Scientists agree global warming is man-made

An overwhelming majority of scientists agree humans have caused global warming, according to a study of scientific literature produced over the past two decades that claims to be the most comprehensive of its kind.

The findings fly in the face of public opinion polls done as recently as last year showing 43 per cent of Americans do not believe scientists agree the earth is getting warmer because of human activity, and 12 per cent do not know.

In fact, the authors of the new study show that of 4,000 peer-reviewed papers by some 10,000 scientists that were published since 1991 and stated a position on the cause of global warming, 97 per cent endorsed the idea that humans had caused it.

The study underlines a “gaping chasm” between the reality of the scientific consensus on climate change and public perceptions, said lead author, John Cook of the University of Queensland.

“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,” he said.

“This is significant because when people understand that scientists agree on global warming, they’re more likely to support policies that take action on it.”

The study found a total of 11,994 papers published on climate change or global warming between 1991 and 2011 by 29,083 authors in 1,980 different scientific journals.

Of these, it found 66.4 per cent stated no position on man-made global warming, often called anthropogenic global warming while 32.6 per cent endorsed it. Only a tiny 0.7 per cent rejected it and the authors of just 0.3 per cent of the papers said the cause of global warming was uncertain.

The peer-reviewed study is published Thursday in the Environmental Research Letters journal, part of the Institute of Physics’ IOP Publishing division.

Its findings are in line with work others have done on the topic recently.

The US scientist, James Lawrence Powell, found 13,950 peer-reviewed scientific articles published between 1991 and 2012 that had the keyword phrases “global warming” or “global climate change”.

By his definition, only 24 of the 13,950 articles, or 0.17 per cent, clearly rejected human-caused global warming, or endorsed a cause other than carbon dioxide emissions for warming.

John Cook and another co-author of the IOP paper, Dana Nuccitelli, were involved in that study.

Separately, another US academic, science historian Naomi Oreskes, did a 2005 study of 928 scientific articles published between 1993 and 2003 that included the phrase “global climate change”. She concluded, after reading the abstracts of each, that “remarkably, none of the papers disagreed with the consensus position” of human-caused global warming.