Associated Press: Scientists are more confident than ever that pumping carbon dioxide into the air by burning fossil fuels is warming the planet. The question is, by how much?
It's something that officials and scientists meeting in Stockholm will try to pin down as precisely possible Friday in a seminal report on global warming.
Future global warming levels depend on two major factors. One is how much more carbon dioxide (CO2) and other greenhouse gases are pumped into the air and how quickly.
The other is...