Arquivo da tag: Meteorologia

Pobre previsão do tempo (Folha de S.Paulo)

18/03/2013UncategorizedClima, Enquadramento, Incerteza, jornalismo, Mídia, Mediação tecnológica, Meteorologia, Mudanças climáticas, Previsãorenzotaddei

15/03/2013 – 03h01

Michel Laub

Num artigo publicado na Folha em 2010 (http://goo.gl/fLVDJ), João Moreira Salles discutiu a hipervalorização das humanidades no Brasil, em detrimento de disciplinas como matemática, física e engenharia. Um dos efeitos da distorção, acrescento, é a pouca familiaridade –do público, dos intelectuais, da imprensa– com o discurso técnico e científico. E, por consequência, a docilidade com que são aceitas falácias nessas áreas.

Exemplos: propaganda de governo (números para todos os gostos), dietas da moda (pesquisas com todo tipo de metodologia e patrocínio), tratamentos de saúde (custo-benefício muitas vezes discutível) e até planilhas de futebol (nas quais um volante que só dá passes curtos terá índice de acerto maior que um lançador vertical).

De minha parte, resolvi testar um discurso científico bastante presente no cotidiano: o da meteorologia. Durante 28 dias de janeiro último, anotei erros e acertos do “Jornal do Tempo” (http://jornaldotempo.uol.com.br).

Um trabalho leigo, por certo, e consciente de que o serviço em questão não é representativo do setor no país ou no mundo. A home page do “Jornal do Tempo” apresenta dados que são uma média, um resumo –como na previsão da TV– de registros mais detalhados, inclusive em algumas de suas páginas internas.

Ocorre que médias são a face pública da meteorologia, o tal discurso –em tom seguro e cordial– que nos orienta a escolher a roupa de manhã, a levar ou não o guarda-chuva. E aí, assim como alguma lógica basta para perceber furos em trabalhos estatísticos, não é preciso ser expert para afirmar que há muita imprecisão no ramo.

As temperaturas do meu caderninho quase sempre estiveram dentro dos intervalos previstos na véspera (23 em 28 ocorrências). Comparadas à previsão da semana anterior, o índice cai para 17 em 28. Se botarmos lado a lado o intervalo previsto sete dias antes e o previsto no próprio dia, há diferença em 28 de 28.

Já nas condições atmosféricas, cuja conferência é mais difícil –da minha casa em Pinheiros, não tenho como saber se fui traído por uma garoa enquanto dormia ou algo assim–, houve 15 erros em 28.

São coisas aparentemente sem importância: um ou dois graus a mais, sol durante algumas horas num dia “fechado e chuvoso, com poucas trovoadas”. Mas há reparos objetivos senão aos métodos de medição, ao menos à forma como o resultado é exposto.

Assim, cravar uma temperatura única numa cidade como São Paulo, com seus morros e depressões, paraísos verdes e infernos de concreto em 1,5 milhão de quilômetros quadrados, é inexato por princípio. Igualmente a previsão do tempo numa só frase, que contempla tanto o pé d’água rápido e inofensivo quanto o dilúvio e o caos, dependendo da estrutura do bairro onde se está (“sol, alternando com chuva em forma de pancadas isoladas”).

A questão fica mais complexa quando transcende o território do erro, que é humano e aceitável. E da própria meteorologia, aqui citada apenas como sintoma. A autoridade que emana do discurso científico não se limita a influenciar debates acadêmicos sobre química ou astronomia.

Trata-se, também, de um fenômeno das ciências humanas. Seus desdobramentos políticos, econômicos e morais na sociedade como um todo não são desprezíveis. Foram teorias racialistas que justificaram a escravidão. Foi uma doutrina de incentivo à competição tecnológica que criou as armas nucleares.

No caso do aquecimento global, a grande bandeira científica de hoje, antes de tudo há um imperativo de bom senso: é mais inteligente viver de forma harmônica com a natureza, com menos emissão de carbono, desmatamento e desperdício consumista. Também imagino que previsões de climatologia sejam mais precisas do que, digamos, as da moça que descreve as condições do Sudeste inteiro em dez segundos no “Jornal Nacional”. Mas é fato que a revista “Time” alertou sobre a “nova era glacial” em 1974. E deu uma capa célebre, dez anos depois, sobre a hoje contestada ligação entre infarto e gema de ovo.

Os dois textos reproduziam uma conjectura científica influente à época. É recomendável seguir as que o são hoje –afinal, é o que mais próximo temos de certezas fora do fanatismo religioso ou ideológico. Apenas é bom, como dúvida saudável, em qualquer área de conhecimento vendido como infalível, lembrar da pobre previsão do tempo.

When It Rains These Days, Does It Pour? Has the Weather Become Stormier as the Climate Warms? (Science Daily)

18/03/2013Uncategorizedciência, Clima, Enquadramento, Incerteza, Mediação tecnológica, Meteorologia, Mudanças climáticas, Política, Previsãorenzotaddei

Mar. 17, 2013 — There’s little doubt — among scientists at any rate — that the climate has warmed since people began to release massive amounts greenhouse gases to the atmosphere during the Industrial Revolution.

But ask a scientist if the weather is getting stormier as the climate warms and you’re likely to get a careful response that won’t make for a good quote.

There’s a reason for that.

“Although many people have speculated that the weather will get stormier as the climate warms, nobody has done the quantitative analysis needed to show this is indeed happening,” says Jonathan Katz, PhD, professor of physics at Washington University in St. Louis.

In the March 17 online version ofNature Climate Change, Katz and Thomas Muschinksi, a senior in physics who came to Katz looking for an undergraduate thesis project, describe the results of their analysis of more than 70 years of hourly precipitation data from 13 U.S. sites looking for quantitative evidence of increased storminess.

They found a significant, steady increase in storminess on the Olympic Peninsula in Washington State, which famously suffers from more or less continuous drizzle, a calm climate that lets storm peaks emerge clearly.

“Other sites have always been stormy,” Katz says, “so an increase such as we saw in the Olympic Peninsula data would not have been detectable in their data.”

They may also be getting stormier, he says, but so far they’re doing it under cover.

The difference between wetter and stormier

“We didn’t want to know whether the rainfall had increased or decreased,” Katz says, “but rather whether it was concentrated in violent storm events.”

Studies that look at the largest one-day or few-day precipitation totals recorded in a year, or the number of days in which in which total precipitation is above a threshold, measure whether locations are getting wetter, not whether they’re getting stormier, says Katz.

To get the statistical power to pick up brief downpours rather than total precipitation, Muschinski and Katz needed to find a large, fine-grained dataset.

“So we poked around,” Katz says, “and we found what we were looking for in the National Oceanic and Atmospheric Administration databases.”

NOAA has hourly precipitation data going back to 1940 or even further for many locations in the United States. Muschniski and Katz chose 13 sites that had long runs of data and represented a broad range of climates, from desert to rain forest.

They then tested the hypothesis that storms are becoming more frequent and intense by taking different measurements of the “shape” formed by the data points for each site.

Measuring these “moments” as they’re called, is a statistical test commonly used in science, says Katz, but one that hasn’t been applied to this problem before.

“We found a significant steady increase in stormy activity on the Olympic Peninsula,” Katz says. “We know that is real.”

“We found no evidence for an increase in storminess at the other 12 sites,” he said, “but because their weather is intrinsically stormier, it would be more difficult to detect a trend like that at the Olympic Peninsula even if it were occurring.”

The next step, Katz says, is to look at a much large number of sites that might be regionally averaged to reveal trends too slow to be significant for one site.

“There are larger databases,” he says, “but they’re also harder to sift through. Any one site might have half a million hourly measurements over the period we’re looking at, and to get good results. we have to devise an algorithm tuned to the database to filter out spurious or corrupted data.”

You could call that a rainy-day project.

Journal Reference:

T. Muschinski, J. I. Katz. Trends in hourly rainfall statistics in the United States under a warming climate. Nature Climate Change, 2013; DOI:10.1038/nclimate1828

Bombshell: Recent Warming Is ‘Amazing And Atypical’ And Poised To Destroy Stable Climate That Enabled Civilization (Climate Progress)

13/03/2013UncategorizedClima, Incerteza, Meteorologia, Mudanças climáticas, Previsãorenzotaddei

By Joe Romm on Mar 8, 2013 at 12:44 pm

New Science Study Confirms ‘Hockey Stick’: The Rate Of Warming Since 1900 Is 50 Times Greater Than The Rate Of Cooling In Previous 5000 Years

Temperature change over past 11,300 years (in blue, via Science, 2013) plus projected warming this century on humanity’s current emissions path (in red, via recent literature).

A stable climate enabled the development of modern civilization, global agriculture, and a world that could sustain a vast population. Now, the most comprehensive “Reconstruction of Regional and Global Temperature for the Past 11,300 Years” ever done reveals just how stable the climate has been — and just how destabilizing manmade carbon pollution has been and will continue to be unless we dramatically reverse emissions trends.

Researchers at Oregon State University (OSU) and Harvard University published their findings today in the journal Science. Their funder, the National Science Foundation, explains in a news release:

With data from 73 ice and sediment core monitoring sites around the world, scientists have reconstructed Earth’s temperature history back to the end of the last Ice Age.

The analysis reveals that the planet today is warmer than it’s been during 70 to 80 percent of the last 11,300 years.

… during the last 5,000 years, the Earth on average cooled about 1.3 degrees Fahrenheit–until the last 100 years, when it warmed about 1.3 degrees F.

In short, thanks primarily to carbon pollution, the temperature is changing 50 times faster than it did during the time modern civilization and agriculture developed, a time when humans figured out where the climate conditions — and rivers and sea levels — were most suited for living and farming. We are headed for 7 to 11°F warming this century on our current emissions path — increasing the rate of change 5-fold yet again.

By the second half of this century we will have some 9 billion people, a large fraction of whom will be living in places that simply can’t sustain them — either because it is too hot and/or dry, the land is no longer arable, their glacially fed rivers have dried up, or the seas have risen too much.

We could keep that warming close to 4°F — and avoid the worst consequences — but only with immediate action.

This research vindicates the work of Michael Mann and others showing that recent warming is unprecedented in magnitude, speed, and cause during the past 2000 years — the so-called Hockey Stick — and in fact extends that back to at least 4000 years ago. I should say “vindicates for the umpteenth time” (see “Yet More Studies Back Hockey Stick“).

Lead author Shaun Marcott of OSU told NPR that the paleoclimate data reveal just how unprecedented our current warming is: “It’s really the rates of change here that’s amazing and atypical.” He noted to the AP, “Even in the ice age the global temperature never changed this quickly.”

And the rate of warming is what matters most, as Mann noted in an email to me:

This is an important paper. The key take home conclusion is that the rate and magnitude of recent global warmth appears unprecedented for *at least* the past 4K and the rate *at least* the past 11K. We know that there were periods in the past that were warmer than today, for example the early Cretaceous period 100 million yr ago. The real issue, from a climate change impacts point of view, is the rate of change—because that’s what challenges our adaptive capacity. And this paper suggests that the current rate has no precedent as far back as we can go w/ any confidence—11 kyr arguably, based on this study.

Katharine Hayhoe, an atmospheric scientist at Texas Tech University, told the AP:

We have, through human emissions of carbon dioxide and other heat-trapping gases, indefinitely delayed the onset of the next ice age and are now heading into an unknown future where humans control the thermostat of the planet.

Unfortunately, we have decided to change the setting on the thermostat from “Very Stable, Don’t Adjust” to “Hell and High Water.” It is the single most self-destructive act humanity has ever undertaken, but there is still time to aggressively slash emissions and aim for a setting of “Dangerous, But Probably Not Fatal.”

A Scientist’s Misguided Crusade (N.Y.Times)

12/03/2013UncategorizedCapitalismo, ciência, Cidadania, Clima, discurso ambiental, Economia, Enquadramento, Incerteza, Mídia, Mediação tecnológica, Meteorologia, Mudanças climáticas, Política, Previsãorenzotaddei

OP-ED COLUMNIST

By JOE NOCERA

Published: March 4, 2013

Last Friday, at 3:40 p.m., the State Department released its “Draft Supplemental Environmental Impact Statement” for the highly contentious Keystone XL pipeline, which Canada hopes to build to move its tar sands oil to refineries in the United States. In effect, the statement said there were no environmental impediments that would prevent President Obama from approving the pipeline.

Two hours and 20 minutes later, I received a blast e-mail containing a statement by James Hansen, the head of the Goddard Institute for Space Studies at NASA — i.e., NASA’s chief climate scientist. “Keystone XL, if the public were to allow our well-oiled government to shepherd it into existence, would be the first step down the wrong road, perpetuating our addiction to dirty fossil fuels, moving to ever dirtier ones,” it began. After claiming that the carbon in the tar sands “exceeds that in all oil burned in human history,” Hansen’s statement concluded: “The public must demand that the government begin serving the public’s interest, not the fossil fuel industry’s interest.”

As a private citizen, Hansen, 71, has the same First Amendment rights as everyone else. He can publicly oppose the Keystone XL pipeline if he so chooses, just as he can be as politically active as he wants to be in the anti-Keystone movement, and even be arrested during protests, something he managed to do recently in front of the White House.

But the blast e-mail didn’t come from James Hansen, private citizen. It specifically identified Hansen as the head of the Goddard Institute, and went on to describe him as someone who “has drawn attention to the danger of passing climate tipping points, producing irreversible climate impacts that would yield a different planet from the one on which civilization developed.” All of which made me wonder whether such apocalyptic pronouncements were the sort of statements a government scientist should be making — and whether they were really helping the cause of reversing climate change.

Let’s acknowledge right here that the morphing of scientists into activists is nothing new. Linus Pauling, the great chemist, was a peace activist who pushed hard for a nuclear test ban treaty. Albert Einstein also became a public opponent of nuclear weapons.

