"The environmental crisis (leads me to) conclude that I have not gone nearly far enough. The time has long since come to take more political risks ... We must make the rescue of the environment the central organizing principle for civilization ... We can believe in (the) future and work to preserve it, or we can whirl blindly on, behaving as if one day there will be no children to inherit our legacy. The choice is ours; the earth is in the balance."
Al Gore, "Earth in the Balance"
Amazon hit by worst drought for 40 years
Read the entire article at: http://www.nature.com/news/2005/051010/pf/051010-8_pf.html
Parts of the Amazon rainforest are enduring the worst drought for 40 years, prompting local government to declare several cities in the Brazilian state of Amazonas as disaster areas.
Researchers say that rising sea temperatures in the North Atlantic, perhaps prompted by climate change, are probably to blame. In addition, Researchers at a forest monitoring station in Santarém, where the Amazon and Tapajós rivers meet, report that water levels are some 15 metres lower than usual.
"Everybody has been taken by surprise," says Paul Lefebvre, a researcher at the Woods Hole Research Center in Massachusetts, which runs the station. Droughts in South America are often associated with El Niño climate events - oscillating changes to weather patterns that occur as a result of periodic warming of southern Pacific waters. But researchers have not spotted any such warming this year, Lefebvre says.
Instead, rising surface temperatures in the North Atlantic could be the culprit. The waters have been unusually warm this year - as shown to devastating effect by this year's unusually destructive tropical hurricane season. This creates storm conditions that carry water and energy towards the United States. But it also sets up high pressure systems over neighbouring regions further south, such as the Amazon.
Drought in the Amazon could also stunt tree growth and make the forest more susceptible to burning - both of which could have global implications for climate. Studies by Lefebvre's colleagues show that drought conditions can cut the amount that trees grow by a quarter, which would in theory prevent the forest's ability to soak up carbon. If this happens, the Amazon could conceivably become a carbon 'source', pumping out carbon dioxide faster than it can absorb it, Lefebvre says. More carbon dioxide in the atmosphere could raise world temperatures even further, making droughts even more damaging in the future.
The ultimate fear is that the Amazon forest - often touted as an invaluable piece of armour against climate change - could become part of the problem rather than a key element of the solution.
Summarized by Copernic Summarizer