=fiOtherNews3

Lima climate talks: EU and US at odds over legally binding emissions targets – Guardian – December 2, 2014 – http://www.theguardian.com/environment/2014/dec/02/lima-climate-talks-eu-and-us-at-odds-over-legally-binding-emissions-targets

This year may be hottest on record; adds urgency to climate talks-UN – Reuters – December 3, 2014 – http://www.reuters.com/article/2014/12/03/climatechange-lima-temperatures-update-idUSL2N0

Adapting to a warmer climate could cost almost three times as much as thought, says UN report – Guardian – December 5, 2014 – http://www.theguardian.com/environment/2014/dec/05/adapting-to-a-warmer-climate-could-cost-almost-three-times-as-much-as-thought-says-un-report

China says climate aid inadequate, especially Australia – Reuters – December 4, 2014 – http://www.reuters.com/article/2014/12/04/us-climatechange-lima-china-idUSKCN0JI29A20141204

Better policy, finance needed to balance forests and farming – experts – Thomson Reuters Foundation – December 7, 2014 – http://www.trust.org/item/20141207134326-v1b7a/?source=fiOtherNews3

Climate adaptation costs soaring, funding to fall short – UN – Thomson Reuters Foundation – December 5, 2014 – http://www.trust.org/item/20141205190231-37s41/?source=fiOtherNews3

UN: climate change costs to poor underestimated – Associated Press – December 5, 2014 – http://bigstory.ap.org/article/49a444ed2b1646509f29a1f632d2e1c0/un-climate-change-costs-poor-underestimated

Rift widens among greens over burying carbon as climate fix – Reuters – December 5, 2014 – http://www.reuters.com/article/2014/12/05/us-climatechange-lima-greens-idUSKCN0JJ21R20141205

Australia named worst-performing industrial country on climate change – Guardian – December 8, 2014 – http://www.theguardian.com/environment/2014/dec/08/australia-named-worst-performing-industrial-country-on-climate-change

Green Climate Fund plans to turn on money tap in 2015 – director – Thomson Reuters Foundation – December 4, 2014 – http://www.trust.org/item/20141204232229-6wev7/?source=fiOtherNews3

Green groups urge climate fund to exclude fossils – Associated Press – December 3, 2014 ?
http://bigstory.ap.org/article/7eeaa0970a2b4adea736bc31ebed99b0/green-groups-urge-climate-fund-exclude-fossilsTN16T20141203

Liquid Light finds use for polluting CO2 gas – Guardian – December 8, 2014 – http://www.theguardian.com/technology/2014/dec/08/liquid-light-co2-greenhouse-gas-plastics-pet

Not long to wait till released CO2 turns up temperature – Climate News Network – December 7, 2014 – http://www.climatenewsnetwork.net/not-long-to-wait-till-released-co2-turns-up-temperature/

Warming reaches maximum 10 years after carbon dioxide emission – Carnegie Institution for Science Press Release (via AAAS EurekAlert) – December 2, 2014 – http://www.eurekalert.org/pub_releases/2014-12/ci-wrm120114.php

Study finds early warning signals of abrupt climate change – University of Exeter Press Release (via AAAS EurekAlert) – December 8, 2014 – http://www.eurekalert.org/pub_releases/2014-12/uoe-sfe120514.php

Warmer seas could cause faster melting of Antarctic ice leading to rising sea levels, says study – Guardian – December 5, 2014 – http://www.theguardian.com/environment/2014/dec/05/warmer-seas-could-cause-faster-melting-polar-ice-rising-sea-levels

How Scientists Unraveled the El Nino Mystery – Climate Central – December 7, 2014 – http://www.climatecentral.org/news/how-scientists-unraveled-the-el-nino-mystery-18412

The End and Beginning of the Arctic – Climate Central – December 6, 2014 – http://www.climatecentral.org/news/the-end-and-beginning-of-the-arctic-18407

Warm Water Invasion Is Fueling Striking Antarctic Ice Melt – Climate Central – December 4, 2014 – http://www.climatecentral.org/news/warm-water-invasion-fueling-striking-antarctic-ice-melt-18401

Antarctica: Heat comes from the deep – Helmholtz Centre for Ocean Research Kiel Press Release (via AAAS EurekAlert) – December 4, 2014 – http://www.eurekalert.org/pub_releases/2014-12/hcfo-ahc120114.php

Warm water undermining Antarctica’s ice shelves – New Scientist – December 4, 2014 – http://www.newscientist.com/article/dn26657-warm-water-undermining-antarcticas-ice-shelves.html#.VIY-4iiv1sQ

Hotter, weirder: How climate has changed Earth – Associated Press – December 2, 2014 – http://bigstory.ap.org/article/0ec806f3702b4b61b65f7d3de3867729/hotter-weirder-how-climate-has-changed-earth

Concluído primeiro recenseamento de nuvens do Brasil (Fapesp)

01 de dezembro de 2014

Por Karina Toledo

Agência FAPESP – Para conseguir prever com precisão eventos extremos, como tempestades, ou simular cenários de impactos das mudanças climáticas, é preciso avançar no conhecimento dos processos físicos que ocorrem no interior das nuvens e descobrir a variação de fatores como o tamanho das gotas de chuva, a proporção das camadas de água e de gelo e o funcionamento das descargas elétricas.

Com esse objetivo, uma série de campanhas para coleta de dados foi realizada entre 2010 e 2014 em seis cidades brasileiras – Alcântara (MA), Fortaleza (CE), Belém (PA), São José dos Campos (SP), Santa Maria (RS) e Manaus (AM) – no âmbito de um Projeto Temático FAPESP coordenado por Luiz Augusto Toledo Machado, do Instituto Nacional de Pesquisas Espaciais (Inpe). Essas campanhas contaram com a participação de pesquisadores da Universidade de São Paulo (USP) e de diversas faculdades de Meteorologia no Brasil, que sediaram os experimentos.

Os principais resultados da iniciativa, conhecida como “Projeto Chuva”, foram descritos em um artigo de capa do Bulletin of the American Meteorological Society, revista de grande impacto na área de meteorologia.