It is also important to acknowledge that Hansen has been a crucial figure in developing modern climate science. In 2009, Eileen Claussen, now the president of the Center for Climate and Energy Solutions, told The New Yorker that Hansen was a “heroic” scientist who “faced all kinds of pressures politically.” Today, his body of work is one of the foundations upon which much climate science is built.

Yet what people hear from Hansen today is not so much his science but his broad, unscientific views on, say, the evils of oil companies. In 2008, he wrote a paper, the thesis of which was that runaway climate change would occur when carbon in the atmosphere reached 350 parts per million — a point it had already exceeded — unless it were quickly reduced. There are many climate change experts who disagree with this judgment — who believe that the 350 number is arbitrary and even meaningless. Yet an entire movement,350.org, has been built around Hansen’s line in the sand.

Meanwhile, he has a department to run. For a midlevel scientist at the Goddard Institute, what signal is Hansen sending when he takes the day off to get arrested at the White House? Do his colleagues feel unfettered in their own work? There is, in fact, enormous resentment toward Hansen inside NASA, where many officials feel that their solid, analytical work on climate science is being lost in what many of them describe as “the Hansen sideshow.” His activism is not really doing any favors for the science his own subordinates are producing.

Finally, and most important, Hansen has placed all his credibility on one battle: the fight to persuade President Obama to block the Keystone XL pipeline. It is the wrong place for him to make a stand. Even in the unlikely event the pipeline is stopped, the tar sands oil will still be extracted and shipped. It might be harder to do without a pipeline, but it is already happening. And in the grand scheme, as I’ve written before, the tar sands oil is not a game changer. The oil we import from Venezuela today is dirtier than that from the tar sands. Not that the anti-pipeline activists seem to care.

What is particularly depressing is that Hansen has some genuinely important ideas, starting with placing a graduated carbon tax on fossil fuels. Such a tax would undoubtedly do far more to reduce carbon emissions and save the planet than stopping the Keystone XL pipeline.

A carbon tax might be worth getting arrested over. But by allowing himself to be distracted by Keystone, Hansen is hurting the very cause he claims to care so much about.

Big military guy more scared of climate change than enemy guns (Grist)

11/03/2013UncategorizedClima, Desastre, Enquadramento, Incerteza, Meteorologia, Militares, Mudanças climáticas, Política, Previsão, Visualidaderenzotaddei

By Susie Cagle

11 Mar 2013 6:13 PM

Navy Admiral Samuel J. Locklear III, chief of U.S. Pacific Command, doesn’t look like your usual proponent of climate action. Spencer Ackerman writes at Wired that Locklear “is no smelly hippie,” but the guy does believe there will be terrible security threats on a warming planet, which might make him a smelly hippie in the eyes of many American military boosters.

13-03-11AdmSamuelLocklear — Commander U.S. 7th Fleet

Everyone wants him to be worried about North Korean nukes and Chinese missiles, but in an interview with The Boston Globe, Locklear said that societal upheaval due to climate change “is probably the most likely thing that is going to happen … that will cripple the security environment, probably more likely than the other scenarios we all often talk about.’’

“People are surprised sometimes,” he added, describing the reaction to his assessment. “You have the real potential here in the not-too-distant future of nations displaced by rising sea level. Certainly weather patterns are more severe than they have been in the past. We are on super typhoon 27 or 28 this year in the Western Pacific. The average is about 17.”

Locklear said his Hawaii-based headquarters — which is … responsible for operations from California to India — is working with Asian nations to stockpile supplies in strategic locations and planning a major exercise for May with nearly two dozen countries to practice the “what-ifs.”

Locklear isn’t alone in his climate fears. A recent article by Julia Whitty takes an in-depth look at what the military is doing to deal with climate change. A 2008 report by U.S. intelligence agencieswarned about national security challenges posed by global warming, as have later reports from the Department of Defense and the Joint Chiefs of Staff. New Defense Secretary Chuck Hagel understands the threat, too. People may be surprised sometimes, Adm. Locklear, but they really shouldn’t be!

Will not-a-dirty-hippie Locklear’s words help to further mainstream the idea that climate change is a serious security problem? And what all has the good admiral got planned for this emergency sea-rising drill in May?

Susie Cagle writes and draws news for Grist. She also writes and draws tweets for Twitter.

Terra se aproxima de maiores temperaturas em 11 mil anos; Derretimento no Canadá pode ser irreversível (Folha de São Paulo)

08/03/2013Uncategorizedciência, Clima, Incerteza, Mediação tecnológica, Meteorologia, Mudanças climáticas, Previsãorenzotaddei

JC e-mail 4680, de 08 de Março de 2013.

Salvador Nogueira

Pesquisa reuniu dados de 73 localidades ao redor do mundo para estimar a temperatura global (e local) no período geológico conhecido como Holoceno

Um novo estudo conduzido por pesquisadores da Universidade Estadual do Oregon e da Universidade Harvard, ambas nos EUA, reconstruiu a temperatura média da Terra nos últimos 11,3 mil anos para compará-la aos níveis atuais.

A boa notícia: a Terra hoje está mais fria do que já esteve em sua época mais quente desse período. A má: se os modelos dos climatologistas estiverem certos, atingiremos um novo recorde de calor até o final do século.

O trabalho, publicado na revista “Science”, reuniu dados de 73 localidades ao redor do mundo para estimar a temperatura global (e local) no período geológico conhecido como Holoceno, que começou ao final da última era do gelo, há 11 mil anos.

Depois de consolidar todas as informações, em sua maioria provenientes de amostras de fósseis em sedimentos oceânicos, num único quadro –além de usar técnicas matemáticas para preencher os “buracos” encontrados nas diversas fontes usadas para estimar a temperatura no passado–, os cientistas puderam recriar uma “pequena história da variação climática da Terra”.

Diz-se pequena porque os resultados não permitem enxergar a variação ocorrida em uns poucos anos. É como se cada ponto nos dados representasse a temperatura em um período de 120 anos.

A HISTÓRIA

Os dados confirmam uma velha desconfiança dos cientistas: a de que a Terra passou por um período de aquecimento que começou cerca de 11 mil anos atrás. Em 1,5 mil anos, o planeta esquentou cerca de 0,6ºC e assim se estabilizou, durante cerca de 5.000 anos.

Então, 5,5 mil anos atrás, começou um novo processo de esfriamento –que terminou há 200 anos, com o que ficou conhecido como a “pequena era do gelo”. O planeta ficou 0,7ºC mais frio.

Entram em cena a industrialização acelerada e o século 20. O planeta volta a se esquentar. No momento, ele ainda não bateu o recorde de temperatura visto no início do Holoceno, mas já está mais quente que em 75% dos últimos 11 mil anos.

Assim, o estudo confirma que a temperatura da Terra está subindo em tempos recentes e mostra que a subida é muito mais rápida do que se pensava.

“Essa pesquisa mostra que já experimentamos quase a mesma faixa de mudança de temperatura desde o início da Revolução Industrial que foi vista nos 11 mil anos anteriores da história da Terra –mas essa mudança aconteceu muito mais depressa”, comenta Candace Major, diretor da divisão de Ciências Oceanográficas da Fundação Nacional de Ciência dos EUA, que financiou o estudo.

Por outro lado, a baixa resolução temporal do estudo (é impossível distinguir efeitos de poucos anos) dificulta a comparação com o atual fenômeno de aquecimento.

Para a mudança climática atual se tornar relevante na escala de tempo analisada pelo modelo de reconstrução dos últimos 11 mil anos, ela precisa continuar no próximo século. Segundo os modelos do IPCC (Painel Intergovernamental para Mudança Climática), da ONU, é isso que vai acontecer.

Contudo, ainda há incertezas sobre a magnitude do fenômeno. De toda forma, mesmo pelas estimativas mais otimistas, quando chegarmos a 2100, se nada for feito, provavelmente estaremos vivendo o período mais quente dos últimos 11 mil anos.

* * *

JC e-mail 4680, de 08 de Março de 2013.

via Reuters

As geleiras canadenses, terceiro maior depósito de gelo depois da Antártida e da Groenlândia, podem estar sofrendo um derretimento sem volta que deve aumentar o nível do mar, afirmaram cientistas

Cerca de 20% das geleiras no norte do Canadá podem desaparecer até o fim do século 21, num derretimento que pode acrescentar 3,5 cm ao nível do mar.

Segundo artigo na revista “Geophysical Research Letters”, o derretimento de geleiras brancas exporia a tundra escura, que tende a absorver mais calor e acelerar o derretimento.

A ONU estima um aumento do nível do mar entre 18 cm e 59 cm neste século ou mais se a cobertura de gelo da Antártida e da Groenlândia começar a derreter mais rápido.

A projeção de perda de 20% do volume de gelo no Canadá se baseou em um cenário com aumento de temperatura médio de 3ºC neste século e de 8ºC no Ártico canadense, dentro das previsões da ONU.

The Crisis in Climate-Change Coverage (Truth Out)

03/03/2013UncategorizedClima, jornalismo, Mídia, Meteorologia, Mudanças climáticas, Opinião pública, Políticarenzotaddei

Sunday, 03 March 2013 07:23

By Josh Stearns, Free Press

Climate activist Bill McKibben speaking at the San Francisco Bay Area’s Moving Planet rally. (Photo: 350.org / flickr)

Fifty-thousand people recently marched in Washington, D.C., calling on President Obama to fulfill his recent promises to take immediate and meaningful action to address the looming climate crisis.

And just days before, a group of environmental journalists, scientists and activists came together in a Web chat to discuss the state of climate-change coverage in America.

The event, organized by Free Press andOrion Magazine, featured Kate Sheppard of Mother Jones; Bill McKibben, author and 350.org founder; Wen Stephenson, writer and climate activist; M. Sanjayan, CBS News contributor and Nature Conservancy scientist; Thomas Lovejoy, chief biologist at the Heinz Center and creator of the PBS show Nature; and reporter Susie Cagle of Grist.org.

Here’s what they had to say. (You can listen to the entire discussion here.)

Structure Versus Culture

A complex mix of structural and cultural factors has affected climate-change coverage in the U.S. The forces that shape U.S. media have not been kind to environmental reporting. Years of media consolidation have led to dramatic layoffs in commercial newsrooms, and environment and science desks are often the first to go. In addition, M. Sanjayan noted that media consolidation has had an echo-chamber effect: All climate stories sound the same and they lack depth, specificity and connection to place.

The U.S. also under-funds noncommercial alternatives, like public media, where climate-change reporting should thrive. The best environmental writing is happening at the margins of our media at longtime nonprofit magazines and new online startups. In contrast, mainstream outlets have tended to legitimize climate-change deniers in the face of widespread scientific consensus about the effects of global warming.

Wen Stephenson argued that journalists have been reticent to raise the alarm about climate change. “The mainstream media has failed to cover the climate crisis as a crisis,” he said.

Empathy Versus Objectivity

A repeated theme of the conversation was the line between advocacy and journalism. There was disagreement about where the line should fall. Kate Sheppard said she was disappointed that coverage of the BP oil spill didn’t inspire more sustained activism on climate change, but noted that it wasn’t her job to organize, only to inform.

Stephenson, on the other hand, argued that when it comes to climate change, journalists need to find their moral bearings. Acknowledging the limits of objectivity, Stephenson discussed the value of empathy and the need to understand the true human and natural stakes of this debate.

Telling a More Human Story

The panelists agreed that climate-change reporting needs to get personal. Journalists need to better connect climate change to people’s lives, their homes, their families and their everyday concerns. Susie Cagle said that when she reports on climate change she does so through the lens of cities, rivers and food.

Bill McKibben pointed to the way 350.org activists have shifted the narrative — literally putting their bodies on the line by holding protests and other events around the globe. McKibben also noted the importance of people making their own media — with photos, videos and blogs —especially when there are fewer and fewer local media outlets willing to take on the work.

Sanjayan said we need a better way to frame climate-change reporting. The Keystone XL Pipeline story has gained so much traction in part because there is a clear bad guy, a clear target and clear actions people can take. Those elements aren’t always present, so journalists need to find different ways to reach their audiences. We need to be aware of who is telling the story. Sanjayan noted that all too often, climate-change reporting is too U.S.-centric and doesn’t tell the full global story.

Quality and Quantity Versus Reach and Impact

Thirty-two years ago television offered nothing of substance about the natural world or the threats it faced. This was the inspiration for Thomas Lovejoy, the scientist who coined the term “biodiversity,” to pitch a new kind of show to New York public TV station WNET.

Since PBS’ Nature first aired, a lot has changed. Now, Sheppard said, there is a ton of great environmental reporting, but it’s not always easy to find and it’s not always seen by the people who need to see it. One way to foster better coverage, Sheppard said, is to support what’s already out there by sharing it, funding it and subscribing to those doing it.

Panelists acknowledged that many publications — like this Web chat itself — end up speaking to the choir when we desperately need to get beyond it. For Sheppard, one way of doing that is through journalism collaborations that help get content out to new audiences and on different platforms.

For Cagle, the platform piece is key. She talked about the need to get beyond the “wall of text” and tell more immersive stories about climate. For her, the use of audio and illustrations helps bring readers into the story. “Art can make stories more accessible and personal,” said Cagle.

Sanjayan discussed the potential for cable TV to be a powerful messenger. For example, he is working on an in-depth series for Showtime on climate change.

Next Steps

The discussion offered few cut-and-dry prescriptions for concrete changes that need to happen to embolden and expand climate coverage. Panelists agreed that we need a journalism of solutions, not just a journalism of problems. For newsrooms and journalists, the first step is to begin to understand the scope and scale of this crisis, and write as if your life depended on it.

