Monday, May 07, 2007

Enviro: North America: Carbon sink, Arctic ice melt, polar bears

Peter N. Spotts on Nature's 'carbon sink' in CSM, "Nature's carbon 'sink' smaller than expected--Earth in 2100 could be up to 2.7 degrees F. hotter than previously predicted, studies say." (May3,2k7):

When it comes to global warming, nature's help is limited.

While the continents and oceans have absorbed much of the carbon dioxide that humanity has pumped into the atmosphere so far, they won't be able to keep up with the expected rise in greenhouse-gas emissions over the next several decades. Indeed, some recent studies suggest that current scientific estimates about natural absorption are too optimistic: Earth's climate by century's end could be on average up to 1.5 degrees C (2.7 degrees F.) hotter than current "business as usual" projections suggest.

What this implies is that policy and technological measures to cope with climate change will become even more important. This week, scientists and government negotiators are wrestling over those measures in a key international meeting in Bangkok, Thailand. They will lay out their recommendations in a summary statement slated for release Friday.

"We've been getting a free ride from forests and oceans," says Robert Jackson, a Duke University ecologist who heads the southeastern division of the US Department of Energy's National Institute for Climate Change Research. But "I'm not confident – especially as our fossil-fuel emissions continue to grow – that we can rely on natural systems to bail us out of this."

To be sure, few if any in the climate-policy community advocate a hands-off, let-nature-do-it-all approach. But the use of natural "sinks" – oceans, plants, and soil that can hold carbon – is said to appear in the report researchers and politicians are haggling over this week.
Gregory M. Lamb on Arctic Melt-off, "Arctic melt-off: ahead of schedule--A new analysis shows that well before the century's end, it could be ice-free for part of the year (May3, 2k7).
Hundreds of scientists and government officials from around the world are meeting in Bangkok, preparing to issue a May 4 report on what steps should be taken to combat global warming. But a new study released May 1 showed that one of the group's predictions on climate change, made in an earlier February report, may already be too conservative.

The Intergovernmental Panel on Climate Change (IPPC) had said that Arctic sea ice was shrinking by as much as 5.4 percent per decade. At that rate, it could disappear entirely toward the end of this century.
Enviroment > North America
But new analysis from scientists at the National Center for Atmospheric ResearchM and the National Snow and Ice Data Center (NSIDC), both in Boulder, Colo., shows that the rate from 1953 to 2006 was more like 7.8 percent per decade. The earlier IPCC models suggested that about half the polar melting was due to global warming. The NSIDC study says greenhouse gases may play an even more significant role.
Fred Langan on Polar Bears, "Canadian controversy: How do polar bears fare?--Despite global warming, an ongoing study says polar bear populations are rising in the country's eastern Arctic region" (May3,2k7).
Polar bears are the poster animals of global warming. The image of a polar bear floating on an ice floe is one of the most dramatic visual statements in the fight against rising temperatures in the Arctic.

But global warming is not killing the polar bears of Canada's eastern Arctic, according to one ongoing study. Scheduled for release next year, it says the number of polar bears in the Davis Strait area of Canada's eastern Arctic – one of 19 polar bear populations worldwide – has grown to 2,100, up from 850 in the mid-1980s.

"There aren't just a few more bears. There are a ... lot more bears," biologist Mitchell Taylor told the Nunatsiaq News of Iqaluit in the Arctic territory of Nunavut. Earlier, in a long telephone conversation, Dr. Taylor explained his conviction that threats to polar bears from global warming are exaggerated and that their numbers are increasing. He has studied the animals for the Nunavut government for two decades.

Updates from the study by Taylor and his team have received significant media coverage in Canada, shaking the image of the polar bear as endangered.
I usually trust Christian Science Monitor reportage, but there's an unjustified slant running thru all these articles. They're worth clicking-up and reading in their entirety, but they shed no lite on the models of forecasting, especially in the first two articles. In the third, a controversy forces a fairer balancing than in the others. What we should realize is that all the sources have vested interests, and in no case is the science in a state of unanimity. We should get more disinterested assessment of the interests of each source, like factoring in among the truth-possibliities of a sources "scientific claim" the competition for funding of whole institutes in their bid to surpass the money raised by other institutes (money that comes usually from governments or UN agencies). All the major forecasting models are full of unexamined assumptions, and resemble the poor polar bear in the poster of the enviro-scam industry (chiefly NGOs bilking the public more directly than do university-related research units feeding off tax-payers).

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