Segundo Machado, as regiões escolhidas para a pesquisa de campo representam os diferentes regimes de precipitação existentes no Brasil. “É importante fazer essa caracterização regional para que os modelos matemáticos possam fazer previsões em alta resolução, ou seja, em escala de poucos quilômetros”, disse o pesquisador.

Um conjunto comum de instrumentos – que inclui radares de nuvens de dupla polarização – foi usado nos diferentes sítios de forma que as medidas pudessem ser comparadas e parametrizadas para modelagem.

O radar de dupla polarização, em conjunto com outros instrumentos, envia ondas horizontais e verticais que, por reflexão, indicam o formato dos cristais de gelo e das gotas de chuva, ajudando a elucidar a composição das nuvens e os mecanismos de formação e intensificação das descargas elétricas durante as tempestades. Também foram coletados dados como temperatura, umidade e composição de aerossóis.

Além disso, experimentos adicionais distintos foram realizados em cada uma das seis cidades. No caso de Alcântara, onde a coleta de dados ocorreu em março de 2010, o experimento teve como foco o desenvolvimento de algoritmos de estimativa de precipitação para o satélite internacional Global Precipitation Measurement (GPM) – lançado em fevereiro de 2014 pela Nasa (a agência espacial americana) e pela Agência Japonesa de Exploração Aeroespacial (Jaxa).

“Naquela região, o grande desafio é conseguir estimar a precipitação das chamadas nuvens quentes, que não têm cristais de gelo em seu interior. Elas são comuns na região do semiárido nordestino”, explicou Machado.

Por não abrigarem gelo, a chuva dessas nuvens passa despercebida pelos sensores de micro-ondas que equipam os satélites usados normalmente para medir a precipitação, resultando em dados imprecisos.

As medições de nuvens quentes feitas por radar em Alcântara, comparadas com as medições feitas por satélite, indicaram que os valores de volume de água estavam subestimados em mais de 50%.

Em Fortaleza, onde a coleta foi feita em abril de 2011, foi testado em parceria com a Defesa Civil um sistema de previsão de tempestades em tempo real e de acesso aberto chamado Sistema de Observação de Tempo Severo (SOS Chuva).

“Usamos os dados que estavam sendo coletados pelos radares e os colocamos em tempo real dentro de um sistema de informações geográficas. Dessa forma, é possível fazer previsões para as próximas duas horas. E saber onde chove forte no momento, onde tem relâmpago e como a situação vai se modificar em 20 ou 30 minutos. Também acrescentamos um mapa de alagamento, que permite prever as regiões que podem ficar alagadas caso a água suba um metro, por exemplo”, contou Machado.

A experiência foi tão bem-sucedida, contou o pesquisador, que a equipe decidiu repeti-la nas campanhas realizadas posteriormente. “O SOS Chuva contribui para diminuir a vulnerabilidade da população a eventos extremos do clima, pois oferece informações não apenas para os agentes da Defesa Civil como também para os cidadãos”, disse.

Em junho de 2011 foi realizada a campanha de coleta de dados em Belém, onde os pesquisadores usaram uma rede de instrumentos de GPS para estimar a quantidade de água na atmosfera. Os resultados devem ser publicados em breve. Também foram lançados balões meteorológicos capazes de voar durante 10 horas e coletar dados da atmosfera. “O objetivo era entender o fluxo de vapor d’água que vem do Oceano Atlântico que forma a chuva na Amazônia”, contou Machado.

Entre novembro de 2011 e março de 2012, foi realizada a campanha de São José dos Campos, cujo foco era estudar os relâmpagos e a eletricidade atmosférica. Para isso, foi utilizado um conjunto de redes de detecção de descargas elétricas em parceria com a Agência de Pesquisas Oceânicas e Atmosféricas (NOAA), dos Estados Unidos, e a Agência Europeia de Satélites Meteorológicos (Eumetsat).

“Foram coletados dados para desenvolver os algoritmos dos sensores de descarga elétrica dos satélites geoestacionários de terceira geração, que ainda serão lançados pela NOAA e pela Eumetsat nesta década. Outro objetivo era entender como a nuvem vai se modificando antes que ocorra a primeira descarga elétrica, de forma a prever a ocorrência de raios”, contou Machado.

Em Santa Maria, entre novembro e dezembro de 2012, foram testados, em parceria com pesquisadores argentinos, modelos matemáticos de previsão de eventos extremos. Segundo Machado, a região que abrange o sul do Brasil e o norte da Argentina que ocorrem as tempestades mais severas do mundo.

“Os resultados mostraram que os modelos ainda não são precisos o suficiente para prever com eficácia a ocorrência desses eventos extremos. Em 2017, faremos um novo experimento semelhante, chamado Relâmpago, no norte da Argentina”, contou Machado.

GOAmazon

As duas operações intensivas de coleta de dados realizadas em Manaus – a primeira entre fevereiro e março de 2014 e a segunda entre setembro e outubro do mesmo ano – ainda não haviam ocorrido quando o artigo foi submetido à publicação.

A campanha foi feita no âmbito do projeto Green Ocean Amazon e contou com dois aviões voando em diferentes alturas para acompanhar a pluma de poluição emitida pela região metropolitana de Manaus. O objetivo era avaliar a interação entre os poluentes e os compostos emitidos pela floresta, bem como seu impacto nas propriedades de nuvens (leia mais em http://agencia.fapesp.br/avioes_sobrevoam_a_amazonia_por_quase_200_horas_para_medir_impacto_da_poluicao/20150/). Os dados ainda estão em fase de análise.

Ao comentar as principais diferenças encontradas nas diversas regiões brasileiras, Machado destaca que as regiões Sul e Sudeste são as que apresentam gotas de chuva de tamanhos maiores e uma camada mista, na qual há água no estado líquido e sólido, mais desenvolvida. Essa é, segundo o pesquisador, a principal razão da maior incidência de descargas elétricas nesses locais.

Já as nuvens da Amazônia apresentam a camada de gelo no topo – acima de 20 quilômetros de altura – mais bem desenvolvida que a de outras regiões. As regiões litorâneas, como Alcântara e Fortaleza, apresentam em maior quantidade as chamadas nuvens quentes, nas quais quase não há descargas elétricas.