Why Are Environmentalists Taking Anti-Science Positions? (Yale e360)

19/02/2013Uncategorizedambientalismo, ciência, Clima, discurso ambiental, Enquadramento, Incerteza, Meteorologia, Mudanças climáticas, Opinião pública, Política, Previsãorenzotaddei

22 OCT 2012

On issues ranging from genetically modified crops to nuclear power, environmentalists are increasingly refusing to listen to scientific arguments that challenge standard green positions. This approach risks weakening the environmental movement and empowering climate contrarians.

By Fred Pearce

From Rachel Carson’s Silent Spring to James Hansen’s modern-day tales of climate apocalypse, environmentalists have long looked to good science and good scientists and embraced their findings. Often we have had to run hard to keep up with the crescendo of warnings coming out of academia about the perils facing the world. A generation ago, biologist Paul Ehrlich’sThe Population Bomb and systems analysts Dennis and Donella Meadows’The Limits to Growth shocked us with their stark visions of where the world was headed. No wide-eyed greenie had predicted the opening of an ozone hole before the pipe-smoking boffins of the British Antarctic Survey spotted it when looking skyward back in 1985. On issues ranging from ocean acidification and tipping points in the Arctic to the dangers of nanotechnology, the scientists have always gotten there first — and the environmentalists have followed.

And yet, recently, the environment movement seems to have been turning up on the wrong side of the scientific argument. We have been making claims that simply do not stand up. We are accused of being anti-science — and not without reason. A few, even close friends, have begun to compare this casual contempt for science with the tactics of climate contrarians.

That should hurt.

Three current issues suggest that the risks of myopic adherence to ideology over rational debate are real: genetically modified (GM) crops, nuclear power, and shale gas development. The conventional green position is that we should be opposed to all three. Yet the voices of those with genuine environmental credentials, but who take a different view, are being drowned out by sometimes abusive and irrational argument.

In each instance, the issue is not so much which side environmentalists should be on, but rather the mind-set behind those positions and the tactics adopted to make the case. The wider political danger is that by taking anti-scientific positions, environmentalists end up helping the anti-environmental sirens of the new right.

The issue is not which side environmentalists should be on, but rather the mind-set behind their positions.

Most major environmental groups — from Friends of the Earth to Greenpeace to the Sierra Club — want a ban or moratorium on GM crops, especially for food. They fear the toxicity of these “Frankenfoods,” are concerned the introduced genes will pollute wild strains of the crops, and worry that GM seeds are a weapon in the takeover of the world’s food supply by agribusiness.

For myself, I am deeply concerned about the power of business over the world’s seeds and food supply. But GM crops are an insignificant part of that control, which is based on money and control of trading networks. Clearly there are issues about gene pollution, though research suggesting there is a problem is still very thin. Let’s do the research, rather than trash the test fields, which has been the default response of groups such as Greenpeace, particularly in my home country of Britain.

As for the Frankenfoods argument, the evidence is just not there. As the British former campaigner against GMs, Mark Lynas, points out: “Hundreds of millions of people have eaten GM-originated food without a single substantiated case of any harm done whatsoever.”

The most recent claim, published in September in the journal Food and Chemical Toxicology, that GM corn can produced tumors in rats, has been attacked as flawed in execution and conclusion by a wide range of experts with no axe to grind. In any event, the controversial study was primarily about the potential impact of Roundup, a herbicide widely used with GM corn, and not the GM technology itself.

Nonetheless, the reaction of some in the environment community to the reasoned critical responses of scientists to the paper has been to claim a global conspiracy among researchers to hide the terrible truth. One scientist was dismissed on the Web site GM Watch for being “a longtime member of the European Food Safety Authority, i.e. the very body that approved the GM corn in question.” That’s like dismissing the findings of a climate scientist because he sits on the Intergovernmental Panel on Climate Change — the “very body” that warned us about climate change. See what I mean about aping the worst and most hysterical tactics of the climate contrarians?

Stewart Brand wrote in his 2009 book Whole Earth Discipline: “I dare say the environmental movement has done more harm with its opposition to genetic engineering than any other thing we’ve been wrong about.” He will see nods of ascent from members of a nascent “green genes” movement — among them environmentalist scientists, such as Pamela Ronald of the University of California at Davis — who say GM crops can advance the cause of sustainable agriculture by improving resilience to changing climate and reducing applications of agrochemicals.

Yet such people are routinely condemned as apologists for an industrial conspiracy to poison the world. Thus, Greenpeace in East Asia claims that children eating nutrient-fortified GM “golden rice” are being used as “guinea pigs.” And its UK Web site’s introduction to its global campaigns says, “The introduction of genetically modified food and crops has been a disaster, posing a serious threat to biodiversity and our own health.” Where, ask their critics, is the evidence for such claims?

The problem is the same in the energy debate. Many environmentalists who argue, as I do, that climate change is probably the big overarching issue facing humanity in the 21st century, nonetheless often refuse to recognize that nuclear power could have a role in saving us from the worst.

For environmentalists to fan the flames of fear of nuclear power seems reckless and anti-scientific.

Nuclear power is the only large-scale source of low-carbon electricity that is fully developed and ready for major expansion.

Yes, we need to expand renewables as fast as we can. Yes, we need to reduce further the already small risks of nuclear accidents and of leakage of fissile material into weapons manufacturing. But as George Monbiot, Britain’s most prominent environment columnist, puts it: “To abandon our primary current source of low carbon energy during a climate change emergency is madness.”

Monbiot attacks the gratuitous misrepresentation of the risks of radiation from nuclear plants. It is widely suggested, on the basis of a thoroughly discredited piece of Russian head-counting, that up to a million people were killed by the Chernobyl nuclear accident in 1986. In fact, it is far from clear that many people at all — beyond the 28 workers who received fatal doses while trying to douse the flames at the stricken reactor — actually died from Chernobyl radiation. Certainly, the death toll was nothing remotely on the scale claimed.

“We have a moral duty,” Monbiot says, “not to spread unnecessary and unfounded fears. If we persuade people that they or their children are likely to suffer from horrible and dangerous health problems, and if these fears are baseless, we cause great distress and anxiety, needlessly damaging the quality of people’s lives.”

Many people have a visceral fear of nuclear power and its invisible radiation. But for environmentalists to fan the flames — especially when it gets in the way of fighting a far more real threat, from climate change — seems reckless, anti-scientific and deeply damaging to the world’s climate future.

One sure result of Germany deciding to abandon nuclear power in the wake of last year’s Fukushima nuclear accident (calamitous, but any death toll will be tiny compared to that from the tsunami that caused it) will be rising carbon emissions from a revived coal industry. By one estimate, the end of nuclear power in Germany will result in an extra 300 million tons of carbon dioxide reaching the atmosphere between now and 2020 — more than the annual emissions of Italy and Spain combined.

Last, let’s look at the latest source of green angst: shale gas and the drilling technique of hydraulic fracturing, or fracking, used to extract it. There are probably good reasons for not developing shale gas in many places. Its extraction can pollute water and cause minor earth tremors, for instance. But at root this is an argument about carbon — a genuinely double-edged issue that needs debating. For there is a good environmental case to be made that shale gas, like nuclear energy, can be part of the solution to climate change. That case should be heard and not shouted down.

Opponents of shale gas rightly say it is a carbon-based fossil fuel. But it is a much less dangerous fossil fuel than coal. Carbon emissions from burning natural gas are roughly half those from burning coal. A switch from coal to shale gas is the main reason why, in 2011, U.S. CO2 emissions fell by almost 2 percent.

Many environmentalists are imbued with a sense of their own exceptionalism and original virtue.

We cannot ignore that. With coal’s share of the world’s energy supply rising from 25 to 30 percent in the past half decade, a good argument can be made that a dash to exploit cheap shale gas and undercut this surge in coal would do more to cut carbon emissions than almost anything else. The noted environmental economist Dieter Helm of the University of Oxford argues just this in a new book, The Carbon Crunch, out this month.

But this is an unpopular argument. Carl Pope, executive director of the Sierra Club, was pilloried by activists for making the case that gas could be a “bridge fuel” to a low-carbon future. And when he stepped down, his successor condemned him for taking cash from the gas industry to fund the Sierra Club’s Beyond Coal campaign. Pope was probably wrong to take donations of that type, though some environment groups do such things all the time. But his real crime to those in the green movement seems to have been to side with the gas lobby at all.

Many environmentalists are imbued with a sense of their own exceptionalism and original virtue. But we have been dangerously wrong before. When Rachel Carson’s sound case against the mass application of DDT as an agricultural pesticide morphed into blanket opposition to much smaller indoor applications to fight malaria, it arguably resulted in millions of deaths as the diseases resurged.

And more recently, remember the confusion over biofuels? They were a new green energy source we could all support. I remember, when the biofuels craze began about 2005, I reported on a few voices urging caution. They warned that the huge land take of crops like corn and sugar cane for biofuels might threaten food supplies; that the crops would add to the destruction of rainforests; and that the carbon gains were often small to non-existent. But Friends of the Earth and others trashed them as traitors to the cause of green energy.
Well, today most greens are against most biofuels. Not least Friends of the Earth, which calls them a “big green con.” In fact, we may have swung too far in the other direction, undermining research into second-generation biofuels that could be both land- and carbon-efficient.

We don’t have to be slaves to science. There is plenty of room for raising questions about ethics and priorities that challenge the world view of the average lab grunt. And we should blow the whistle on bad science. But to indulge in hysterical attacks on any new technology that does not excite our prejudices, or to accuse genuine researchers of being part of a global conspiracy, is dishonest and self-defeating.

We environmentalists should learn to be more humble about our policy prescriptions, more willing to hear competing arguments, and less keen to engage in hectoring and bullying.

Forecasting Climate With A Chance Of Backlash (NPR)

19/02/2013UncategorizedClima, Incerteza, jornalismo, Mídia, Meteorologia, Mudanças climáticas, Previsãorenzotaddei

by JENNIFER LUDDEN

February 19, 2013 3:14 AM

Listen to the Story

When it comes to climate change, Americans place great trust in their local TV weathercaster, which has led climate experts to see huge potential for public education.

The only problem? Polls show most weather presenters don’t know much about climate science, and many who do are fearful of talking about something so polarizing.

In fact, if you have heard a weathercaster speak on climate change, it’s likely been to deny it. John Coleman in San Diego and Anthony Watts of Watts Up With That? are among a group of vocal die-hards, cranking out blog posts and videos countering climate science. But even many meteorologists who don’t think it’s all a hoax still profoundly distrust climate models.

“They get reminded each and every day anytime their models don’t prove to be correct,” says Ed Maibach, who directs the Center for Climate Change Communication at George Mason University, and has carried out several surveys of TV weathercasters. “For them, the whole notion of projecting what the climate will be 30, 50, a hundred years from now, they’ve got a fairly high degree of skepticism.”

And yet, Maibach has found that many meteorologists would like to learn more and would like to educate their viewers. A few years back, he hatched a plan and found a willing partner in an unlikely place.

Prepared For Backlash

“I loved it. That’s exactly what I wanted to do,” says Jim Gandy, chief meteorologist at WLTX in Columbia, S.C.

Gandy had actually begun reading up on climate change several years earlier, when — to his surprise — a couple of geology professors at a party asked whether he thought global warming was real. Gandy was disturbed by what he learned and was game to go on air with it, even in what he calls a “dark red” state with a lot of “resistance” to the idea of climate change.

“We talked about it at length,” he says, “and we were prepared for a backlash.”

Researchers at George Mason University, with the help of Climate Central, tracked down information specific to Columbia, something many local meteorologists, with multiple weather reports a day, simply have no time to do. They also created graphics for Gandy to use whenever the local weather gave him a peg. And Gandy’s local TV station gave him something precious: 90 seconds of air time in the evening newscast.

The segment was called “Climate Matters,” and Gandy kicked it off in late July 2010. He dove in deep, packing his limited time with tidbits usually buried in scientific papers. One segment looked at what Columbia’s summer temperatures are projected to be in 40 years. Another explained how scientists can track man-made global warming, since carbon dioxide from fossil fuels has a specific chemical footprint.

Gandy also made the issue personal for viewers, reporting on how climate change will make pollen and poison ivy grow faster and more potent. He says people stopped him on the street about that.

And the backlash? There were a few cranky comments. “To my knowledge,” Gandy says, “there was at least one phone call from someone saying they needed to fire me.” But generally, the series went over well.

Better Informed Viewers

Meanwhile, researcher Ed Maibach polled people before Climate Matters began, then again a year into it. He says compared with viewers of other local stations, those who watched Jim Gandy gained a more scientifically grounded understanding of climate change, from understanding that it’s largely caused by humans, that it’s happening here and now and that it’s harmful.

“All of this is the kind of information that will help people, and help communities, make better decisions about how to adapt to a changing climate,” Maibach says.

Maibach hopes to expand the experiment, eventually making localized climate research and graphs available to meteorologists across the country. And there are other efforts to help weather forecasters become climate educators.

Last March, longtime Minnesota meteorologist Paul Douglas, founder of WeatherNationTV, posted an impassioned letter online urging his fellow Republicans to acknowledge that climate change is real.

“Other meteorologists actually emailed me and said, ‘Thanks for giving voice to something I’ve been thinking but was too afraid to say publicly,’ ” he says.

Douglas is part of a group pushing to tighten certification standards for meteorologists.

“If you’re going to talk about climate science on the air,” he says, you would “need to learn about the real science, and not get it off a talk show radio program or a website.”

After all, both he and Gandy say it’s becoming harder to separate weather from climate. That means TV weathercasters will be busier, and more closely followed, than ever.

