The Guardian

World’s forests can adapt to climate change
The Guardian

It is generally acknowledged that a warming world will harm the world’s forests. Higher temperatures mean water becomes more scarce, spelling death for plants – or perhaps not always.

According to a study of ancient rainforests, trees may be hardier than previously thought. Carlos Jaramillo, a scientist at the Smithsonian Tropical Research Institute, 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. »

In a study published todayin 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. The study also shows moisture levels did not decrease significantly during the warm period.

Last year, researchers at the Met Office Hadley Centre reported that a 2C rise above pre-industrial levels, widely considered the best-case scenario, 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 in the next century, while a 4C rise would kill 85%.