Nature: One of the wild cards in climate change is the fate of the Amazon rainforest. Will it shrivel as the region dries in a warming climate? Or will it grow even faster as the added carbon dioxide in the atmosphere spurs photosynthesis and allows plants to use water more efficiently? A dying rainforest could release gigatonnes of carbon into the atmosphere, accelerating warming; a CO2-fertilized forest could have the opposite effect, sucking up carbon and putting the brakes on climate change.
Climate...