“Foi o primeiro recenseamento de nuvens feito no Brasil. Essas informações servirão de base para testar e desenvolver modelos capazes de descrever em detalhes a formação de nuvens, com alta resolução espacial e temporal”, concluiu o pesquisador.

Optimism Faces Grave Realities at Climate Talks (New York Times)

WASHINGTON — After more than two decades of trying but failing to forge a global pact to halt climate change, United Nations negotiators gathering in South America this week are expressing a new optimism that they may finally achieve the elusive deal.

Even with a deal to stop the current rate of greenhouse gas emissions, scientists warn, the world will become increasingly unpleasant. Without a deal, they say, the world could eventually become uninhabitable for humans.

For the next two weeks, thousands of diplomats from around the globe will gather in Lima, Peru, for a United Nations summit meeting to draft an agreement intended to stop the global rise of planet-warming greenhouse gases.

The meeting comes just weeks after a landmark announcement by President Obama and President Xi Jinping of China committing the world’s two largest carbon polluters to cuts in their emissions. United Nations negotiators say they believe that advancement could end a longstanding impasse in the climate talks, spurring other countries to sign similar commitments.

Photo

A child walking near her home with a coal-fired power plant in the background in Beijing, China. CreditKevin Frayer/Getty Images 

But while scientists and climate-policy experts welcome the new momentum ahead of the Lima talks, they warn that it now may be impossible to prevent the temperature of the planet’s atmosphere from rising by 3.6 degrees Fahrenheit. According to a large body of scientific research, that is the tipping point at which the world will be locked into a near-term future of drought, food and water shortages, melting ice sheets, shrinking glaciers, rising sea levels and widespread flooding — events that could harm the world’s population and economy.

Recent reports show that there may be no way to prevent the planet’s temperature from rising, given the current level of greenhouse gases already in the atmosphere and the projected rate of emissions expected to continue before any new deal is carried out.

That fact is driving the urgency of the Lima talks, which are expected to produce a draft document, to be made final over the next year and signed by world leaders in Paris in December 2015.

While a breach of the 3.6 degree threshold appears inevitable, scientists say that United Nations negotiators should not give up on their efforts to cut emissions. At stake now, they say, is the difference between a newly unpleasant world and an uninhabitable one.

“I was encouraged by the U.S.-China agreement,” said Michael Oppenheimer, a professor of geosciences and international affairs at Princeton University and a member of the United Nations Intergovernmental Panel on Climate Change, a global body of scientists that produces regular reports on the state of climate science. But he expressed doubts that the threshold rise in global temperature could be prevented.

“What’s already baked in are substantial changes to ecosystems, large-scale transformations,” Mr. Oppenheimer said. He cited losses of coral reef systems and ice sheets, and lowering crop yields.

Still, absent a deal, “Things could get a lot worse,” Mr. Oppenheimer added. Beyond the 3.6 degree threshold, he said, the aggregate cost “to the global economy — rich countries as well as poor countries — rises rapidly.”

Felipe Calderón, the chairman of the Global Commission on the Economy and Climate and former president of Mexico. CreditRichard Drew/Associated Press 

The objective now, negotiators say, is to stave off atmospheric temperature increases of 4 to 10 degrees by the end of the century; at that point, they say, the planet could become increasingly uninhabitable.

Officials at the National Oceanic and Atmospheric Administration are already reporting that 2014 appears likely to be the warmest year on record.

Since 1992, the United Nations has convened an annual climate change summit meeting aimed at forging a deal to curb greenhouse gases, which are produced chiefly by burning coal for electricity and gasoline for transportation. But previous agreements, such as the 1997 Kyoto Protocol, included no requirements that developing nations, such as India and China, cut their emissions. And until now, the United States has never headed into those summit meetings with a domestic climate change policy in place.

This spring, a report by 13 federal agencies concluded that climate change would harm the American economy by increasing food prices, insurance rates and financial volatility. In China, the central government has sought to quell citizen protests related to coal pollution.

In June, Mr. Obama announced a new Environmental Protection Agency rule forcing major emissions cuts from coal-fired power plants. State Department negotiators took the decision to China, hoping to broker a deal for a similar offer of domestic action. That led to November’s joint announcement in Beijing: The United States will cut its emissions up to 28 percent by 2025, while China will decrease its emissions by or before 2030.

“Our sense is that this will resonate in the broader climate community, give momentum to the negotiations and spur countries to come forward with their own targets,” said Todd Stern, Mr. Obama’s lead climate change negotiator. “The two historic antagonists, the biggest players, announcing they’ll work together.”

Other negotiators agree. “The prospects are so much better than they’ve ever been,” said Felipe Calderón, the former president of Mexico and chairman of the Global Commission on the Economy and Climate, a research organization.

The aim of negotiators in Lima is, for the first time, to produce an agreement in which every nation commits to a domestic plan to reduce greenhouse gas emissions, along the model of the United States-China agreement. Negotiators expect that by next March, governments will make announcements similar to those made by the United States and China.

The idea is for each country to cut emissions at a level that it can realistically achieve, but in keeping with domestic political and economic constraints. World leaders would sign a deal in Paris next year committing all those nations to their cuts, including a provision that the nations regularly reconvene to further reduce their emissions.

The problem is that climate experts say it almost certainly will not happen fast enough. A November report by the United Nations Environment Program concluded that in order to avoid the 3.6 degree increase, global emissions must peak within the next 10 years, going down to half of current levels by midcentury.

But the deal being drafted in Lima will not even be enacted until 2020. And the structure of the emerging deal — allowing each country to commit to what it can realistically achieve, given each nation’s domestic politics — means that the initial cuts by countries will not be as stringent as what scientists say is required.

China’s plan calls for its emissions to peak in 2030. Government officials in India, the world’s third-largest carbon polluter, have said they do not expect to see their emissions decline until at least 2040.

While Mr. Obama has committed to United Nations emissions cuts through 2025, there is no way to know if his successor will continue on that path.

That reality is already setting in among low-lying island nations, like the Marshall Islands, where rising seas are soaking coastal soil, killing crops and contaminating fresh water supplies.