Richard A. Muller: The Conversion of a Climate-Change Skeptic (N.Y.Times)

18/02/2013Uncategorizedciência, Clima, Enquadramento, Incerteza, Mediação tecnológica, Meteorologia, Mudanças climáticas, Política, Previsãorenzotaddei

OP-ED CONTRIBUTOR

By RICHARD A. MULLER

Published: July 28, 2012

Berkeley, Calif.

CALL me a converted skeptic. Three years ago I identified problems in previous climate studies that, in my mind, threw doubt on the very existence of global warming. Last year, following an intensive research effort involving a dozen scientists, I concluded that global warming was real and that the prior estimates of the rate of warming were correct. I’m now going a step further: Humans are almost entirely the cause.

My total turnaround, in such a short time, is the result of careful and objective analysis by the Berkeley Earth Surface Temperature project, which I founded with my daughter Elizabeth. Our results show that the average temperature of the earth’s land has risen by two and a half degrees Fahrenheit over the past 250 years, including an increase of one and a half degrees over the most recent 50 years. Moreover, it appears likely that essentially all of this increase results from the human emission of greenhouse gases.

These findings are stronger than those of the Intergovernmental Panel on Climate Change, the United Nations group that defines the scientific and diplomatic consensus on global warming. In its 2007 report, the I.P.C.C. concluded only that most of the warming of the prior 50 years could be attributed to humans. It was possible, according to the I.P.C.C. consensus statement, that the warming before 1956 could be because of changes in solar activity, and that even a substantial part of the more recent warming could be natural.

Our Berkeley Earth approach used sophisticated statistical methods developed largely by our lead scientist, Robert Rohde, which allowed us to determine earth land temperature much further back in time. We carefully studied issues raised by skeptics: biases from urban heating (we duplicated our results using rural data alone), from data selection (prior groups selected fewer than 20 percent of the available temperature stations; we used virtually 100 percent), from poor station quality (we separately analyzed good stations and poor ones) and from human intervention and data adjustment (our work is completely automated and hands-off). In our papers we demonstrate that none of these potentially troublesome effects unduly biased our conclusions.

The historic temperature pattern we observed has abrupt dips that match the emissions of known explosive volcanic eruptions; the particulates from such events reflect sunlight, make for beautiful sunsets and cool the earth’s surface for a few years. There are small, rapid variations attributable to El Niño and other ocean currents such as the Gulf Stream; because of such oscillations, the “flattening” of the recent temperature rise that some people claim is not, in our view, statistically significant. What has caused the gradual but systematic rise of two and a half degrees? We tried fitting the shape to simple math functions (exponentials, polynomials), to solar activity and even to rising functions like world population. By far the best match was to the record of atmospheric carbon dioxide, measured from atmospheric samples and air trapped in polar ice.

Just as important, our record is long enough that we could search for the fingerprint of solar variability, based on the historical record of sunspots. That fingerprint is absent. Although the I.P.C.C. allowed for the possibility that variations in sunlight could have ended the “Little Ice Age,” a period of cooling from the 14th century to about 1850, our data argues strongly that the temperature rise of the past 250 years cannot be attributed to solar changes. This conclusion is, in retrospect, not too surprising; we’ve learned from satellite measurements that solar activity changes the brightness of the sun very little.

How definite is the attribution to humans? The carbon dioxide curve gives a better match than anything else we’ve tried. Its magnitude is consistent with the calculated greenhouse effect — extra warming from trapped heat radiation. These facts don’t prove causality and they shouldn’t end skepticism, but they raise the bar: to be considered seriously, an alternative explanation must match the data at least as well as carbon dioxide does. Adding methane, a second greenhouse gas, to our analysis doesn’t change the results. Moreover, our analysis does not depend on large, complex global climate models, the huge computer programs that are notorious for their hidden assumptions and adjustable parameters. Our result is based simply on the close agreement between the shape of the observed temperature rise and the known greenhouse gas increase.

It’s a scientist’s duty to be properly skeptical. I still find that much, if not most, of what is attributed to climate change is speculative, exaggerated or just plain wrong. I’ve analyzed some of the most alarmist claims, and my skepticism about them hasn’t changed.

Hurricane Katrina cannot be attributed to global warming. The number of hurricanes hitting the United States has been going down, not up; likewise for intense tornadoes. Polar bears aren’t dying from receding ice, and the Himalayan glaciers aren’t going to melt by 2035. And it’s possible that we are currently no warmer than we were a thousand years ago, during the “Medieval Warm Period” or “Medieval Optimum,” an interval of warm conditions known from historical records and indirect evidence like tree rings. And the recent warm spell in the United States happens to be more than offset by cooling elsewhere in the world, so its link to “global” warming is weaker than tenuous.

The careful analysis by our team is laid out in five scientific papers now online at BerkeleyEarth.org. That site also shows our chart of temperature from 1753 to the present, with its clear fingerprint of volcanoes and carbon dioxide, but containing no component that matches solar activity. Four of our papers have undergone extensive scrutiny by the scientific community, and the newest, a paper with the analysis of the human component, is now posted, along with the data and computer programs used. Such transparency is the heart of the scientific method; if you find our conclusions implausible, tell us of any errors of data or analysis.

What about the future? As carbon dioxide emissions increase, the temperature should continue to rise. I expect the rate of warming to proceed at a steady pace, about one and a half degrees over land in the next 50 years, less if the oceans are included. But if China continues its rapid economic growth (it has averaged 10 percent per year over the last 20 years) and its vast use of coal (it typically adds one new gigawatt per month), then that same warming could take place in less than 20 years.

Science is that narrow realm of knowledge that, in principle, is universally accepted. I embarked on this analysis to answer questions that, to my mind, had not been answered. I hope that the Berkeley Earth analysis will help settle the scientific debate regarding global warming and its human causes. Then comes the difficult part: agreeing across the political and diplomatic spectrum about what can and should be done.

Richard A. Muller, a professor of physics at the University of California, Berkeley, and a former MacArthur Foundation fellow, is the author, most recently, of “Energy for Future Presidents: The Science Behind the Headlines.”

New Research Shows Complexity of Global Warming (Science Daily)

31/01/2013UncategorizedClima, História, Incerteza, Matemática, Mediação tecnológica, Meteorologia, Mudanças climáticas, Previsãorenzotaddei

Jan. 30, 2013 — Global warming from greenhouse gases affects rainfall patterns in the world differently than that from solar heating, according to a study by an international team of scientists in the January 31 issue of Nature. Using computer model simulations, the scientists, led by Jian Liu (Chinese Academy of Sciences) and Bin Wang (International Pacific Research Center, University of Hawaii at Manoa), showed that global rainfall has increased less over the present-day warming period than during the Medieval Warm Period, even though temperatures are higher today than they were then.

Clouds over the Pacific Ocean. (Credit: Shang-Ping Xie)

The team examined global precipitation changes over the last millennium and future projection to the end of 21st century, comparing natural changes from solar heating and volcanism with changes from human-made greenhouse gas emissions. Using an atmosphere-ocean coupled climate model that simulates realistically both past and present-day climate conditions, the scientists found that for every degree rise in global temperature, the global rainfall rate since the Industrial Revolution has increased less by about 40% than during past warming phases of Earth.

Why does warming from solar heating and from greenhouse gases have such different effects on global precipitation?

“Our climate model simulations show that this difference results from different sea surface temperature patterns. When warming is due to increased greenhouse gases, the gradient of sea surface temperature (SST) across the tropical Pacific weakens, but when it is due to increased solar radiation, the gradient increases. For the same average global surface temperature increase, the weaker SST gradient produces less rainfall, especially over tropical land,” says co-author Bin Wang, professor of meteorology.

But why does warming from greenhouse gases and from solar heating affect the tropical Pacific SST gradient differently?

“Adding long-wave absorbers, that is heat-trapping greenhouse gases, to the atmosphere decreases the usual temperature difference between the surface and the top of the atmosphere, making the atmosphere more stable,” explains lead-author Jian Liu. “The increased atmospheric stability weakens the trade winds, resulting in stronger warming in the eastern than the western Pacific, thus reducing the usual SST gradient — a situation similar to El Niño.”

Solar radiation, on the other hand, heats Earth’s surface, increasing the usual temperature difference between the surface and the top of the atmosphere without weakening the trade winds. The result is that heating warms the western Pacific, while the eastern Pacific remains cool from the usual ocean upwelling.

“While during past global warming from solar heating the steeper tropical east-west SST pattern has won out, we suggest that with future warming from greenhouse gases, the weaker gradient and smaller increase in yearly rainfall rate will win out,” concludes Wang.

Journal Reference:

Jian Liu, Bin Wang, Mark A. Cane, So-Young Yim, June-Yi Lee. Divergent global precipitation changes induced by natural versus anthropogenic forcing. Nature, 2013; 493 (7434): 656 DOI: 10.1038/nature11784

Understanding the Historical Probability of Drought (Science Daily)

31/01/2013UncategorizedClima, Desastre, Enquadramento, Estatística, Incerteza, Matemática, Mediação tecnológica, Memória, Meteorologia, Mudanças climáticas, Previsão, Probabilidades, Secarenzotaddei

Jan. 30, 2013 — Droughts can severely limit crop growth, causing yearly losses of around $8 billion in the United States. But it may be possible to minimize those losses if farmers can synchronize the growth of crops with periods of time when drought is less likely to occur. Researchers from Oklahoma State University are working to create a reliable “calendar” of seasonal drought patterns that could help farmers optimize crop production by avoiding days prone to drought.

Historical probabilities of drought, which can point to days on which crop water stress is likely, are often calculated using atmospheric data such as rainfall and temperatures. However, those measurements do not consider the soil properties of individual fields or sites.

“Atmospheric variables do not take into account soil moisture,” explains Tyson Ochsner, lead author of the study. “And soil moisture can provide an important buffer against short-term precipitation deficits.”

In an attempt to more accurately assess drought probabilities, Ochsner and co-authors, Guilherme Torres and Romulo Lollato, used 15 years of soil moisture measurements from eight locations across Oklahoma to calculate soil water deficits and determine the days on which dry conditions would be likely. Results of the study, which began as a student-led class research project, were published online Jan. 29 inAgronomy Journal. The researchers found that soil water deficits more successfully identified periods during which plants were likely to be water stressed than did traditional atmospheric measurements when used as proposed by previous research.

Soil water deficit is defined in the study as the difference between the capacity of the soil to hold water and the actual water content calculated from long-term soil moisture measurements. Researchers then compared that soil water deficit to a threshold at which plants would experience water stress and, therefore, drought conditions. The threshold was determined for each study site since available water, a factor used to calculate threshold, is affected by specific soil characteristics.

“The soil water contents differ across sites and depths depending on the sand, silt, and clay contents,” says Ochsner. “Readily available water is a site- and depth-specific parameter.”

Upon calculating soil water deficits and stress thresholds for the study sites, the research team compared their assessment of drought probability to assessments made using atmospheric data. They found that a previously developed method using atmospheric data often underestimated drought conditions, while soil water deficits measurements more accurately and consistently assessed drought probabilities. Therefore, the researchers suggest that soil water data be used whenever it is available to create a picture of the days on which drought conditions are likely.

If soil measurements are not available, however, the researchers recommend that the calculations used for atmospheric assessments be reconfigured to be more accurate. The authors made two such changes in their study. First, they decreased the threshold at which plants were deemed stressed, thus allowing a smaller deficit to be considered a drought condition. They also increased the number of days over which atmospheric deficits were summed. Those two changes provided estimates that better agreed with soil water deficit probabilities.

Further research is needed, says Ochsner, to optimize atmospheric calculations and provide accurate estimations for those without soil water data. “We are in a time of rapid increase in the availability of soil moisture data, but many users will still have to rely on the atmospheric water deficit method for locations where soil moisture data are insufficient.”

Regardless of the method used, Ochsner and his team hope that their research will help farmers better plan the cultivation of their crops and avoid costly losses to drought conditions.

Journal Reference:

Guilherme M. Torres, Romulo P. Lollato, Tyson E. Ochsner.Comparison of Drought Probability Assessments Based on Atmospheric Water Deficit and Soil Water Deficit.Agronomy Journal, 2013; DOI: 10.2134/agronj2012.0295

Make climate change a priority (Washington Post)

29/01/2013UncategorizedBanco Mundial, Cidadania, Clima, Economia, Enquadramento, Incerteza, Mediação tecnológica, Meteorologia, Mudanças climáticas, Opinião pública, Política, Políticas públicas, Previsãorenzotaddei

Graphic: A new report prepared for the World Bank finds that the planet is on a path to warming 4 degrees by the end of the century, with devastating consequences. Click on the infographic to go to the World Bank for more information.

By Jim Yong Kim, Published: January 24

Jim Yong Kim is president of the World Bank.

The weather in Washington has been like a roller coaster this January. Yes, there has been a deep freeze this week, but it was the sudden warmth earlier in the month that was truly alarming. Flocks of birds — robins, wrens, cardinals and even blue jays – swarmed bushes with berries, eating as much as they could. Runners and bikers wore shorts and T-shirts. People worked in their gardens as if it were spring.

The signs of global warming are becoming more obvious and more frequent. A glut of extreme weather conditions is appearing globally. And the average temperature in the United States last year was the highest ever recorded.

As economic leaders gathered in Davos this week for the World Economic Forum, much of the conversation was about finances. But climate change should also be at the top of our agendas, because global warming imperils all of the development gains we have made.If there is no action soon, the future will become bleak. The World Bank Groupreleased a reportin November that concluded that the world could warm by 7.2 degrees Fahrenheit (4 degrees Celsius) by the end of this century if concerted action is not taken now.

A world that warm means seas would rise 1.5 to 3 feet, putting at risk hundreds of millions of city dwellers globally. It would mean that storms once dubbed “once in a century” would become common, perhaps occurring every year. And it would mean that much of the United States, from Los Angeles to Kansas to the nation’s capital, would feel like an unbearable oven in the summer.

