Reuters: The Amazon rainforest's ability to soak up greenhouse gases from the air has fallen sharply, possibly because climate change and droughts mean more trees are dying, an international team of scientists said on Wednesday. The world's biggest rainforest has soaked up vast amounts of carbon dioxide. Plants use the heat-trapping gas to grow and release it when they rot or burn, but the report said that role in offsetting global warming may be under threat. The study, of 321 plots in parts of the Amazon...