“The groundwater that supports our food crops is becoming inundated with salt,” said Tony A. deBrum, foreign minister of the Marshall Islands. “The green is becoming brown.”

Many island nations are looking into buying farmland in other countries to grow food and, eventually, to relocate their populations.

In Lima, those countries are expected to demand that a final deal include aid to help them adapt to the climate impacts that have already arrived.

Mundo deverá quadruplicar energias renováveis até 2050 para conter mudanças climáticas (O Globo)

PUBLICADO 04 NOVEMBRO 2014.

9620

Novo relatório do IPCC afirma também que combustíveis fósseis precisarão ser ‘extintos’ até 2100. Combustíveis fósseis deveriam ser ‘extintos’ até 2100, segundo o IPCC

Copenhague – No capítulo final de uma pesquisa iniciada 13 meses atrás, o Painel Intergovernamental sobre Mudanças Climáticas (IPCC) desfilou uma saraivada de números que refletem o caótico aquecimento global. Segundo o estudo, divulgado ontem em Copenhague, a temperatura média na superfície da Terra aumentou 0,85 grau Celsius entre 1880 e 2012. A concentração de gases-estufa na atmosfera é a maior dos últimos 800 mil anos. As ondas de calor vão se tornar cada vez mais intensas e comuns, especialmente no Hemisfério Norte.

Se o mundo quiser evitar que as mudanças climáticas se tornem irreversíveis, o uso de combustíveis fósseis — o principal motor da economia mundial — deve ser zerado em 2100. Para isso, os países precisam quadruplicar o uso de energias renováveis até 2050. Ignorar este ultimato provocará danos “graves, generalizados e irreversíveis”.

Atualmente, os governos gastam cerca de US$ 600 bilhões por ano no subsídio ao consumo de carvão. Ao mesmo tempo, menos de US$ 400 bilhões são investidos por ano no mundo em políticas de redução de emissões ou em outra forma de enfrentar as mudanças climáticas. Segundo o “New York Times”, esta quantia é menor do que a receita de apenas uma petrolífera americana.

De acordo com o presidente do IPCC, Rajendra Pachauri, os projetos de mitigação contra as mudanças climáticas custariam cerca de 0,06% do PIB mundial por ano até o fim do século. Estima-se que, no mesmo período, a economia internacional crescerá 300%.

— O custo da inércia será horrivelmente maior — assegura Rachauri. — Temos pouco tempo pela frente antes que passe a janela de oportunidade para o aumento de temperatura permanecer abaixo de 2 graus Celsius. Manter o atual modelo de crescimento não é uma opção para nós.

GOLPE NA ECONOMIA

Copresidente de um dos três grupos de trabalho do IPCC, Youba Sokona ressalta que há, no mínimo, 66% de chances de a temperatura global aumentar mais de 2 graus Celsius até 2100, caso a queima de combustíveis fósseis continue no ritmo atual.

— A transição para uma economia com baixo teor de carbono é tecnicamente viável — destaca. — Mas faltam políticas e instituições apropriadas. Quanto mais esperarmos para agir, maior será o custo para mitigação e adaptação.

A liberação de gases-estufa segue em escalada nas últimas décadas. Cerca de metade das emissões de CO2 da era industrial ocorreu nos últimos 40 anos. Com isso, o cenário mais provável é que a temperatura média global ultrapasse os 4 graus Celsius até 2100. Atingir esta marca significa “dificultar a redução da pobreza (…) e corroer a segurança alimentar”, diz o estudo.

Entre 1901 e 2010, o nível do mar aumentou 0,19 centímetro — um valor maior do que nos 2 mil anos anteriores. Se os termômetros continuarem crescendo, em 2050 o gelo do Oceano Ártico terá praticamente desaparecido nos meses de setembro. Até o fim do século, o nível do mar pode aumentar 82 centímetros. Há previsões de grandes enchentes e desaparecimento de países insulares e cidades costeiras.

A mudança do regime de chuvas, a absorção de gases-estufa pelo oceano e o derretimento de geleiras vão afetar a disponibilidade de alimentos para as espécies marinhas. Sua migração também prejudicará a indústria pesqueira.

O calor também afetará o rendimento de safras de trigo, arroz, milho e soja. Estes recursos são a base da economia de países em desenvolvimento. Suas populações, as mais atingidas por eventos extremos, devem migrar para outras regiões. A chegada dos refugiados climáticos aumentará a desigualdade social e a possibilidade de conflitos violentos.

Esta descrição foi atenuada na redação final do relatório. O documento original, editado durante a semana, afirmava que a migração em massa de populações provocaria conflitos violentos “na forma de guerra civil”.

Segundo o Banco Mundial, a comunidade internacional precisará investir entre US$ 1 trilhão e US$ 1,5 trilhão por ano para ajustar sua infraestrutura ao perigo representado pelas mudanças climáticas.

— O impacto das mudanças climáticas será muito diferente em cada país. Por isso é tão difícil estimá-lo — admite a economista Stéphane Hallegatte, coautora do relatório do IPCC. — Eles precisam de dinheiro para desenvolver a tecnologia ecológica, defesa costeira, planos de mitigação e adaptação e gestão de risco de desastres.

Pachauri lembra que as nações mais vulneráveis contribuem pouco para as emissões de gases-estufa. Por isso, atacar o problema torna-se responsabilidade de todos os governos:

— Enfrentar o aquecimento global não será possível se cada agente pensar apenas em seu plano. Precisamos de cooperação entre os países para alcançar nossos objetivos.

FALTA DE ACORDO GLOBAL

O relatório do IPCC, que está em sua quinta edição, deve servir como base para as discussões da Conferência do Clima de Lima, em dezembro deste ano. As esperanças, porém, estão concentradas na edição do ano que vem do encontro, em Paris. Espera-se que este fórum resulte em um acordo global contra as mudanças climáticas. Havia a mesma expectativa em Copenhague, em 2009, quando o debate foi pautado pelo quarto documento do IPCC.