My wife and I have two sons, ages 12 and 3. When they grow old, this could be the world they inherit. That thought alone makes me want to be part of a global movement that acts now.

Even as global climate negotiations continue, there is a need for urgent action outside the conventions. People everywhere must focus on where we will get the most impact to reduce emissions and build resilience in cities, communities and countries.

Strong leadership must come from the six big economies that account for two-thirds of the energy sector’s global carbon dioxide emissions. President Obama’s reference in his inaugural address this week to addressing climate and energy could help reignite this critical conversation domestically and abroad.

The world’s top priority must be to get finance flowing and get prices right on all aspects of energy costs to support low-carbon growth. Achieving a predictable price on carbon that accurately reflects real environmental costs is key to delivering emission reductions at scale. Correct energy pricing can also provide incentives for investments in energy efficiency and cleaner energy technologies.

A second immediate step is to end harmful fuel subsidies globally, which could lead to a 5 percent fall in emissions by 2020. Countries spend more than $500 billion annually in fossil-fuel subsidies and an additional $500 billion in other subsidies, often related to agriculture and water, that are, ultimately, environmentally harmful. That trillion dollars could be put to better use for the jobs of the future, social safety nets or vaccines.

A third focus is on cities. The largest 100 cities that contribute 67 percent of energy-related emissions are both the center of innovation for green growth and the most vulnerable to climate change. We have seen great leadership, for example, in New York and Rio de Janeiro on low-carbon growth and tackling practices that fuel climate change.

At the World Bank Group, through the $7 billion-plus Climate Investment Funds, we are managing forests, spreading solar energy and promoting green expansion for cities, all with a goal of stopping global warming. We also are in the midst of a major reexamination of our own practices and policies.

Just as the Bretton Woods institutions were created to prevent a third world war, the world needs a bold global approach to help avoid the climate catastrophe it faces today. The World Bank Group is ready to work with others to meet this challenge. With every investment we make and every action we take, we should have in mind the threat of an even warmer world and the opportunity of inclusive green growth.

After the hottest year on record in the United States, a year in which Hurricane Sandycaused billions of dollars in damage, record droughts scorched farmland in the Midwest and our organization reported that the planet could become more than 7 degrees warmer, what are we waiting for? We need to get serious fast. The planet, our home, can’t wait.

Climate Change Beliefs of Independent Voters Shift With the Weather (Science Daily)

25/01/2013UncategorizedClima, Enquadramento, Incerteza, Meteorologia, Mudanças climáticas, Opinião pública, Política, Previsãorenzotaddei

Jan. 24, 2013 — There’s a well-known saying in New England that if you don’t like the weather here, wait a minute. When it comes to independent voters, those weather changes can just as quickly shift beliefs about climate change.

Predicted probability of “climate change is happening now, caused mainly by human activities” response as a function of temperature anomaly and political party. (Credit: Lawrence Hamilton and Mary Stampone/UNH)

New research from the University of New Hampshire finds that the climate change beliefs of independent voters are dramatically swayed by short-term weather conditions. The research was conducted by Lawrence Hamilton, professor of sociology and senior fellow at the Carsey Institute, and Mary Stampone, assistant professor of geography and the New Hampshire state climatologist.

“We find that over 10 surveys, Republicans and Democrats remain far apart and firm in their beliefs about climate change. Independents fall in between these extremes, but their beliefs appear weakly held — literally blowing in the wind. Interviewed on unseasonably warm days, independents tend to agree with the scientific consensus on human-caused climate change. On unseasonably cool days, they tend not to,” Hamilton and Stampone say.

Hamilton and Stampone used statewide data from about 5,000 random-sample telephone interviews conducted on 99 days over two and a half years (2010 to 2012) by the Granite State Poll. They combined the survey data with temperature and precipitation indicators derived from New Hampshire’s U.S. Historical Climatology Network (USHCN) station records. Survey respondents were asked whether they thought climate change is happening now, caused mainly by human activities. Alternatively, respondents could state that climate change is not happening, or that it is happening but mainly for natural reasons.

Unseasonably warm or cool temperatures on the interview day and previous day seemed to shift the odds of respondents believing that humans are changing the climate. However, when researchers broke these responses down by political affiliation (Democrat, Republican or independent), they found that temperature had a substantial effect on climate change views mainly among independent voters.

“Independent voters were less likely to believe that climate change was caused by humans on unseasonably cool days and more likely to believe that climate change was caused by humans on unseasonably warm days. The shift was dramatic. On the coolest days, belief in human-caused climate change dropped below 40 percent among independents. On the hottest days, it increased above 70 percent,” Hamilton says.

New Hampshire’s self-identified independents generally resemble their counterparts on a nationwide survey that asked the same questions, according to the researchers. Independents comprise 18 percent of the New Hampshire estimation sample, compared with 17 percent nationally. They are similar with respect to education, but slightly older, and more balanced with respect to gender.

In conducting their analysis, the researchers took into account other factors such as education, age, and sex. They also made adjustments for the seasons, and for random variation between surveys that might be caused by nontemperature events.

Journal Reference:

Lawrence C. Hamilton, Mary D. Stampone. Blowin’ in the wind: Short-term weather and belief in anthropogenic climate change. Weather, Climate, and Society, 2013; : 130123150419007 DOI: 10.1175/WCAS-D-12-00048.1

The Storm That Never Was: Why Meteorologists Are Often Wrong (Science Daily)

25/01/2013UncategorizedClima, Incerteza, Matemática, Mediação tecnológica, Meteorologia, Previsãorenzotaddei

Jan. 24, 2013 — Have you ever woken up to a sunny forecast only to get soaked on your way to the office? On days like that it’s easy to blame the weatherman.

BYU engineering professor Julie Crockett studies waves in the ocean and the atmosphere. (Credit: Image courtesy of Brigham Young University)

But BYU mechanical engineering professor Julie Crockett doesn’t get mad at meteorologists. She understands something that very few people know: it’s not the weatherman’s fault he’s wrong so often.

According to Crockett, forecasters make mistakes because the models they use for predicting weather can’t accurately track highly influential elements called internal waves.

Atmospheric internal waves are waves that propagate between layers of low-density and high-density air. Although hard to describe, almost everyone has seen or felt these waves. Cloud patterns made up of repeating lines are the result of internal waves, and airplane turbulence happens when internal waves run into each other and break.

“Internal waves are difficult to capture and quantify as they propagate, deposit energy and move energy around,” Crockett said. “When forecasters don’t account for them on a small scale, then the large scale picture becomes a little bit off, and sometimes being just a bit off is enough to be completely wrong about the weather.”

One such example may have happened in 2011, when Utah meteorologists predicted an enormous winter storm prior to Thanksgiving. Schools across the state cancelled classes and sent people home early to avoid the storm. Though it’s impossible to say for sure, internal waves may have been driving stronger circulations, breaking up the storm and causing it to never materialize.

“When internal waves deposit their energy it can force the wind faster or slow the wind down such that it can enhance large scale weather patterns or extreme kinds of events,” Crockett said. “We are trying to get a better feel for where that wave energy is going.”

Internal waves also exist in oceans between layers of low-density and high-density water. These waves, often visible from space, affect the general circulation of the ocean and phenomena like the Gulf Stream and Jet Stream.

Both oceanic and atmospheric internal waves carry a significant amount of energy that can alter climates.

Crockett’s latest wave research, which appears in a recent issue of the International Journal of Geophysics, details how the relationship between large-scale and small-scale internal waves influences the altitude where wave energy is ultimately deposited.

To track wave energy, Crockett and her students generate waves in a tank in her lab and study every aspect of their behavior. She and her colleagues are trying to pinpoint exactly how climate changes affect waves and how those waves then affect weather.

Based on this, Crockett can then develop a better linear wave model with both 3D and 2D modeling that will allow forecasters to improve their weather forecasting.

“Understanding how waves move energy around is very important to large scale climate events,” Crockett said. “Our research is very important to this problem, but it hasn’t solved it completely.”

Journal Reference:

B. Casaday, J. Crockett. Investigation of High-Frequency Internal Wave Interactions with an Enveloped Inertia Wave. International Journal of Geophysics, 2012; 2012: 1 DOI: 10.1155/2012/863792

Global Warming Has Increased Monthly Heat Records Worldwide by a Factor of Five, Study Finds (Science Daily)

23/01/2013UncategorizedClima, Incerteza, Meteorologia, Mudanças climáticas, Previsãorenzotaddei

Jan. 14, 2013 — Monthly temperature extremes have become much more frequent, as measurements from around the world indicate. On average, there are now five times as many record-breaking hot months worldwide than could be expected without long-term global warming, shows a study now published in Climatic Change. In parts of Europe, Africa and southern Asia the number of monthly records has increased even by a factor of ten. 80 percent of observed monthly records would not have occurred without human influence on climate, concludes the authors-team of the Potsdam Institute for Climate Impact Research (PIK) and the Complutense University of Madrid.

Record-breaking hot months have become much more frequent. (Credit: PIK)

“The last decade brought unprecedented heat waves; for instance in the US in 2012, in Russia in 2010, in Australia in 2009, and in Europe in 2003,” lead-author Dim Coumou says. “Heat extremes are causing many deaths, major forest fires, and harvest losses — societies and ecosystems are not adapted to ever new record-breaking temperatures.” The new study relies on 131 years of monthly temperature data for more than 12,000 grid points around the world, provided by NASA. Comprehensive analysis reveals the increase in records.

The researchers developed a robust statistical model that explains the surge in the number of records to be a consequence of the long-term global warming trend. That surge has been particularly steep over the last 40 years, due to a steep global-warming trend over this period. Superimposed on this long-term rise, the data show the effect of natural variability, with especially high numbers of heat records during years with El Niño events. This natural variability, however, does not explain the overall development of record events, found the researchers.

Natural variability does not explain the overall development of record events

If global warming continues, the study projects that the number of new monthly records will be 12 times as high in 30 years as it would be without climate change. “Now this doesn’t mean there will be 12 times more hot summers in Europe than today — it actually is worse,” Coumou points out. For the new records set in the 2040s will not just be hot by today’s standards. “To count as new records, they actually have to beat heat records set in the 2020s and 2030s, which will already be hotter than anything we have experienced to date,” explains Coumou. “And this is just the global average — in some continental regions, the increase in new records will be even greater.”

“Statistics alone cannot tell us what the cause of any single heat wave is, but they show a large and systematic increase in the number of heat records due to global warming,” says Stefan Rahmstorf, a co-author of the study and co-chair of PIK’s research domain Earth System Analysis. “Today, this increase is already so large that by far most monthly heat records are due to climate change. The science is clear that only a small fraction would have occurred naturally.”

Journal Reference:

Dim Coumou, Alexander Robinson, Stefan Rahmstorf.Global increase in record-breaking monthly-mean temperatures. Climatic Change, 2013; DOI:10.1007/s10584-012-0668-1

Severe Climate Jeopardizing Amazon Forest, Study Finds (Science Daily)

23/01/2013UncategorizedAmazônia, Clima, Meteorologia, Mudanças climáticas, Previsão, Secarenzotaddei

Jan. 18, 2013 — An area of the Amazon rainforest twice the size of California continues to suffer from the effects of a megadrought that began in 2005, finds a new NASA-led study. These results, together with observed recurrences of droughts every few years and associated damage to the forests in southern and western Amazonia in the past decade, suggest these rainforests may be showing the first signs of potential large-scale degradation due to climate change.

At left, the extent of the 2005 megadrought in the western Amazon rainforests during the summer months of June, July and August as measured by NASA satellites. The most impacted areas are shown in shades of red and yellow. The circled area in the right panel shows the extent of the forests that experienced slow recovery from the 2005 drought, with areas in red and yellow shades experiencing the slowest recovery. (Credit: NASA/JPL-Caltech/GSFC)

An international research team led by Sassan Saatchi of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., analyzed more than a decade of satellite microwave radar data collected between 2000 and 2009 over Amazonia. The observations included measurements of rainfall from NASA’s Tropical Rainfall Measuring Mission and measurements of the moisture content and structure of the forest canopy (top layer) from the Seawinds scatterometer on NASA’s QuikScat spacecraft.

The scientists found that during the summer of 2005, more than 270,000 square miles (700,000 square kilometers, or 70 million hectares) of pristine, old-growth forest in southwestern Amazonia experienced an extensive, severe drought. This megadrought caused widespread changes to the forest canopy that were detectable by satellite. The changes suggest dieback of branches and tree falls, especially among the older, larger, more vulnerable canopy trees that blanket the forest.

While rainfall levels gradually recovered in subsequent years, the damage to the forest canopy persisted all the way to the next major drought, which began in 2010. About half the forest affected by the 2005 drought — an area the size of California — did not recover by the time QuikScat stopped gathering global data in November 2009 and before the start of a more extensive drought in 2010.

“The biggest surprise for us was that the effects appeared to persist for years after the 2005 drought,” said study co-author Yadvinder Malhi of the University of Oxford, United Kingdom. “We had expected the forest canopy to bounce back after a year with a new flush of leaf growth, but the damage appeared to persist right up to the subsequent drought in 2010.”

Recent Amazonian droughts have drawn attention to the vulnerability of tropical forests to climate change. Satellite and ground data have shown an increase in wildfires during drought years and tree die-offs following severe droughts. Until now, there had been no satellite-based assessment of the multi-year impacts of these droughts across all of Amazonia. Large-scale droughts can lead to sustained releases of carbon dioxide from decaying wood, affecting ecosystems and Earth’s carbon cycle.

