Dear earthlings:
It doesn’t do you any good to get all excited about finding earth-like planets like Kepler 22-B where the average temperature is 72 degrees F (22 C.), if you are going to turn your own planet into a sweltering tropical swamp.

The Durban climate conference about the fate of our own planet has been a miserable failure. Even China’s surprise announcement of willingness to talk about binding emissions limits is less than meets the eye. We are on track for a rise in average temperatures of some 5 degrees Celsius, something the earth hasn’t experienced since the Eocene 50 million years ago (when there was no surface ice and the world was tropical to the poles, and a third more of the land mass was under water).
It is all very well to wax poetic over earth-like planets out there, but let’s try to keep this one earthlike.