We've been following James Hansen quite closely on this site when it comes to Climate Change. As head of NASA’s Goddard Institute for Space Studies he has a proven track record as a scientist and has even been arrested outside the White House so he's not averse to putting himself on the line for his views. In a recent short publication called "Butterfly Report + Jeremiah, the Frog" he is surprisingly upbeat. Steering a narrow pathway between "gloom and doom" naysayers and climate change deniers he says "The picture for the future is actually very bright, if the necessary people wake up to the situation soon."
Read the full letter here