The researchers attribute the 2005 Amazonian drought to the long-term warming of tropical Atlantic sea surface temperatures. “In effect, the same climate phenomenon that helped form hurricanes Katrina and Rita along U.S. southern coasts in 2005 also likely caused the severe drought in southwest Amazonia,” Saatchi said. “An extreme climate event caused the drought, which subsequently damaged the Amazonian trees.”

Saatchi said such megadroughts can have long-lasting effects on rainforest ecosystems. “Our results suggest that if droughts continue at five- to 10-year intervals or increase in frequency due to climate change, large areas of the Amazon forest are likely to be exposed to persistent effects of droughts and corresponding slow forest recovery,” he said. “This may alter the structure and function of Amazonian rainforest ecosystems.”

The team found that the area affected by the 2005 drought was much larger than scientists had previously predicted. About 30 percent (656,370 square miles, or 1.7 million square kilometers) of the Amazon basin’s total current forest area was affected, with more than five percent of the forest experiencing severe drought conditions. The 2010 drought affected nearly half of the entire Amazon forest, with nearly a fifth of it experiencing severe drought. More than 231,660 square miles (600,000 square kilometers) of the area affected by the 2005 drought were also affected by the 2010 drought. This “double whammy” by successive droughts suggests a potentially long-lasting and widespread effect on forests in southern and western Amazonia.

The drought rate in Amazonia during the past decade is unprecedented over the past century. In addition to the two major droughts in 2005 and 2010, the area has experienced several localized mini-droughts in recent years. Observations from ground stations show that rainfall over the southern Amazon rainforest declined by almost 3.2 percent per year in the period from 1970 to 1998. Climate analyses for the period from 1995 to 2005 show a steady decline in water availability for plants in the region. Together, these data suggest a decade of moderate water stress led up to the 2005 drought, helping trigger the large-scale forest damage seen following the 2005 drought.

Saatchi said the new study sheds new light on a major controversy that existed about how the Amazon forest responded following the 2005 megadrought. Previous studies using conventional optical satellite data produced contradictory results, likely due to the difficulty of correcting the optical data for interference by clouds and other atmospheric conditions.

In contrast, QuikScat’s scatterometer radar was able to see through the clouds and penetrate into the top few meters of vegetation, providing daily measurements of the forest canopy structure and estimates of how much water the forest contains. Areas of drought-damaged forest produced a lower radar signal than the signals collected over healthy forest areas, indicating either that the forest canopy is drier or it is less “rough” due to damage to or the death of canopy trees.

Results of the study were published recently in the Proceedings of the National Academy of Sciences. Other participating institutions included UCLA; University of Oxford, United Kingdom; University of Exeter, Devon, United Kingdom; National Institute for Space Research, Sao Jose dos Campos, Sao Paulo, Brazil; Boston University, Mass.; and NASA’s Ames Research Center, Moffett Field, Calif.

For more on NASA’s scatterometry missions, visit:http://winds.jpl.nasa.gov/index.cfm . You can follow JPL News on Facebook at: http://www.facebook.com/nasajpl and on Twitter at: http://www.twitter.com/nasajpl . The California Institute of Technology in Pasadena manages JPL for NASA.

New Insights On Drought Predictions in East Africa (Science Daily)

23/01/2013UncategorizedClima, Incerteza, Meteorologia, Mudanças climáticas, Políticas públicas, Previsão, Secarenzotaddei

Jan. 18, 2013 — With more than 40 million people living under exceptional drought conditions in East Africa, the ability to make accurate predictions of drought has never been more important. In the aftermath of widespread famine and a humanitarian crisis caused by the 2010-2011 drought in the Horn of Africa — possibly the worst drought in 60 years — researchers are striving to determine whether drying trends will continue.

Climate model simulations analyzed as part of the study revealed that the relationship between sea surface temperatures and atmospheric convection in the Indian Ocean changes rainfall in East Africa. Specifically, wet conditions in coastal East Africa are associated with cool sea surface temperatures in the eastern Indian Ocean and warm sea surface temperatures in the western Indian Ocean, which cause ascending atmospheric circulation over East Africa and enhanced rainfall. The opposite situation—cold sea surface temperatures in the western Indian Ocean and warmer in the East—causes drought. Such variations in sea-surface temperatures likely caused the historical fluctuations in rainfall seen in the paleorecord. (Credit: Courtesy Jessica Tierney, et al, 2013)

While it is clear that El Niño can affect precipitation in this region of East Africa, very little is known about the drivers of long-term shifts in rainfall. However, new research described in the journal Nature helps explain the mechanisms at work behind historical patterns of aridity in Eastern Africa over many decades, and the findings may help improve future predictions of drought and food security in the region.

“The problem is, instrumental records of temperature and rainfall, especially in East Africa, don’t go far enough in time to study climate variability over decades or more, since they are generally limited to the 20th century,” explains first author Jessica Tierney, a geologist at the Woods Hole Oceanographic Institution (WHOI). Tierney and her colleagues at WHOI and the Lamont-Doherty Earth Observatory of Columbia University used what is known as the paleoclimate record, which provides information on climate in the geologic past, to study East African climate change over a span of 700 years.

The paleoclimate record in East Africa consists of indicators of moisture balance — including pollen, water isotopes, charcoal, and evidence for run-off events — measured in lake sediment cores. Tierney and her colleagues synthesized these data, revealing a clear pattern wherein the easternmost sector of East Africa was relatively dry in medieval times (from 1300 to 1400 a.d.), wet during the “Little Ice Age” from approximately 1600 to 1800 a.d., and then drier again toward the present time.

Climate model simulations analyzed as part of the study revealed that the relationship between sea surface temperatures and atmospheric convection in the Indian Ocean changes rainfall in East Africa. Specifically, wet conditions in coastal East Africa are associated with cool sea surface temperatures in the eastern Indian Ocean and warm sea surface temperatures in the western Indian Ocean, which cause ascending atmospheric circulation over East Africa and enhanced rainfall. The opposite situation — cold sea surface temperatures in the western Indian Ocean and warmer in the East — causes drought. Such variations in sea-surface temperatures likely caused the historical fluctuations in rainfall seen in the paleorecord.

The central role of the Indian Ocean in long-term climate change in the region was a surprise. “While the Indian Ocean has long been thought of as a ‘little brother’ to the Pacific, it is clear that it is in charge when it comes to these decades-long changes in precipitation in East Africa,” says Tierney.

Many questions remain, though. “We still don’t understand exactly what causes the changes in sea surface temperatures in the Indian Ocean and the relationship between those changes and global changes in climate, like the cooling that occurred during the Little Ice Age or the global warming that is occurring now,” says Tierney. “We’ll need to do some more experiments with climate models to understand that better.”

In the past decade, the easternmost region of Africa has gotten drier, yet general circulation climate models predict that the region will become wetter in response to global warming. “Given the geopolitical significance of the region, it is very important to understand whether drying trends will continue, in which case the models will need to be revised, or if the models will eventually prove correct in their projections of increased precipitation in East Africa,” says co-author Jason Smerdon, of the Lamont-Doherty Earth Observatory.

While it’s currently unclear which theory is correct, the discovery of the importance of the Indian Ocean may help solve the mystery. “In terms of forecasting long-term patterns in drought and food security, we would recommend that researchers make use of patterns of sea surface temperature changes in the Indian Ocean rather than just looking at the shorter term El Niño events or the Pacific Ocean,” says Tierney.

In addition, Tierney and her colleagues lack paleoclimate data from the region that is most directly affected by the Indian Ocean — the Horn of Africa. The paleoclimate data featured in this study are limited to more equatorial and interior regions of East Africa. With support from National Science Foundation, Tierney and her colleagues are now developing a new record of both aridity and sea surface temperatures from the Gulf of Aden, at a site close to the Horn.

“This will give us the best picture of what’s happened to climate in the Horn, and in fact, it will be the first record of paleoclimate in the Horn that covers the last few millennia in detail. We’re working on those analyses now and should have results in the next year or so,” says Tierney.

This research was based on work supported by the National Science Foundation and the National Oceanic and Atmospheric Administration (NOAA).

Journal Reference:

Jessica E. Tierney, Jason E. Smerdon, Kevin J. Anchukaitis, Richard Seager. Multidecadal variability in East African hydroclimate controlled by the Indian Ocean. Nature, 2013; 493 (7432): 389 DOI:10.1038/nature11785

Cacique Cobra Coral rompe parceria com a prefeitura (O Globo)

22/01/2013UncategorizedDesastre, discurso ambiental, Enquadramento, Fundação Cacique Cobra Coral, Incerteza, Meteorologia, Mudanças climáticas, Opinião pública, Política, Previsão, Sensacionalismo, Visualidaderenzotaddei

Governo teria deixado de entregar, nos prazos previstos, relatórios com um balanço dos investimentos em prevenção realizados ano passado na cidade

O GLOBO

Publicado:14/01/13 – 0h08

RIO — Em pleno verão carioca, o sistema de alerta e prevenção a enchentes do Rio perdeu um colaborador incomum. O porta-voz da Fundação Cacique Cobra Coral, Osmar Santos, anunciou no domingo que rompeu o convênio técnico-científico que mantinha com a prefeitura do Rio. O motivo é que a prefeitura deixou de entregar, nos prazos previstos, relatórios com um balanço dos investimentos em prevenção realizados ano passado na cidade. A ONG é comandada pela médium Adelaide Scritori, que afirma ter o poder de controlar o tempo. Desde a administração do ex-prefeito Cesar Maia, Adelaide esteve à disposição para prestar assistência espiritual a fim de tentar reduzir os estragos causados por temporais. Em janeiro de 2009, a prefeitura chegou a anunciar o fim da parceria, mas voltou atrás após uma forte chuva.

— Alguém da burocracia muito atarefado esqueceu da gente. Mas, caso a prefeitura queira continuar a receber nossa consultoria, que é gratuita, estamos à disposição — disse Osmar Santos.

Leia mais sobre esse assunto em http://oglobo.globo.com/rio/cacique-cobra-coral-rompe-parceria-com-prefeitura-7285402#ixzz2Il9blV38 © 1996 – 2013. Todos direitos reservados a Infoglobo Comunicação e Participações S.A. Este material não pode ser publicado, transmitido por broadcast, reescrito ou redistribuído sem autorização.

Heat, Flood or Icy Cold, Extreme Weather Rages Worldwide (N.Y.Times)

11/01/2013UncategorizedClima, Desastre, Incerteza, jornalismo, Meteorologia, Mudanças climáticas, Opinião pública, Previsãorenzotaddei

NY Times

January 10, 2013

By SARAH LYALL

WORCESTER, England — Britons may remember 2012 as the year the weather spun off its rails in a chaotic concoction of drought, deluge and flooding, but the unpredictability of it all turns out to have been all too predictable: Around the world, extreme has become the new commonplace.

Especially lately. China is enduring its coldest winter in nearly 30 years. Brazil is in the grip of a dreadful heat spell. Eastern Russia is so freezing — minus 50 degrees Fahrenheit, and counting — that the traffic lights recently stopped working in the city of Yakutsk.

Bush fires are raging across Australia, fueled by a record-shattering heat wave. Pakistan was inundated by unexpected flooding in September. A vicious storm bringing rain, snow and floods just struck the Middle East. And in the United States, scientists confirmed this week what people could have figured out simply by going outside: last year was the hottest since records began.

“Each year we have extreme weather, but it’s unusual to have so many extreme events around the world at once,” said Omar Baddour, chief of the data management applications division at the World Meteorological Organization, in Geneva. “The heat wave in Australia; the flooding in the U.K., and most recently the flooding and extensive snowstorm in the Middle East — it’s already a big year in terms of extreme weather calamity.”

Such events are increasing in intensity as well as frequency, Mr. Baddour said, a sign that climate change is not just about rising temperatures, but also about intense, unpleasant, anomalous weather of all kinds.

Here in Britain, people are used to thinking of rain as the wallpaper on life’s computer screen — an omnipresent, almost comforting background presence. But even the hardiest citizen was rattled by the near-biblical fierceness of the rains that bucketed down, and the floods that followed, three different times in 2012.

Rescuers plucked people by boat from their swamped homes in St. Asaph, North Wales. Whole areas of the country were cut off when roads and train tracks were inundated at Christmas. In Megavissey, Cornwall, a pub owner closed his business for good after it flooded 11 times in two months.

It was no anomaly: the floods of 2012 followed the floods of 2007 and also the floods of 2009, which all told have resulted in nearly $6.5 billion in insurance payouts. The Met Office, Britain’s weather service, declared 2012 the wettest year in England, and the second-wettest in Britain as a whole, since records began more than 100 years ago. Four of the five wettest years in the last century have come in the past decade (the fifth was in 1954).

The biggest change, said Charles Powell, a spokesman for the Met Office, is the frequency in Britain of “extreme weather events” — defined as rainfall reaching the top 1 percent of the average amount for that time of year. Fifty years ago, such episodes used to happen every 100 days; now they happen every 70 days, he said.

The same thing is true in Australia, where bush fires are raging across Tasmania and the current heat wave has come after two of the country’s wettest years ever. On Tuesday, Sydney experienced its fifth-hottest day since records began in 1910, with the temperature climbing to 108.1 degrees. The first eight days of 2013 were among the 20 hottest on record.

Every decade since the 1950s has been hotter in Australia than the one before, said Mark Stafford Smith, science director of the Climate Adaptation Flagship at the Commonwealth Scientific and Industrial Research Organization.

To the north, the extremes have swung the other way, with a band of cold settling across Russia and Northern Europe, bringing thick snow and howling winds to Stockholm, Helsinki and Moscow. (Incongruously, there were also severe snowstorms in Sicily and southern Italy for the first time since World War II; in December, tornadoes and waterspouts struck the Italian coast.)

