ScienceDaily: Tropical rainforests are often called the "lungs of the planet" because they generally draw in carbon dioxide and breathe out oxygen. But the amount of carbon dioxide that rainforests absorb, or produce, varies hugely with year-to-year variations in the climate. In a paper published online Feb 6 2013 by the journal Nature, a team of climate scientists from the University of Exeter, the Met Office-Hadley Centre and the NERC Centre for Ecology & Hydrology, has shown that these variations reveal...