Study: Scientific consensus on man made climate change

A study of 11,994 scientific papers published between 1991 and 2011 is the most comprehensive yet in showing overall scientific consensus on whether climate change is anthropogenic, or man-made.

Public opinion on global warming consistently shows that more than half of Americans believe there is debate among scientists as to whether climate change is caused or exacerbated by human activities.

Science Codex reports that study leader John Cook of the University of Queensland said the study's findings "prove that there is a strong scientific agreement about the cause of climate change, despite public perceptions to the contrary."

After limiting the selection to peer-reviewed climate science, the study considered 11,994 papers written by 29,083 authors in 1,980 different scientific journals. Each abstract was analyzed by two independent, anonymous analysts who used set criteria to rate the level to which a paper endorsed anthropogenic global warming (AGW) or not.

Researchers identified 4,000 abstracts that stated a clear position on the cause of global warming. Among these, there was 97 percent consensus that global warming is man made. Researches then asked the authors of more than 2,000 of these studies to rate their entire papers using the same criteria, and they reached a 97 percent consensus for AGW.

Of the 11,994 studies analyzed, 66.4 percent stated no clear position in the abstract of the paper. AGW was endorsed in 32.6 percent of studies, 0.7 percent rejected AGW outright, and 0.3 percent of papers stated the cause was uncertain.

"There is a gaping chasm between the actual consensus and the public perception," Cook said. "It's staggering given the evidence for consensus that less than half of the general public think scientists agree that humans are causing global warming."

The study was published Thursday in Environmental Research Letters.