Chris Field, a member of the Nobel Prize-winning Intergovernmental Panel on Climate Change, says decisive action is needed to prevent the planet's climate system from crossing a critical threshold by the end of the century.
Field, director of the Carnegie Institution's Department of Global Ecology, said studies indicate greenhouse warming could trigger a vicious cycle in which carbon dioxide released from thawing tundra and increasingly fire-prone forests drives global temperatures even higher.
"The data now show that greenhouse gas emissions are accelerating much faster than we thought," said Field, with new studies also revealing potentially dangerous feedbacks in the climate system that could convert current carbon sinks into carbon sources.
"One thing that seems to be certain, however, is that as a society we are facing a climate crisis that is larger and harder to deal with than any of us thought," Field said. "The sooner we take decisive action, the better our chances are of leaving a sustainable world to future generations."
The research was presented this week in Chicago during the annual meeting of the American Association for the Advancement of Science.