Climate-change alarmists have warned for years that rising temperatures they associate with higher levels of CO2 would radically reduce the Amazonian rainforests as water got more scarce.  The argument was that the heat would reduce the rainfall, which would eventually turn the rainforests into savannahs or even dust bowls and seriously impact oxygen and climate patterns for the entire world.  Now a new study, reported by the Guardian — hardly a bastion of skepticism on AGW claims — says both predictions are entirely incorrect (via QandO):

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.”

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.

When water became more scarce, the plants started becoming more efficient at its use.  The changes in temperature not only didn’t kill off the trees, it led to an explosion of diversity, which once again poses the question of whether anyone actually understands these systems enough to reach a conclusion on what exactly the optimal temperature is for the planet.  These findings seem to suggest that our period may be a little on the cool side for natural diversity and agricultural production.

Or, more accurately, that the AGW science is mainly conjectural in the first place.  The lack of certainty in the speculative horror stories spun by the IPCC and its already-busted myths, combined with the utter failure of AGW models to accurately predict any outcomes, should already have had most people skeptical of the entire exercise.  Now we find out that 200,000 years of climate 5C warmer than this period not only didn’t turn the Earth into a barren desert but instead led to adaptations, strength, and an explosion of diversity, setting the stage for the expansion of humans on the planet.

The study’s authors conclude that warming presents little threat to the rainforest, and instead advises activists to focus on fighting deforestation instead.  That is, at least, a legitimate threat to the existence of the rainforests, and an issue with a lot more credibility than the Chicken Little scenarios that hysterical AGW activists keep spinning.