The most important work I did this year was a paper about the Earth’s energy imbalance. Using data from floats in the ocean that monitor water temperature, we’ve shown that the planet is out of balance by about six-tenths of a watt. This means there’s more energy coming in from the sun than there is heat energy being radiated outward into space. It means that even if we stopped emitting CO2 today, the planet will continue to warm up until it establishes an energy balance.
James Hansen, NASA climate-change scientist and political activist.