Climate - Nov 7
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The Price of Climate Change
Stephen J. Dubner and Steven D. Levitt, New York Times
The famous old quip about the weather - everyone talks about it but nobody does anything about it - is not as true as it once was. Alarmed by the threat of global warming, lots of people are actively trying to change human behaviors in order to change the weather.
Even economists are getting into the weather business. Olivier Deschênes of the University of California at Santa Barbara and Michael Greenstone of the Massachusetts Institute of Technology have written a pair of papers that assess some effects of climate change. In the first, they use long-run climatological models - year-by-year temperature and precipitation predictions from 2070 to 2099 - to examine the future of agriculture in the United States. Their findings? The expected rises in temperature and precipitation would actually increase annual agricultural production, and therefore agricultural profits, by about 4 percent, or $1.3 billion. This hardly fulfills the doomsday fears conjured by most conversations about global warming.
(5 Nov 2006)
It should be noted that these projections come from economists rather than climate or agricultural scientists. Some other reports are not as optimistic:
- Study shows global warming may not lead to greater crop yields
- Global warming could make Canada an agricultural powerhouse while the U.S. becomes a dustbowl
The rest of the article includes an interesting look at how weather can ultimately affect behaviour, taking the example of rainfall and levels of violence. Deschenes and Greenstone have also attempted an estimation about how climate change might affect death rate in the U.S. and then translate that into cost to the economy. -AF
The U.S. is the leading emitter of greenhouse gases and the worst effects of global warming will be felt in poor countries (see following article). -BA
Africans are already facing climate change
Scott Baldauf, Christian Science Monitor
Is Darfur the first climate-change conflict? In Kenya, a UN meeting begins Monday to set new fossil-fuel emissions targets.
JOHANNESBURG, SOUTH AFRICA - As delegates gather Monday in Kenya for a United Nations conference to set new targets to reduce fossil-fuel emissions after 2012, climate change is a present reality for many Africans.
In Kenya, Sudan, Ethiopia, Somalia, and Chad, people are already seeing the repercussions - including war. The conflict between herders and farmers in Sudan's Darfur region, where farm and grazing lands are being lost to desert, may be a harbinger of the future conflicts.
"You have climate change and reduced rainfall and shrinking areas of arable land; and then you add population growth and you have the elements of an explosion," says Francis Kornegay, a senior analyst at the Center for Policy Studies in Johannesburg.
On Sunday, a new UN report predicted that by 2080, global warming could lead to a 5 percent fall in the production of food crops, such as sorghum in Sudan, Ethiopia, Eritrea, and Zambia; maize in Ghana; millet in Sudan; and groundnuts in Gambia.
Between 25 percent and 40 percent of Africa's natural habitats could be lost by 2085, according to the report produced by the Secretariat of the UN Framework Convention on Climate Change (UNFCCC). It also said that rising sea levels could destroy an estimated 30 percent of Africa's coastal infrastructure. Coastal settlements in the Gulf of Guinea, Senegal, Gambia, and Egypt could be flooded,
Ironically, Africa produces the smallest amount of the greenhouse gases blamed for climate change.
(6 Nov 2006)
Grist has links to related stories.
Aust experiencing worst drought in 1,000 years, summit told
Australian Broadcasting Corp.
Federal and state leaders have been told Australia is experiencing the worst drought in a 1,000 years.
Today's emergency water summit has brought forward an interstate water trading scheme and extended drought relief to small businesses in affected areas.
The Murray Darling Basin Commission briefed the leaders on the extent of the drought and South Australia's Premier Mike Rann calls it a frightening glimpse of the future.
"That was a very critical point made today that the Commission now believes that this is a one in 1,000 year drought and that means that we all have to work together," he said.
But Greens Senator Rachel Siewert says the summit has not achieved enough.
"What we've seen today is a talkfest," she said.
(7 Nov 2006)
In Ancient Fossils, Seeds of a New Debate on Warming
William J. Broad, The New York Times
In recent years, scientists have made sizable gains in what was once considered an impossible art - reconstructing the history of Earth’s atmosphere back into the dim past. They can now peer across more than a half billion years.
The scientists have learned about the changing makeup of the vanished gases by teasing subtle clues from fossilized soils, plants and sea creatures. They have also gained insights from computer models that predict how phenomena like eroding rocks and erupting volcanoes have altered the planet’s evolving air. “It’s getting a lot more attention,” Michael C. MacCracken, chief scientist of the Climate Institute, a research group in Washington, said of the growing field.
For the first time, the Intergovernmental Panel on Climate Change, a United Nations group that analyzes global warming, plans to include a chapter on the reconstructions in its latest report, due early next year.
The discoveries have stirred a little-known dispute that, if resolved, could have major implications. At issue is whether the findings back or undermine the prevailing view on global warming. One side foresees a looming crisis of planetary heating; the other, temperature increases that would be more nuisance than catastrophe.
(7 Nov 2006)
It's worth checking out the graph associated with this article. William Broad rather unfairly states that "Most public discussions of global warming concentrate on evidence from the last few hundred or, at most, few thousand years." He later mentions the ice core data which goes back around half a million years. This is not long compared to the timescales of 500 million years shown talked about in this article, however it is the most relevant half a million years, when solar radiation, the biosphere and plate tectonics were most like they are today. -AF
Idea that forests are 'carbon sinks' going down drain
Tom Spears, CanWest News Service
OTTAWA - Canadians rely partly on our nation's forests to help save the world's climate. Now evidence says it's time to stop.
In Canada we know we burn too much coal, gas and oil, creating the "greenhouse'' gas called carbon dioxide.
But we have learned for years that in the fight against climate change, this country's vast forests too many trees to count pull carbon dioxide out of the air again, locking it up as solid carbon in branches, roots and trunks.
Just one problem, scientists now say. It's largely wrong.
Even as the federal government is poised to argue that our trees should reduce our Kyoto obligations, scientists say these supposed saviours have done about all they can to prevent global warming.
Forests can do little to improve the future climate or to lower the atmosphere's carbon levels. What they can do is make global warming worse.
...But what about all the other forests, the southern ones with their maple-beech-oak hardwoods, and their pines and aspens? Aren't they cleaning our air?
Unfortunately, said, Bill Schlesinger of Duke University, even these forests are generally in a steady state in terms of carbon production and sequestration.
``And so you can't really count on them as a big sink,'' he said.
Yes, he acknowledges, many people do make the claim that forests will counteract our car-driving, coal-burning ways.
``Oil and coal companies love to say that. So do various forest services,'' he said. ``It sort of gives them a raison d'etre.
``But the idea that they're going to combat the rise of CO2 in the atmosphere has, I think, probably been overstated. If you disturb them,'' by cutting them down or burning them, ``then they may exacerbate the rise of carbon dioxide.
(5 Nov 2006)
A good point, but rather awkwardly put. As I understand it, existing forests do not add or subtract carbon dioxide on average. What does affect levels of carbon dioxide is the planting or destruction of forests. For example, the Stern Review mentions that "deforestation is responsible for more emissions than the transport sector." -BA
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