A survey of the abstracts of almost 12,000 scientific papers from 1991-2011 shows the great majority of scientists who stated a position on the evidence endorsed the view that humans are to blame. Just 1.9 per cent rejected the view.
The University of Queensland-led study claims to be the largest peer-reviewed study of its kind.
It is published in the journal Environmental Research Letters, based on the work of 24 scientists and others recruited through skepticalscience.com. Ratings were cross-checked and authors were contacted to rate their own papers.
The study looked at English-language studies by authors in more than 90 nations.
An account of the findings has been reported at Stuff (here).
The report’s lead author, John Cook, a fellow at the University of Queensland’s Global Change Institute and founder of the website skepticalscience.com, said the scientific consensus was overwhelming, growing and had been around since the early 1990s.
He said that while the number of papers rejecting the consensus was “vanishingly small”, his research suggested the public was under the impression the debate was split 50-50.
“When people think scientists agree, they are more likely to support a carbon tax or general climate action,” he said.
“But if they think scientists are still arguing about it, they don’t want to do anything about it.”
Stuff reports that carbon dioxide levels in the atmosphere are about 400 parts per million and rising – the highest in more than 3 million years.
The fifth assessment report of the Intergovernmental Panel on Climate Change is due to update its findings on research into global warming and the potential impact on societies and the environment from this September.
Cook said scientists now found less need to state their position on climate change in abstracts summarising their papers, “just as geographers find no reason to remind readers that the earth is round”.
He said the level of endorsement – 97.2 per cent of the one-fifth who replied – was in line with the overall findings.
He likened the strength of the scientific consensus to the theory of plate tectonics, or continental drift, that took 50 years to gain acceptance.
In that case, he said the media found little reason to stoke controversy because there was “no political or ideological issue with plate tectonics”, he said.
Mark Richardson, from the University of Reading in England, said if people disagreed with what the team has found, “we want to know”.
Another co-author, Dana Nuccitelli of Skeptical Science, said she was encouraging scientists to stress the consensus “at every opportunity, particularly in media interviews”. Opinion polls in some countries show widespread belief that scientists disagree about whether climate change is caused by human activities or is part of natural swings such as in the sun’s output.