Arquivo mensal: março 2013

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

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.

Anúncios

The Crisis in Climate-Change Coverage (Truth Out)

Sunday, 03 March 2013 07:23

By Josh StearnsFree Press

Climate activist Bill McKibben speaking at the San Francisco Bay Area's Moving Planet rally. (Photo: <a href="http://www.flickr.com/photos/350org/6186391697/sizes/m/in/photostream/" target="_blank"> 350.org / flickr</a>)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.

The interspecies internet: Diana Reiss, Peter Gabriel, Neil Gershenfeld and Vint Cerf at TED2013 (TED)

Posted by: Kate Torgovnick 

February 28, 2013 at 8:13 pm EST

Photos: James Duncan Davidson
Photos: James Duncan Davidson

The internet connects people all over the world. But could the internet also connect us with dolphins, apes, elephants and other highly intelligent species?

In a bold talk in Session 10 of TED2013, four incredible thinkers come together to launch the idea of the interspecies internet. Each takes four minutes to talk, then passes the metaphorical baton, building the narrative in parts.

The talk begins with Diana Reiss, a cognitive psychologist who studies intelligence in animals. She shows us a video of an adorable dolphin twirling in the water. But the dolphin isn’t spinning playfully for the camera — the dolphin is watching itself in a two-way mirror.

“A dolphin has self-awareness,” says Reiss. “We used to think this was a uniquely human quality, but dolphins aren’t the only non-human animals to show self-recognition in a mirror. Great apes, our closest relatives, also show this ability.” Ditto for elephants and even magpies.

Reiss shares her work with dolphins — she’s been teaching them to communicate through an underwater keyboard of symbols that correspond to whistles and playful activities. Through this keyboard, the dolphins learned to perform activities on demand, and also to express their desire for them. (For more on how a similar dolphin keyboard works, read up on Denise Herzing’s talk from earlier today.)

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“You can’t get more alien than the dolphin. We’re separated by 95 million years of divergent evolution. These are true non-terrestrials,” says Reiss. “This self-organized learning, the same thing we heard from TED Prize winner Sugata Mitra. I’m suggesting this is our Hole in the Water.”

Reiss was conducting this work on her own. And then she got a call from iconic musician Peter Gabriel.

“I make noises for a living, and on a good day it’s music,” says Gabriel. He has always looked into the eyes of animals and wondered what is going on inside their heads, he says, soe excitedly read about research, like Reiss’, examining communication with animals.

“What was amazing to me was that [the animals] seemed a lot more adept at getting a handle on our language than we were at getting a handle on theirs,” says Gabriel. “I work with a lot of musicians from around the world. Often we don’t have any common language at all. We sit behind our instruments and it’s a way to connect.”

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So Gabriel started cold-calling scientists to see if he could be a part of this work. His goal: To try writing music with an animal. And he got his chance.

In a video clip that raises oohs and ahhs from audience, Gabriel shares a video of a bonobo with a keyboard. While bonobos had been introduced to percussion instruments before, and bashed them with their fists, this was the first time this bonobo had ever seen a keyboard. And with accompaniment, she played truly amazing music.

“She discovers a note she likes. She finds the octave,” says Gabriel, narrating the beautiful melody in the video. “We began to dream … What would happen if we could somehow find new interfaces – visual, audio — to allow us to communicate with the remarkable beings we share the planet with.”

Gabriel brought the video of this unusual jam session to Neil Gershenfeld, the Director of MIT’s Center for Bits and Atoms.

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“I lost it when I saw that clip,” says Gershenfeld, stepping up to the stage. “I was struck by the history of the internet, because it started as the internet of middle-aged white men … I realized that we humans had missed something — the rest of the planet.”

At this point, Gershenfeld video-conferenced in animals live — including orangutans in Waco, Texas, dolphins at the National Aquarium in Baltimore, and elephants in Thailand.

Gershenfeld is known for his work in the internet of things. And he thinks animals can be a part of it, too. ”We’re starting to think about how you integrate the rest of the biomass of the planet into the internet,” he says.