— Tivemos uma conversa extensa há cinco anos, mas, olhando para trás, talvez os líderes mundiais não estivessem tão preparados para discutir o clima — admite o secretário-geral da ONU, Ban ki-Moon. — Eles precisam agir. O tempo não está ao nosso lado.

Não é tão simples assim. O combate às mudanças climáticas é marcado por desentendimentos. Países em desenvolvimento se recusam a aceitar metas para reduzir emissões de CO2 — exigência imposta pelas nações desenvolvidas.

Em setembro, Ban ki-Moon organizou uma Cúpula do Clima na ONU, em uma tentativa de antecipar as discussões previstas para os fóruns ambientais. No encontro foi apresentada a Declaração de Nova York, um documento que propunha a redução pela metade do corte de florestas até 2020 e zerá-lo na década seguinte. Com esta medida, entre 4,5 bilhões e 8,8 bilhões de toneladas de CO2 deixariam de ser liberadas para a atmosfera — o equivalente à remoção de um bilhão de carros das ruas até 2030. Brasil, Índia e China, que estão entre os maiores desmatadores do mundo, recusaram-se a assinar o acordo.

A China, maior poluidora do planeta, comprometeu-se apenas a divulgar quando atingirá o pico de suas emissões — o que deve ocorrer antes de 2030. Os EUA limitam-se a cobrar projetos da potência asiática. A União Europeia e o Brasil estabeleceram metas voluntárias — ou seja, sem valor legal. A Índia, que será a nação mais populosa do mundo daqui a menos de 20 anos, luta para ser definida como país em desenvolvimento, um sinal de que não pretende assumir objetivos.

DISCUSSÕES MADRUGADA ADENTRO

Pachauri, porém, acredita que o novo relatório pode virar o jogo. De acordo com ele, o documento apresentado ontem é “o mais forte e robusto” já produzido pelo IPCC. Para especialistas, o maior objetivo foi cumprido: enfatizar como a ação humana interfere na temperatura do planeta, tese muito contestada poucos anos atrás.

Vice-presidente do IPCC, Suzana Kahn avalia que o relatório final foi mais “claro e objetivo” do que os documentos escritos nos últimos meses pelos grupos de trabalho. Suzana, porém, acredita que os números do IPCC não mudarão facilmente o posicionamento dos governos nas negociações internacionais.

— Os países permanecem com suas posições históricas já consolidadas — afirma Suzana, uma das responsáveis por resumir o relatório original, que tinha 175 páginas, no divulgado ontem, com 40 páginas. — Para fazer isso, foi uma dificuldade. Imagine, então, na negociação propriamente dita. Tanto que, em vez de encerrarmos as discussões na sexta-feira, às 18h, elas só foram fechadas no sábado, às 16h, e precisamos debater todas as madrugadas. Ou seja, tudo foi marcado por pouca disposição de cooperação.

Os climatologistas ressaltam que, mesmo se todas as medidas de mitigação e adaptação forem tomadas, os estragos provocados pelo homem no clima serão visíveis no próximo século, já que as alterações feitas em biomas, geleiras e o acúmulo de carbono nos oceanos não serão remediadas imediatamente. O meio ambiente tem seu próprio tempo. E, para assegurá-lo, o ser humano corre contra o relógio.

Fonte: GVces / O Globo.

U.N. Panel Issues Its Starkest Warning Yet on Global Warming (New York Times)

Machines digging for brown coal in front of a power plant near Grevenbroich, Germany, in April.CreditMartin Meissner/Associated Press

COPENHAGEN — The gathering risks of climate change are so profound that they could stall or even reverse generations of progress against poverty and hunger if greenhouse emissions continue at a runaway pace, according to a major new United Nations report.

Despite growing efforts in many countries to tackle the problem, the global situation is becoming more acute as developing countries join the West in burning huge amounts of fossil fuels, the Intergovernmental Panel on Climate Change said here on Sunday.

Failure to reduce emissions, the group of scientists and other experts found, could threaten society with food shortages, refugee crises, the flooding of major cities and entire island nations, mass extinction of plants and animals, and a climate so drastically altered it might become dangerous for people to work or play outside during the hottest times of the year.

“Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive and irreversible impacts for people and ecosystems,” the report found.

In the starkest language it has ever used, the expert panel made clear how far society remains from having any serious policy to limit global warming.

Doing so would require leaving the vast majority of the world’s reserves of fossil fuels in the ground or, alternatively, developing methods to capture and bury the emissions resulting from their use, the group said.

If governments are to meet their own stated goal of limiting the warming of the planet to no more than 3.6 degrees Fahrenheit, or 2 degrees Celsius, above the preindustrial level, they must restrict emissions from additional fossil-fuel burning to about 1 trillion tons of carbon dioxide, the panel said. At current growth rates, that budget is likely to be exhausted in something like 30 years, possibly less.

Yet energy companies have booked coal and petroleum reserves equal to several times that amount, and they are spending some $600 billion a year to find more. Utilities and oil companies continue to build coal-fired power plants and refineries, and governments are spending another $600 billion or so directly subsidizing the consumption of fossil fuels.

By contrast, the report found, less than $400 billion a year is being spent around the world to reduce emissions or otherwise cope with climate change. That is a small fraction of the revenue spent on fossil fuels — it is less, for example, than the revenue of a single American oil company, ExxonMobil.

The new report comes just a month before international delegates convene in Lima, Peru, to devise a new global agreement to limit emissions, and it makes clear the urgency of their task.

Appearing Sunday morning at a news conference in Copenhagen to unveil the report, the United Nations secretary general, Ban Ki-moon, appealed for strong action in Lima.

“Science has spoken. There is no ambiguity in their message,” Mr. Ban said. “Leaders must act. Time is not on our side.”

Yet there has been no sign that national leaders are willing to discuss allocating the trillion-ton emissions budget among countries, an approach that would confront the problem head-on, but also raise deep questions of fairness. To the contrary, they are moving toward a relatively weak agreement that would essentially let each country decide for itself how much effort to put into limiting global warming, and even that document would not take effect until 2020.

“If they choose not to talk about the carbon budget, they’re choosing not to address the problem of climate change,” said Myles R. Allen, a climate scientist at Oxford University in Britain who helped write the new report. “They might as well not bother to turn up for these meetings.”

