...the global surface albedo [surface whiteness] and greenhouse gas changes account for practically the entire global climate change.
James HansenA level of no more than 350 ppm is still feasible, with the help of reforestation and improved agricultural practices, but just barely - time is running out.
James HansenWe have to, in the next ten years, begin to decrease the rate of carbon dioxide emissions and then flatten it out. If that doesn't happen in ten years, we're going to be passing certain tipping points. If the ice sheets begin to disintegrate, what can you do about it? You can't tie a rope around an ice sheet.
James Hansen