Climate Change: Scientists Witness Greenhouse Effect in Action

The climate-changing greenhouse effect exists and has been directly measured in the United States, a new study reports.

The results confirm what scientists had already proved through models and laboratory experiments: Pumping carbon dioxide gas into the atmosphere is warming the Earth's surface.

"We're actually measuring the fact that rising carbon dioxide concentrations are leading to the greenhouse effect," said lead study author Dan Feldman, a scientist at the Lawrence Berkeley National Laboratory in California. "This is clear observational evidence that when we add carbon dioxide to the atmosphere, it will push the system to a warmer place."