The Intergovernmental Panel on Climate Change is a scientific body appointed by the world’s governments to advise them on the causes and effects of global warming, and potential solutions. The group, along with Al Gore, was awarded the Nobel Peace Prize in 2007 for its efforts to call attention to the climate crisis.

The new report is a 175-page synopsis of a much longer series of reports that the panel has issued over the past year. It is the final step in a five-year effort by the body to analyze a vast archive of published climate research.

It is the fifth such report from the group since 1990, each finding greater certainty that the climate is warming and that human activities are the primary cause.

“Human influence has been detected in warming of the atmosphere and the ocean, in changes in the global water cycle, in reductions in snow and ice, and in global mean sea-level rise; and it is extremely likely to have been the dominant cause of the observed warming since the mid-20th century,” the report said.

A core finding of the new report is that climate change is no longer a distant threat, but is being felt all over the world. “It’s here and now,” Rajendra K. Pachauri, the chairman of the panel, said in an interview. “It’s not something in the future.”

The group cited mass die-offs of forests, such as those killed by heat-loving beetles in the American West; the melting of land ice virtually everywhere in the world; an accelerating rise of the seas that is leading to increased coastal flooding; and heat waves that have devastated crops and killed tens of thousands of people.

The report contained the group’s most explicit warning yet about the food supply, saying that climate change had already become a small drag on overall global production, and could become a far larger one if emissions continued unchecked.

A related finding is that climate change poses serious risks to basic human progress, in areas such as alleviating poverty. Under the worst-case scenarios, factors like high food prices and intensified weather disasters would most likely leave poor people worse off. In fact, the report said, that has already happened to a degree.

In Washington, the Obama administration welcomed the report, with the president’s science adviser, John P. Holdren, calling it “yet another wake-up call to the global community that we must act together swiftly and aggressively in order to stem climate change and avoid its worst impacts.”

The administration is pushing for new limits on emissions from American power plants, but faces stiff resistance in Congress and some states.

Michael Oppenheimer, a climate scientist at Princeton University and a principal author of the new report, said that a continuation of the political paralysis on emissions would leave society depending largely on luck.

If the level of greenhouse gases were to continue rising at a rapid pace over the coming decades, severe effects would be avoided only if the climate turned out to be far less sensitive to those gases than most scientists think likely, he said.

“We’ve seen many governments delay and delay and delay on implementing comprehensive emissions cuts,” Dr. Oppenheimer said. “So the need for a lot of luck looms larger and larger. Personally, I think it’s a slim reed to lean on for the fate of the planet.”

Amazônia já está entrando em pane, afirma cientista (Folha de S.Paulo)

Seca no Sudeste pode estar ligada ao desmate e à degradação da floresta

Com 20% da floresta desmatada outros 20% degradados, a floresta amazônica já começa a falhar em seu papel de regulação do clima da América do Sul, diz o biogeoquímico Antonio Nobre, do Inpe (Instituto Nacional de Pesquisas Espaciais).

Veja a matéria na íntegra: http://www1.folha.uol.com.br/fsp/cienciasaude/193261-amazonia-ja-esta-entrando-em-pane-afirma-cientista.shtml

(Rafael Garcia / Folha de S.Paulo)

*   *   *

JC, 5055, 30 de outubro de 2014

Mudanças climáticas provocarão ‘impactos irreversíveis’ nos ecossistemas, dizem cientistas

Grupo que elabora relatório do IPCC destaca que os corais são a maior preocupação ambiental

Vinte e sete ecossistemas podem sofrer impactos “graves, invasivos e irreversíveis”, que atingirão seres humanos e outras espécies, se não forem tomadas providências imediatas contra o aumento de eventos extremos do clima. A maior preocupação são os corais, cuja presença não é muito marcante no Brasil. O tema marcou as discussões de 500 cientistas reunidos nesta quarta-feira em Copenhague, responsáveis por concluir nesta sexta o último relatório do Painel Intergovernamental de Mudanças Climáticas (IPCC).

Veja a matéria completa em: http://oglobo.globo.com/sociedade/ciencia/mudancas-climaticas-provocarao-impactos-irreversiveis-nos-ecossistemas-dizem-cientistas-14404015#ixzz3HdHQtJo2

(Renato Grandelle / O Globo)

Para IPCC, evitar aquecimento de 2°C ainda é possível (Folha de S.Paulo)

Desde segunda-feira, representantes de países debatem em Copenhague a redação final do 4º Relatório Síntese do IPCC

O último documento a ser produzido pelo painel do clima da ONU no ano deve adotar um tom menos pessimista com relação à possibilidade de o planeta evitar um acréscimo de temperatura superior a 2°C neste século, limite considerado perigoso.

Veja a matéria completa: http://www1.folha.uol.com.br/fsp/cienciasaude/193066-para-ipcc-evitar-aquecimento-de-2c-ainda-e-possivel.shtml

(Folha de S.Paulo)

*   *   *

Ano de 2014 pode ser o mais quente da história do planeta

Meses de 2014, à exceção de fevereiro, tiveram as mais altas temperaturas desde 1880, quando começaram os relatórios da Administração Nacional Oceânica e Atmosférica

Quem enfrentou o calor senegalês de janeiro, o inverno de araque em julho e um outubro com cara de verão sentiu na pele os sintomas de um planeta mais aquecido. Não foi uma simples sensação: de fato, é grande a possibilidade de 2014 desbancar 2010 e se tornar o ano mais quente da história, tanto em terra como nas superfícies dos oceanos.

A estimativa é da Administração Nacional Oceânica e Atmosférica (NOAA), agência americana de estudos meteorológicos que computa dados climáticos desde 1880. À exceção de fevereiro, todos os meses do ano até agora bateram recordes como os mais quentes de que se tem notícia.

