A broad scientific census says that Earth is already experiencing significant global warming. So how hot will it get, how soon, and to what effect?
Some climate scientists warn that the pace of global warming could be much more rapid than that predicted even a few years ago.
"Any time you get into projections, you get into a lot of uncertainties. But the [climate] models are getting a lot stronger," said Jay Gulledge, a senior research at the Pew Center on Global Climate Change in Arlington, Virginia.
National Geographic
