WASHINGTON, DC.- The steamiest places on the planet are getting warmer. Conservative estimates suggest that tropical areas can expect temperature increases of 3 degrees Celsius by the end of this century. Does global warming spell doom for rainforests? Maybe not. Carlos Jaramillo, staff scientist at the Smithsonian Tropical Research Institute, and colleagues report in the journal Science that nearly 60 million years ago rainforests prospered at temperatures that were 3–5 degrees higher and at atmospheric carbon dioxide levels 2.5 times today’s levels. “We’re going to have a novel climate scenario,” said Joe Wright, staff scientist at STRI, in a 2009 Smithsonian symposium on Threats to Tropical Forests. “It will be very hot and wet, and we don’t know how these species are going to react.” By looking back in time, Jaramillo and collaborators identified one example of a hot, wet climate: rainforests were doing very well. Researchers examined