O conteúdo na íntegra está disponível em: http://zh.clicrbs.com.br/rs/noticias/noticia/2014/10/ano-de-2014-pode-ser-o-mais-quente-da-historia-do-planeta-4631023.html

(Zero Hora)

Climate change in the media (DISCCRS)

DISCCRS News – October 28, 2014

NEWS

Researchers resolve the Karakoram glacier anomaly, a cold case of climate science – Princeton University Press Release – October 22, 2014 – http://www.princeton.edu/main/news/archive/S41/39/84Q12/

    Related: Snowfall less sensitive to warming in Karakoram than in Himalayas due to a unique seasonal cycle – Nature Geoscience – October 12, 2014 – http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2269.html

    Collaboration on this paper with two of the authors is the result of discussions begun at the DISCCRS VII symposium. Lead author Sarah Kapnick, a DISCCRS VII Symposium alum, is a postdoctoral research fellow at Princeton University. Moet Ashfaq is also a DISCCRS VII symposium alum, and is currently a computational climate scientist at the Oak Ridge National Laboratory.

Events that mark Arctic warming – Guardian – October 26, 2014 – http://www.theguardian.com/news/2014/oct/26/weatherwatch-arctic-warming-northwest-passage-siberia

Arctic melt means more severe winters likely – for now – New Scientist – October 27, 2014 – http://www.newscientist.com/article/dn26457-arctic-melt-means-more-severe-winters-likely–for-now.html#.VE7PACiv1sQ

    Related: Cold Winters in Europe, Asia Linked to Sea Ice Decline – Climate Central – October 26, 2014 – http://www.climatecentral.org/news/cold-winters-in-europe-asia-linked-to-arctic-sea-ice-decline-18239

    Related: Global warming has doubled risk of harsh winters in Eurasia, research finds – Guardian – October 26, 2014 – http://www.theguardian.com/environment/2014/oct/26/global-warming-has-doubled-risk-harsh-winters-eurasia-research-finds

UN expert: Keep up hope amid climate change battle – Associated Press – October 27, 2014 – http://bigstory.ap.org/article/ea6b7bb91beb401a85fd8defbcb18826/un-envoy-keep-hope-amid-climate-change-battle

UN climate change draft sees risks of irreversible damage – Reuters – October 26, 2014 – http://www.reuters.com/article/2014/10/26/climatechange-report-idUSL6N0SK0LQ20141026

EU leaders agree to cut greenhouse gas emissions by 40% by 2030 – Guardian – October 24, 2014 – http://www.theguardian.com/world/2014/oct/24/eu-leaders-agree-to-cut-greenhouse-gas-emissions-by-40-by-2030

    Related: EU strikes compromise to set new climate target – Reuters – October 24, 2014 – http://www.reuters.com/article/2014/10/24/us-eu-summit-climatechange-idUSKCN0IB1PB20141024

    Related: EU emissions target isn’t as ambitious as it seems – New Scientist – October 24, 2014 – http://www.newscientist.com/article/dn26446-eu-emissions-target-isnt-as-ambitious-as-it-seems.html#.VE7PCCiv1sQ

    Related: Europe Reaches Climate Deal, Sends Message – Climate Central – October 24, 2014 – http://www.climatecentral.org/news/eu-climate-deal-2030-18228

    Related: EU climate change goal pits green business against industry – Reuters – October 24, 2014 – http://www.reuters.com/article/2014/10/24/eu-summit-climatechange-reaction-pix-tvu-idUSL6N0SJ3CE20141024

Innovations in Energy Storage Provide Boost for Renewables – Yale Environment 360 – October 27, 2014 – http://e360.yale.edu/feature/innovations_in_energy_storage_provide_boost_for_renewables/2820/

Great Barrier Reef protection plan ‘ignores the threat of climate change’ – Guardian – October 27, 2014 – http://www.theguardian.com/environment/2014/oct/27/great-barrier-reef-protection-plan-ignores-threat-climate-change

Recently discovered microbe is key player in climate change – University of Arizona Press Release (via AAAS EurekAlert) – October 22, 2014 – http://www.eurekalert.org/pub_releases/2014-10/uoa-rdm102014.php

FORUM

Rick Piltz Dies at 71; Quit Bush White House Over Climate Policy – New York Times – October 23, 2014 – By Douglas Martin – http://www.nytimes.com/2014/10/24/us/politics/rick-s-piltz-firebrand-on-climate-dies-at-71-.html?_r=0

    Related: Whistleblower Who Exposed White House Tampering with Climate Science Dies – Scientific American Blog – October 22, 2014 – By Paul Thacker – http://blogs.scientificamerican.com/guest-blog/2014/10/22/whistleblower-who-exposed-white-house-tampering-with-climate-science-dies/

U.S. needs to invest in Arctic ships, technology to prepare for climate change: envoy – Reuters – October 21, 2014 – By Andrea Shalal and Ayesha Rascoe – http://www.reuters.com/article/2014/10/21/us-usa-arctic-navy-climatechange-idUSKCN0IA2S520141021

Solving Energy Poverty Need Not Trash the Atmosphere – ClimateWire (via Scientific American) – October 24, 2014 – By Lisa Friedman – http://www.scientificamerican.com/article/solving-energy-poverty-need-not-trash-the-atmosphere/

2014 Arctic sea ice extent – 6th lowest in millennia – Climate Consensus – the 97% blog (Guardian) – October 21, 2014 – By Dana Nuccitelli – http://www.theguardian.com/environment/climate-consensus-97-per-cent/2014/oct/20/2014-arctic-sea-ice-extent-6th-lowest-in-millennia

Climate change has created a new literary genre (Washington Post)

 July 11

Dan Bloom is a climate activist who graduated from Tufts University in 1971 and now blogs about cli-fi issues.

The Jet Star roller coaster is seen in the ocean at dawn as it was left by Hurricane Sandy, in Seaside Heights, New Jersey (Michael Reynolds/EPA)

Is climate change due for an “Uncle Tom’s Cabin” moment? The 1852 bestseller helped transform abolitionism into a mainstream cause. Now, “cli-fi” is trying to do the same for environmentalism.

The emerging genre is a cousin of sci-fi. But its books are set, NPR writes, “in worlds, not unlike our own, where the Earth’s systems are noticeably off-kilter.” And it’s gaining both fans and writers.