In Siberia, thousands of people were left without heat when natural gas liquefied in its pipes and water mains burst. Officials canceled bus transportation between cities for fear that roadside breakdowns could lead to deaths from exposure, and motorists were advised not to venture far afield except in columns of two or three cars. In Altai, to the east, traffic officials warned drivers not to use poor-quality diesel, saying that it could become viscous in the cold and clog fuel lines.

Meanwhile, China is enduring its worst winter in recent memory, with frigid temperatures recorded in Harbin, in the northeast. In the western region of Xinjiang, more than 1,000 houses collapsed under a relentless onslaught of snow, while in Inner Mongolia, 180,000 livestock froze to death. The cold has wreaked havoc with crops, sending the price of vegetables soaring.

Way down in South America, energy analysts say that Brazil may face electricity rationing for the first time since 2002, as a heat wave and a lack of rain deplete the reservoirs for hydroelectric plants. The summer has been punishingly hot. The temperature in Rio de Janeiro climbed to 109.8 degrees on Dec. 26, the city’s highest temperature since official records began in 1915.

At the same time, in the Middle East, Jordan is battling a storm packing torrential rain, snow, hail and floods that are cascading through tunnels, sweeping away cars and spreading misery in Syrian refugee camps. Amman has been virtually paralyzed, with cars abandoned, roads impassable and government offices closed.

Israel and the Palestinian territories are grappling with similar conditions, after a week of intense rain and cold winds ushered in a snowstorm that dumped eight inches in Jerusalem alone.

Amir Givati, head of the surface water department at the Israel Hydrological Service, said the storm was truly unusual because of its duration, its intensity and its breadth. Snow and hail fell not just in the north, but as far south as the desert city of Dimona, best known for its nuclear reactor.

In Beirut on Wednesday night, towering waves crashed against the Corniche, the seaside promenade downtown, flinging water and foam dozens of feet in the air as lightning flickered across the dark sea at multiple points along the horizon. Many roads were flooded as hail pounded the city.

Several people died, including a baby boy in a family of shepherds who was swept out of his mother’s arms by floodwaters. The greatest concern was for the 160,000 Syrian refugees who have fled to Lebanon, taking shelter in schools, sheds and, where possible, with local families. Some refugees are living in farm outbuildings, which are particularly vulnerable to cold and rain.

Barry Lynn, who runs a forecasting business and is a lecturer at the Hebrew University’s department of earth science, said a striking aspect of the whole thing was the severe and prolonged cold in the upper atmosphere, a big-picture shift that indicated the Atlantic Ocean was no longer having the moderating effect on weather in the Middle East and Europe that it has historically.

“The intensity of the cold is unusual,” Mr. Lynn said. “It seems the weather is going to become more intense; there’s going to be more extremes.”

In Britain, where changes to the positioning of the jet stream — a ribbon of air high up in the atmosphere that helps steer weather systems — may be contributing to the topsy-turvy weather, people are still recovering from the December floods. In Worcester last week, the river Severn remained flooded after three weeks, with playing fields buried under water.

In the shop at the Worcester Cathedral, Julie Smith, 54, was struggling, she said, to adjust to the new uncertainty.

“For the past seven or eight years, there’s been a serious incident in a different part of the country,” Mrs. Smith said. “We don’t expect extremes. We don’t expect it to be like this.”

Reporting was contributed by Jodi Rudoren from Jerusalem; Irit Pazner Garshowitz from Tzur Hadassah, Israel; Fares Akram from Gaza City, Gaza; Ellen Barry and Andrew Roth from Moscow; Ranya Kadri from Amman, Jordan; Dan Levin from Harbin, China; Jim Yardley from New Delhi; Anne Barnard from Beirut, Lebanon; Matt Siegel from Sydney, Australia; Scott Sayare from Paris; and Simon Romero from Rio de Janeiro.

* * *

It’s Official: 2012 Was Hottest Year Ever in U.S.

By JUSTIN GILLIS

NY Times, January 8, 2012

http://www.nytimes.com/2013/01/09/science/earth/2012-was-hottest-year-ever-in-us.html?hp&_r=0

The numbers are in: 2012, the year of a surreal March heat wave, a severe drought in the corn belt and a massive storm that caused broad devastation in the mid-Atlantic states, turns out to have been the hottest year ever recorded in the contiguous United States.

How hot was it? The temperature differences between years are usually measured in fractions of a degree, but last year blew away the previous record, set in 1998, by a full degree Fahrenheit.

If that does not sound sufficiently impressive, consider that 34,008 new daily high records were set at weather stations across the country, compared with only 6,664 new record lows, according to a count maintained by the Weather Channel meteorologist Guy Walton, using federal temperature records.

That ratio, which was roughly in balance as recently as the 1970s, has been out of whack for decades as the country has warmed, but never by as much as it was last year.

“The heat was remarkable,” said Jake Crouch, a scientist with the National Climatic Data Center in Asheville, N.C., which released the official climate compilation on Tuesday. “It was prolonged. That we beat the record by one degree is quite a big deal.”

Scientists said that natural variability almost certainly played a role in last year’s extreme heat and drought. But many of them expressed doubt that such a striking new record would have been set without the backdrop of global warming caused by the human release of greenhouse gases. And they warned that 2012 was likely a foretaste of things to come, as continuing warming makes heat extremes more likely.

Even so, the last year’s record for the United States is not expected to translate into a global temperature record when figures are released in coming weeks. The year featured a La Niña weather pattern, which tends to cool the global climate over all, and scientists expect it to be the world’s eighth or ninth warmest year on record.

Assuming that prediction holds up, it will mean that the 10 warmest years on record all fell within the past 15 years, a measure of how much the planet has warmed. Nobody who is under 28 has lived through a month of global temperatures that fell below the 20th-century average, because the last such month was February 1985.

Last year’s weather in the United States began with an unusually warm winter, with relatively little snow across much of the country, followed by a March that was so hot that trees burst into bloom and swimming pools opened early. The soil dried out in the March heat, helping to set the stage for a drought that peaked during the warmest July on record.

The drought engulfed 61 percent of the nation, killed corn and soybean crops and sent prices spiraling. It was comparable to a severe drought in the 1950s, Mr. Crouch said, but not quite as severe as the legendary Dust Bowl drought of the 1930s, which was exacerbated by poor farming practices that allowed topsoil to blow away.

Extensive records covering the lower 48 states go back to 1895; Alaska and Hawaii have shorter records and are generally not included in long-term climate comparisons for that reason.

Mr. Crouch pointed out that until last year, the coldest year in the historical record for the lower 48 states, 1917, was separated from the warmest year, 1998, by only 4.2 degrees Fahrenheit. That is why the 2012 record, and its one degree increase over 1998, strikes climatologists as so unusual.

“We’re taking quite a large step above what the period of record has shown for the contiguous United States,” he said.

In addition to being the nation’s warmest year, 2012 turned out to be the second-worst on a measure called the Climate Extremes Index, surpassed only by 1998.

Experts are still counting, but so far 11 disasters in 2012 have exceeded a threshold of $1 billion in damages, including several tornado outbreaks; Hurricane Isaac, which hit the Gulf Coast in August; and, late in the year, Hurricane Sandy, which caused damage likely to exceed $60 billion in nearly half the states, primarily in the mid-Atlantic region.

Among those big disasters was one bearing a label many people had never heard before: the derecho, a line of severe, fast-moving thunderstorms that struck central and eastern parts of the country starting on June 29, killing more than 20 people, toppling trees and knocking out power for millions of households.

For people who escaped both the derecho and Hurricane Sandy relatively unscathed, the year may be remembered most for the sheer breadth and oppressiveness of the summer heat wave. By the calculations of the climatic data center, a third of the nation’s population experienced 10 or more days of summer temperatures exceeding 100 degrees Fahrenheit.

Among the cities that set temperature records in 2012 were Nashville; Athens, Ga.; and Cairo, Ill., all of which hit 109 degrees on June 29; Greenville, S.C., which hit 107 degrees on July 1; and Lamar, Colo., which hit 112 degrees on June 27.

With the end of the growing season, coverage of the drought has waned, but the drought itself has not. Mr. Crouch pointed out that at the beginning of January, 61 percent of the country was still in moderate to severe drought conditions. “I foresee that it’s going to be a big story moving forward in 2013,” he said.

Your weatherman probably denies global warming (Salon)

11/01/2013UncategorizedClima, Enquadramento, Incerteza, jornalismo, Mídia, Meteorologia, Mudanças climáticas, Opinião pública, Previsãorenzotaddei

FRIDAY, JAN 11, 2013 08:00 AM -0200

The good news: People can be persuaded climate change is real. The bad news: TV experts can’t

BY DAVID SIROTA

Your weatherman probably denies global warming

There’s a big reason climate change differs from so many public policy challenges: unlike other crises, addressing the planet’s major environmental crisis truly requires mass consensus. Indeed, because fixing the problem involves so many different societal changes — reducing carbon emissions, conserving energy, retrofitting infrastructure, altering a meat-centric diet, to name a few — we all need to at least agree on the basic fact that we are facing an emergency. This is especially the case in a nation where, thanks to the U.S. Senate filibuster, lawmakers representing just 11 percent of the population can kill almost any national legislation.

That’s why, as encouraging as it is to see a new Associated Press-GfK poll showing that 4 in 5 Americans now see climate change as a serious problem, it is also not so encouraging to see that after the hottest year on record, 1 in 5 still somehow do not acknowledge the crisis. Unfortunately, that 1 in 5 may be enough to prevent us from forging the all-hands-on-deck attitude necessary to halt a planetary disaster.

What, if anything, can be done? Short of eliminating the filibuster so that lawmakers representing this 20 percent don’t retain veto power over climate change legislation, America desperately needs a serious public education campaign.

The good news is that with such education, many of those who don’t yet believe climate change is a serious problem can, in fact, be reached — and convinced to accept obvious reality.

This is the conclusion of a new study by researchers at George Mason University and Yale University. It found that those with a “low engagement on the issue of global warming … are more likely to be influenced by their perceived personal experience of global warming than by their prior beliefs.” Summarizing the findings, Grist.org reporter David Roberts writes that “people who have made up their mind have made up their mind,” but for those in the “mushy middle,” personally facing severe weather — and being exposed to facts about what that weather really represents — “can make a real difference.”

The bad news is that this “mushy” group probably cannot be reached by the real experts, as 1 in 3 of those surveyed in the AP poll say they simply do not trust scientists. That leaves local television weather forecasters (many of whom are not actual scientists), national news outlets and Washington political leaders to the task — and up to this point, many of them have played the opposite of a constructive role in climate education.

For instance, when it comes to weather forecasters, a recent Rolling Stone magazine assessment of the local news scene found that “there’s a shockingly high chance that your friendly TV weatherman is a full-blown climate denier.” The report cited a 2010 survey finding that in the vast wasteland of Ron Burgundys, only half of all local weather forecasters believe climate change is even happening, and fewer than a third acknowledge the scientific evidence proving that it is “caused mostly by human activities.” Not surprisingly, their forecasts often omit any discussion of climate change’s effect on the weather systems, thus forfeiting a chance to properly contextualize severe weather events.

Similarly, an analysis in 2012 from the watchdog group Media Matters found that “the amount of climate coverage on both the Sunday shows and the nightly news has declined tremendously.” Meanwhile, the Columbia Journalism Review points out that the “presidential campaign was silent on the issue.”

In a nation that comprises just 5 percent of the world’s population but a whopping 18 percent of its carbon emissions, this situation is unacceptable.

If the first step toward solving a problem is getting past the denial stage, then it is long past time for news organizations and political leaders to end their climate denialism. Only then can we hope to reach the consensus on which our survival depends.

David Sirota is a nationally syndicated newspaper columnist, magazine journalist and the best-selling author of the books “Hostile Takeover,” “The Uprising” and “Back to Our Future.” E-mail him at ds@davidsirota.com, follow him on Twitter @davidsirota or visit his website at www.davidsirota.com.

Renee Lertzman: the difficulty of knowledge

18/12/2012UncategorizedClima, Cognição, Culpa, Enquadramento, Incerteza, Mídia, Meteorologia, Mudanças climáticas, Opinião pública, Previsão, Psicologia, Sensacionalismo, Visualidaderenzotaddei

By Renee Lertzman / December 16, 2012

The notion that one can feel deeply, passionately about a particular issue – and not do anything in practically about it – seems to have flummoxed the broader environmental community.

Why else would we continue to design surveys and polls gauging public opinions about climate change (or other serious ecological threats)? Such surveys – even high profile, well funded mass surveys – continue to reproduce pernicious myths regarding both human subjectivity and the so-called gaps between values and actions.

It is no surprise that data surfacing in a survey or poll will stand in stark contrast to the ‘down and dirty’ world of actions. We all know that surveys invoke all sorts of complicated things like wanting to sound smart/good/moral, one’s own self-concept vs. actual feelings or thoughts, and being corralled into highly simplistic renderings of what are hugely complex topics or issues (“do you worry about climate change/support carbon tax/drive to work each day etc?”). So there is the obvious limitation right now. However, more important is this idea that the thoughts or ideas people hold will translate into their daily life. Reflect for a moment on an issue you care very deeply about. Now consider how much in alignment your practices are, in relation with this issue. It takes seconds to see that in fact, we can have multiple and competing desires and commitments, quite easily.

So why is it so hard for us to carry this over into how we research environmental values, perceptions or beliefs?

If we accept from the get-go that we are complicated beings living in hugely complicated contexts, woven into networks extending far beyond our immediate grasp, it makes a lot of sense that I can care deeply for my children’s future quality of life (and climatic conditions), and still carry on business as usual. I may experience deep conflict, guilt, shame and pain, which I can shove to the edges of consciousness. I may manage to not even think about these issues, or create nifty rationalizations for my consumptive behaviors.

