Global warming will wreck attempts to save the Amazon rainforest, according to a devastating new study which predicts that one-third of its trees will be killed by even modest temperature rises. . .The Guardian (U.K.), November 11, 2010:
The study, which has been submitted to the journal Nature Geoscience, used computer models to investigate how the Amazon would respond to future temperature rises.
It found that a 2C rise above pre-industrial levels, widely considered the best case global warming scenario and the target for ambitious international plans to curb emissions, would still see 20-40% of the Amazon die off within 100 years. A 3C rise would see 75% of the forest destroyed by drought over the following century, while a 4C rise would kill 85%.
According to a study of ancient rainforests, trees may be hardier than previously thought. Carlos Jaramillo, a scientist at the Smithsonian Tropical Research Institute (STRI), examined pollen from ancient plants trapped in rocks in Colombia and Venezuela. "There are many climactic models today suggesting that . . . if the temperature increases in the tropics by a couple of degrees, most of the forest is going to be extinct," he said. "What we found was the opposite to what we were expecting: we didn't find any extinction event [in plants] associated with the increase in temperature, we didn't find that the precipitation decreased."Conclusion: "Unexpected" means climate change science isn't settled. Remember that when considering the U.N. push for global taxation (!) to raise $100 billion for "climate financing."
In a study published today in Science, Jaramillo and his team studied pollen grains and other biological indicators of plant life embedded in rocks formed around 56m years ago, during an abrupt period of warming called the Paleocene-Eocene Thermal Maximum. CO2 levels had doubled in 10,000 years and the world was warmer by 3C-5C for 200,000 years.
Contrary to expectations, he found that forests bloomed with diversity. New species of plants, including those from the passionflower and chocolate families, evolved quicker as others became extinct. The study also shows moisture levels did not decrease significantly during the warm period. "It was totally unexpected," Jaramillo said of the findings.
(via Watts Up With That?)