Which brings us to Vint Cerf, who helped lay the foundations for the internet as we know it and is now vice president and Chief Internet Evangelist for  Google.

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“Forty years ago we wrote the script of the internet. Thirty years ago we turned it on,” says Cerf. “We thought we were building a system to connect computers together. But we quickly learned that it’s a system for connecting people.”

“You know where this is going,” Cerf continues, to a laugh, bringing it back to research in communicating with animals. ”What’s important about what these people are doing: They’re beginning to learn how to communicate with species that are not us, but share a sensory environment. [They’re figuring out] what it means to communicate with something that’s not a person. I can’t wait to see these experiments unfold.”

So what’s next? The internet of things, yes, and the ability for us to communicate with computers without keyboards and mice. And in addition to the internet of species, he even imagines an interplanetary internet.

“These interactions with other animals will teach us, ultimately, how we might interact with an alien from another world,” says Cerf. “I can hardly wait.”

Appeals court rules U.S. whaling foes are ‘pirates’ (USA Today)

Michael Winter, USA TODAY- 7:35p.m. EST February 27, 2013

Sea Shepherd activists have collided with Japanese ships in campaign to halt whale hunts.

A federal appeals court has declared the Sea Shepherd Conservation Society to be modern-day pirates and ordered the anti-whaling activists to stop confronting Japanese ships in the waters off Antarctica.

A three-judge panel of the 9th U.S. Circuit Court of Appeals reversed and rebuked a lower-court judge in Seattle, who had sided with Washington state-based Sea Shepherd and dismissed a lawsuit filed by Japanese whalers seeking to halt the protests. An international treaty allows governments to kill whales for research.

In its ruling late Monday, the appeals court also ordered U.S. District Judge Richard Jones removed from the case, saying “numerous, serious and obvious errors identified in our opinion raise doubts as to whether he will be perceived as impartial.”

Sea Shepherd ships, sailing from Australia, often block or harass whaling vessels from the Institute of Cetacean Research, sometimes resulting in collisions. During the past week, two of the group’s vessels were damaged while trying to prevent Japanese whaling vessels from refueling.

In the appellate court’s ruling, Chief Judge Alex Kozinski wrote that the activists were threatening the lives of whalers, calling their tactics “the very embodiment of piracy.”

Here’s how he began the 18-page opinion:

You don’t need a peg leg or an eye patch. When you ram ships; hurl glass containers of acid; drag metal-reinforced ropes in the water to damage propellers and rudders; launch smoke bombs and flares with hooks; and point high-powered lasers at other ships, you are, without a doubt, a pirate, no matter how high-minded you believe your purpose to be.

Kozinski wrote that Jones was “off base” when he concluded that the protesters’ tactics were nonviolent because they did not target people, just ships and equipment.

Jones also ruled that the hunters were violating an Australian court ban and therefore could not pursue their lawsuit in the United States. The appeals court rejected that argument, saying the whalers’ lawsuit could proceed in U.S. courts under international maritime law.

An attorney representing Sea Shepherd told the Associated Press he would ask an 11-judge panel of the appeals court to review the three-judge opinion.

A Sea Shepherd official told KIRO Radio on Tuesday that because the U.S. branch had separated from its Australian counterparts, the ruling had no bearing.

“What Sea Shepherd Australia is doing with Australian flagged vessels and Dutch flagged vessels down in the Australian Antarctic territory is outside of any sort of control of the courts in the United States,” said Scott West, director of investigations for Sea Shepherd. “We have yet to hurt anybody, we have yet to plunder any gold or do anything that would fit within the definition” of piracy law.

Sea Shepherd Australia released video that it said showed a Japanese whalerramming two of its ships last week. Tuesday, the ICR countered with video that it claims shows Sea Shepherd “sabotage” by ramming a whaling vessel.

Sea Shephred’s efforts have been featured on Animal Planet’s Whale Wars.