However, this does not mean I don’t care, have deep concern, and even profound anxieties.

Until we realize this basic fact – that we are multiple selves in social contexts, and dynamic and fluid – our communications work will be limited. Why? Because we continue to speak with audiences, design messaging, and carry out research with the mythical unitary self in mind. We try to trick, cajole, seduce people into caring about our ecological treasures. This is simply the wrong track. Rather than trick, why not invite? Rather than overcome ‘barriers,’ why not presume dilemmas, and set out to understand them?

There is also the fact that some knowledge is just too difficult to bear.

The concept of “difficult knowledge” relates to the fact that when we learn, we also let go of cherished beliefs or concepts, and this can be often quite painful. How we handle knowledge, in other words, can and should be done with this recognition. How can we best support one another to bear difficult knowledge?

One of the tricks of the trade for gifted psychotherapists is the ability to listen and converse. The therapist listens; not only for the meaning, but where there may be resistance. The places that make us squirm or laugh nervously or change the topic. This is regarded as where the riches lie – where we may find ourselves stuck despite our best intentions. If we were to practice a bit of this in our own work in environmental communications, my guess is we’d see less rah-rah cheerleading engagement styles, and more ‘let’s be real and get down to business’ sort of work.

And this is what we need, desperately.

Eight examples of where the IPCC has missed the mark on its predictions and projections (The Daily Climate)

17/12/2012UncategorizedClima, Desastre, Incerteza, IPCC, Meteorologia, Mudanças climáticas, Previsãorenzotaddei

flooded-768

A “king tide” leaves parts of Sausalito, Calif., flooded in 2010. Disagreement over the impact of ice-sheet melting on sea-level rise has led the Intergovernmental Panel on Climate Change to omit their influence – and thus underestimate sea-level rise – in recent reports, a pattern the panel repeats with other key findings. Photo by Yanna B./flickr.

Dec. 6, 2012

Correction appended

By Glenn Scherer
The Daily Climate

Scientists will tell you: There are no perfect computer models. All are incomplete representations of nature, with uncertainty built into them. But one thing is certain: Several fundamental projections found in Intergovernmental Panel on Climate Change reports have consistently underestimated real-world observations, potentially leaving world governments at doubt as to how to guide climate policy.

Emissions

At the heart of all IPCC projections are “emission scenarios:” low-, mid-, and high-range estimates for future carbon emissions. From these “what if” estimates flow projections for temperature, sea-rise, and more.

Projection: In 2001, the IPCC offered a range of fossil fuel and industrial emissions trends, from a best-case scenario of 7.7 billion tons of carbon released each year by 2010 to a worst-case scenario of 9.7 billion tons.

Reality: In 2010, global emissions from fossil fuels alone totaled 9.1 billion tons of carbon, according to federal government’s Earth Systems Research Laboratory.

Why the miss? While technically within the range, scientists never expected emissions to rise so high so quickly, said IPCC scientist Christopher Fields. The IPCC, for instance, failed to anticipate China’s economic growth, or resistance by the United States and other nations to curbing greenhouse gases.

“We really haven’t explored a world in which the emissions growth rate is as rapid as we have actually seen happen,” Fields said.

Temperature

IPCC models use the emission scenarios discussed above to estimate average global temperature increases by the year 2100.

warming-300

Projection: The IPCC 2007 assessment projected a worst-case temperature rise of 4.3° to 11.5° Fahrenheit, with a high probability of 7.2°F.

Reality: We are currently on track for a rise of between 6.3° and 13.3°F, with a high probability of an increase of 9.4°F by 2100, according to the Massachusetts Institute of Technology. Other modelers are getting similar results, including a study published earlier this month by the Global Carbon Project consortium confirming the likelihood of a 9ºF rise.

Why the miss? IPCC emission scenarios underestimated global CO2 emission rates, which means temperature rates were underestimated too. And it could get worse: IPCC projections haven’t included likely feedbacks such as large-scale melting of Arctic permafrost and subsequent release of large quantities of CO2 and methane, a greenhouse gas 20 times more potent, albeit shorter lived, in the atmosphere than carbon dioxide.

Arctic Meltdown

Five years ago, the summer retreat of Arctic ice wildly outdistanced all 18 IPCC computer models, amazing IPCC scientists. It did so again in 2012.

ice-600

Projection: The IPCC has always confidently projected that the Arctic ice pack was safe at least until 2050 or well beyond 2100.

Reality: Summer ice is thinning faster than every climate projection, and today scientists predict an ice-free Arctic in years, not decades. Last summer, Arctic sea ice extent plummeted to 1.32 million square miles, the lowest level ever recorded – 50 percent below the long-term 1979 to 2000 average.

Why the miss? For scientists, it is increasingly clear that the models are under-predicting the rate of sea ice retreat because they are missing key real-world interactions.

“Sea ice modelers have speculated that the 2007 minimum was an aberration… a matter of random variability, noise in the system, that sea ice would recover.… That no longer looks tenable,” says IPCC scientist Michael Mann. “It is a stunning reminder that uncertainty doesn’t always act in our favor.”

Ice Sheets

Greenland and Antarctica are melting, even though IPCC said in 1995 that they wouldn’t be.

Projection: In 1995, IPCC projected “little change in the extent of the Greenland and Antarctic ice sheets… over the next 50-100 years.” In 2007 IPCC embraced a drastic revision: “New data… show[s] that losses from the ice sheets of Greenland and Antarctica have very likely contributed to sea level rise over 1993 to 2003.”

Today, ice loss in Greenland and Antarctica is trending at least 100 years ahead of projections compared to IPCC’s first three reports.

Reality: Today, ice loss in Greenland and Antarctica is trending at least 100 years ahead of projections compared to IPCC’s first three reports.

Why the miss? “After 2001, we began to realize there were complex dynamics at work – ice cracks, lubrication and sliding of ice sheets,” that were melting ice sheets quicker, said IPCC scientist Kevin Trenberth. New feedbacks unknown to past IPCC authors have also been found. A 2012 study, for example, showed that the reflectivity of Greenland’s ice sheet is decreasing, causing ice to absorb more heat, likely escalating melting.

Sea-Level Rise

The fate of the world’s coastlines has become a classic example of how the IPCC, when confronted with conflicting science, tends to go silent.

Projection: In the 2001 report, the IPCC projected a sea rise of 2 millimeters per year. The worst-case scenario in the 2007 report, which looked mostly at thermal expansion of the oceans as temperatures warmed, called for up to 1.9 feet of sea-level-rise by century’s end.

Today: Observed sea-level-rise has averaged 3.3 millimeters per year since 1990. By 2009, various studies that included ice-melt offered drastically higher projections of between 2.4 and 6.2 feet sea level rise by 2100.

Why the miss? IPCC scientists couldn’t agree on a value for the contribution melting Greenland and Antarctic ice sheets would add to sea-level rise. So they simply left out the data to reach consensus. Science historian Naomi Oreskes calls this – one of IPCC’s biggest underestimates – “consensus by omission.”

Ocean Acidification

To its credit, the IPCC admits to vast climate change unknowns. Ocean acidification is one such impact.

Projection: Unmentioned as a threat in the 1990, 1995 and 2001 IPCC reports. First recognized in 2007, when IPCC projected acidification of between 0.14 and 0.35 pH units by 2100. “While the effects of observed ocean acidification on the marine biosphere are as yet undocumented,” said the report, “the progressive acidification of oceans is expected to have negative impacts on marine shell-forming organisms (e.g. corals) and their dependent species.”

Reality: The world’s oceans absorb about a quarter of the carbon dioxide humans release annually into the atmosphere. Since the start of the Industrial Revolution, the pH of surface ocean waters has fallen by 0.1 pH units. Since the pH scale is logarithmic, this change represents a stunning 30 percent increase in acidity.

Why the miss? Scientists didn’t have the data. They began studying acidification by the late 1990s, but there weren’t many papers on the topic until mid-2000, missing the submission deadline for IPCC’s 2001 report. Especially alarming are new findings that ocean temperatures and currents are causing parts of the seas to become acidic far faster than expected, threatening oysters and other shellfish.

National Oceanic and Atmospheric Administration chief Jane Lubchenco has called acidification the “equally evil twin” to global warming.

Thawing Tundra

Some carbon-cycle feedbacks that could vastly amplify climate change – especially a massive release of carbon and methane from thawing permafrost – are extremely hard to model.

Projection: In 2007, IPCC reported with “high confidence” that “methane emissions from tundra… and permafrost have accelerated in the past two decades, and are likely to accelerate further.” However, the IPCC offered no projections regarding permafrost melt.

Reality: Scientists estimate that the world’s permafrost holds 1.5 trillion tons of frozen carbon. That worries scientists: The Arctic is warming faster than anywhere else on earth, and researchers are seeing soil temperatures climb rapidly, too. Some permafrost degradation is already occurring.

Large-scale tundra wildfires in 2012 added to the concern.

Why the miss? This is controversial science, with some researchers saying the Arctic tundra is stable, others saying it will defrost only over long periods of time, and still more convinced we are on the verge of a tipping point, where the tundra thaws rapidly and catastrophically. A major 2005 study, for instance, warned that the entire top 11 feet of global permafrost could disappear by century’s end, with potentially cataclysmic climate impacts.

The U.N. Environmental Programme revealed this week that IPCC’s fifth assessment, due for release starting in September, 2013, will again “not include the potential effects of the permafrost carbon feedback on global climate.”

Tipping points

The IPCC has been silent on tipping points – non-linear “light switch” moments when the climate system abruptly shifts from one paradigm to another.

The trouble with tipping points is they’re hard to spot until you’ve passed one.

Projection: IPCC has made no projections regarding tipping-point thresholds.

Reality: The scientific jury is still out as to whether we have reached any climate thresholds – a point of no return for, say, an ice-free Arctic, a Greenland meltdown, the slowing of the North Atlantic Ocean circulation, or permanent changes in large-scale weather patterns like the jet stream, El Niño or monsoons. The trouble with tipping points is they’re hard to spot until you’ve passed one.

Why the miss? Blame the computers: These non-linear events are notoriously hard to model. But with scientists recognizing the sizeable threat tipping points represent, they will be including some projections in the 2013-14 assessment.

Correction (Dec. 6, 2012): Earlier editions incorrectly compared global carbon dioxide emissions against carbon emissions scenarios. Carbon dioxide is heavier, incorrectly skewing the comparison. Global use of fossil fuels in 2010 produced about 30 billion tons of carbon dioxide but only 9.1 tons of carbon, putting emissions within the extreme end of IPCC scenarios. The story has been changed to reflect that.

Graphic of emissions scenario courtesy U.S. Global Change Research Program. Photo of activist warning of 6ºC warming © Adela Nistora. Graphic showing Arctic summer ice projections vs. observations by the Vancouver Observer.

Glenn Scherer is senior editor of Blue Ridge Press, a news service that has been providing environmental commentary and news to U.S. newspapers since 2007.

DailyClimate.org is a foundation-funded news service covering climate change. Contact editor Douglas Fischer at dfischer [at] dailyclimate.org

Scientists Pioneer Method to Predict Environmental Collapse (Science Daily)

17/12/2012UncategorizedClima, Incerteza, Mediação tecnológica, Meteorologia, Modelagem, Mudanças climáticas, Previsãorenzotaddei

Researcher Enlou Zhang takes a core sample from the bed of Lake Erhai in China. (Credit: University of Southampton)

Nov. 19, 2012 — Scientists at the University of Southampton are pioneering a technique to predict when an ecosystem is likely to collapse, which may also have potential for foretelling crises in agriculture, fisheries or even social systems.

The researchers have applied a mathematical model to a real world situation, the environmental collapse of a lake in China, to help prove a theory which suggests an ecosystem ‘flickers’, or fluctuates dramatically between healthy and unhealthy states, shortly before its eventual collapse.

Head of Geography at Southampton, Professor John Dearing explains: “We wanted to prove that this ‘flickering’ occurs just ahead of a dramatic change in a system — be it a social, ecological or climatic one — and that this method could potentially be used to predict future critical changes in other impacted systems in the world around us.”

A team led by Dr Rong Wang extracted core samples from sediment at the bottom of Lake Erhai in Yunnan province, China and charted the levels and variation of fossilised algae (diatoms) over a 125-year period. Analysis of the core sample data showed the algae communities remained relatively stable up until about 30 years before the lake’s collapse into a turbid or polluted state. However, the core samples for these last three decades showed much fluctuation, indicating there had been numerous dramatic changes in the types and concentrations of algae present in the water — evidence of the ‘flickering’ before the lake’s final definitive change of state.

Rong Wang comments: “By using the algae as a measure of the lake’s health, we have shown that its eco-system ‘wobbled’ before making a critical transition — in this instance, to a turbid state.

“Dramatic swings can be seen in other data, suggesting large external impacts on the lake over a long time period — for example, pollution from fertilisers, sewage from fields and changes in water levels — caused the system to switch back and forth rapidly between alternate states. Eventually, the lake’s ecosystem could no longer cope or recover — losing resilience and reaching what is called a ‘tipping point’ and collapsing altogether.”

The researchers hope the method they have trialled in China could be applied to other regions and landscapes.

Co-author Dr Pete Langdon comments: “In this case, we used algae as a marker of how the lake’s ecosystem was holding-up against external impacts — but who’s to say we couldn’t use this method in other ways? For example, perhaps we should look for ‘flickering’ signals in climate data to try and foretell impending crises?”

Journal Reference:

Rong Wang, John A. Dearing, Peter G. Langdon, Enlou Zhang, Xiangdong Yang, Vasilis Dakos, Marten Scheffer.Flickering gives early warning signals of a critical transition to a eutrophic lake state. Nature, 2012; DOI:10.1038/nature11655