The climate-change canon dates back to the 1962 novel ”The Drowned World” by British writer J. G. Ballard. In it, polar ice-caps have melted and global temperatures have soared. Presciently, some coastal American and European cities are under water.

But Ballard’s work didn’t pinpoint humans as the cause of Earth’s precipitous decline. It wasn’t until the mid-2000′s that authors started grappling seriously with our role in impending environmental catastrophe.

In 2004, Michael Crichton released “State of Fear,” a novel about eco-terrorists. Ian McEwan followed up in 2010 with “Solar,” a story about a jaded physicist who tries to solve global warming. And in 2012, Barbara Kingsolver’s “Flight Behavior” gracefully explored how one town is reshaped by a changing ecosystem. As ‘The New York Times wrote in its review of the book:

How do we live, Kingsolver asks, and with what consequences, as we hurtle toward the abyss in these times of epic planetary transformation?

Perhaps the best-known “cli-fi” work is Nathaniel Rich’s “Odds Against Tomorrow,” released in 2013. That book sold more than 100,000 copies and drew major media attention.

In it, a near-future New York is submerged when a Category 3 hurricane hits. As Rich was editing the final proofs, Sandy submerged much of the East Coast, a strange moment of life imitating art.

*   *   *

Rich and others say that fiction can stir emotion and action in a way scientific reports and newscasts don’t.

“You know, scientists and other people are trying to get their message across about various aspects of the climate change issue,” Georgia Institute of Technology professor Judith Curry told NPR. She went on:

“And it seems like fiction is an untapped way of doing this — a way of smuggling some serious topics into the consciousness” of readers who may not be following the science.

That means finding characters or stories that resonate. And it also means getting rid of jargon and cliches. In Rich’s 300-page book, for example, the word “climate change” doesn’t appear once.

“I think the language around climate change is horribly bankrupt and, for the most part, are examples of bad writing, really,” Rich told NPR last year. “I think we need a new type of novel to address a new type of reality … which is that we’re headed toward something terrifying and large and transformative. And it’s the novelist’s job to try to understand, what is that doing to us?”

A growing number of YA books also attack this topic, including Mindy McGinnis’s “Not a Drop to Drink,” Staci Lloyd’s “The Carbon Diaries 2015″ and Joshua David Bellin’s “Survival Colony 9″. Even the post-apocalyptic  “Hunger Games” trilogy hints at a climate-ravaged earth.

Academia has begun paying attention to the trend, too. Several U.S. and British universities are now offering literature courses on cli-fi novels and movies. And the professors who teach those classes say students are moved by the literature they read. According to the ‘New York Times’:

Stephen Siperstein … recalled showing the documentary “Chasing Ice,” about disappearing glaciers, to a class of undergraduates, leaving several of them in tears. Em Jackson talked of leading groups on glacier tours, and the profound effect they had on people. Another student, Shane Hall, noted that people experience the weather, while the notion of climate is a more abstract concept that can often be communicated only through media — from photography to sober scientific articles to futuristic fiction.

“In this sense,” he said, “climate change itself is a form of story we have to tell.”

Índios ajudam a frear aquecimento global, aponta relatório (FSP)

RAFAEL GARCIA

DE SÃO PAULO

24/07/2014 01h43

Florestas em terras indígenas abrigam 37,7 bilhões de toneladas de carbono em todo o mundo. Se fossem destruídas, o CO2 lançado ao ar superaria as emissões globais de veículos durante 29 anos. Por sorte, os índios têm sido mais eficazes do que qualquer outro grupo humano no combate ao desmatamento.

A estimativa está em um relatório divulgado nesta quarta-feira (23) pelas ONGs WRI (World Resources Institute) e RRI (Rights and Resources Initiative). Pesquisadores das duas entidades cruzaram os números de preservação florestal em terras indígenas e de povos tradicionais com dados da FAO (Organização das Nações Unidas para Alimentação e Agricultura) sobre biomassa de florestas. O levantamento foi feito em 2013.

Segundo o relatório, cerca de um oitavo da área de florestas tropicais hoje está dentro dessas áreas. Comparadas com florestas que estão fora da jurisdição de índios, as terras fora delas têm exibido uma taxa de proteção fraca.

Alex Argozino/Editoria de Arte/Folhapress

Em alguns casos, como nas florestas do Yucatán, no México, áreas onde índios têm direito a explorar recursos naturais têm tido menos desmatamento do que reservas ecológicas designadas exclusivamente para proteção.

Na Amazônia brasileira, florestas fora de terras indígenas têm uma taxa de desmatamento 11 vezes maior. Nas matas guatemaltecas que abrigam descendentes dos maias, o grau de proteção é 20 vezes maior, e no resto do Yucatán é 350 vezes maior –índios são praticamente o único tipo de proteção ali.

Parte da razão para isso é que países em desenvolvimento, que abrigam a maior parte das florestas preservadas, muitas vezes não têm recursos para implementar a vigilância contra o desmate ilegal, seja dentro ou fora de unidades de conservação.

Muitas vezes, é melhor reconhecer o direito de comunidades indígenas à terra e lhes dar autonomia para administrar uma área do que transformá-la em reserva ecológica e contratar guardas.

“Quando esses povos têm autorização para criar suas próprias regras e tomar decisões sobre gestão de recursos naturais, são capazes de atingir uma boa governança com bons resultados ambientais”, diz Jenny Springer, diretora de programas globais da RRI. Ela defende a criação de mecanismos internacionais para que tribos indígenas possam ser compensadas por sua contribuição à prevenção de emissão de gases-estufa.

A RRI se concentra em 14 países nos quais avaliou o status legal das terras habitadas por índios. Há algumas condições para que eles sejam capazes de protegê-las.

Na Indonésia, que não dá proteção jurídica à permanência de povos tradicionais em suas áreas, o desmatamento nessas terras ainda é intenso. O país tem licenciado partes de florestas habitadas por comunidades nativas a produtores de dendê.

O Brasil é citado no relatório como bom exemplo, com 31% das terras indígenas em florestas ricas em carbono. O documento não comenta, porém, a proposta de emenda constitucional 215, em debate no Congresso, que reserva ao Legislativo o direito de demarcar terras indígenas, dificultando o processo.