Suzanne Goldenberg guardian.co.uk 16 May 13;
A survey of thousands of peer-reviewed papers in scientific journals has found 97.1% agreed that climate change is caused by human activity.
Authors of the survey, published on Thursday in the journal Environmental Research Letters, said the finding of near unanimity provided a powerful rebuttal to climate contrarians who insist the science of climate change remains unsettled.
The survey considered the work of some 29,000 scientists published in 11,994 academic papers. Of the 4,000-plus papers that took a position on the causes of climate change only 0.7% or 83 of those thousands of academic articles, disputed the scientific consensus that climate change is the result of human activity, with the view of the remaining 2.2% unclear.
The study described the dissent as a "vanishingly small proportion" of published research.
"Our findings prove that there is a strong scientific agreement about the cause of climate change, despite public perceptions to the contrary," said John Cook of the University of Queensland, who led the survey.
Public opinion continues to lag behind the science. Though a majority of Americans accept the climate is changing, just 42% believed human activity was the main driver, in a poll conducted by the Pew Research Centre last October.
"There is a gaping chasm between the actual consensus and the public perception," Cook said in a statement.
The study blamed strenuous lobbying efforts by industry to undermine the science behind climate change for the gap in perception. The resulting confusion has blocked efforts to act on climate change.
The survey was the most ambitious effort to date to demonstrate the broad agreement on the causes of climate change, covering 20 years of academic publications from 1991-2011.
In 2004, Naomi Oreskes, an historian at the University of California, San Diego,surveyed published literature, releasing her results in the journal Science. She too came up with a similar finding that 97% of climate scientists agreed on the causes of climate change.
She wrote of the new survey in an email: "It is a nice, independent confirmation, using a somewhat different methodology than I used, that comes to the same result. It also refutes the claim, sometimes made by contrarians, that the consensus has broken down, much less 'shattered'."
The Cook survey was broader in its scope, deploying volunteers from the SkepticalScience.com website to review scientific abstracts. The volunteers also asked authors to rate their own views on the causes of climate change, in another departure from Oreskes's methods.
The authors said the findings could help close the gap between scientific opinion and the public on the causes of climate change, or anthropogenic global warming, and so create favourable conditions for political action on climate.
"The public perception of a scientific consensus on AGW [anthropogenic, ie man-made, global warming] is a necessary element in public support for climate policy," the study said.
However, Prof Robert Brulle, a sociologist at Drexel University who studies the forces underlying attitudes towards climate change, disputed the idea that educating the public about the broad scientific agreement on the causes of climate change would have an effect on public opinion - or on the political conditions for climate action.
He said he was doubtful that convincing the public of a scientific consensus on climate change would help advance the prospects for political action. Having elite leaders call for climate action would be far more powerful, he said.
"I don't think people really want to come around to grips with the fact that climate change is a highly ideological issue and it is not amenable to the information deficit model," he said.
"The information deficit model, this idea that if you just pile on more information people will get convinced, is just completely inadequate, he said. "It strengthens the people who actually read and pay attention but it is certainly not going to change or shift the opinions of others."
Scientists say united on global warming, at odds with public view
Alister Doyle PlanetArk 16 May 13;
Ninety-seven percent of scientists say global warming is mainly man-made but a wide public belief that experts are divided is making it harder to gain support for policies to curb climate change, an international study showed on Thursday.
The report found an overwhelming view among scientists that human activity, led by the use of fossil fuels, was the main cause of rising temperatures in recent decades.
"There is a strong scientific agreement about the cause of climate change, despite public perceptions to the contrary," said John Cook of the University of Queensland in Australia, who led the study in the journal Environmental Research Letters.
"There is a gaping chasm between the actual consensus and the public perception," he said in a statement. "When people understand that scientists agree on global warming, they're more likely to support policies that take action on it."
Global average surface temperatures have risen by 0.8 degree Celsius (1.4F) since the Industrial Revolution.
Experts in Australia, the United States, Britain and Canada studied 4,000 summaries of peer-reviewed papers in journals giving a view about climate change since the early 1990s and found that 97 percent said it was mainly caused by humans.
They also asked authors for their views and found a 97 percent conviction from replies covering 2,000 papers. The data will be released at (www.skepticalscience.com).
The report said it was the biggest review so far of scientific opinion on climate change.
"If people disagree with what we've found we want to know," said Mark Richardson of the University of Reading in England, one of the authors of the study that looked at English-language studies by authors in more than 90 nations.
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.
A survey by the U.S. Pew Research Center published in October last year found 45 percent of Americans said "Yes" when asked: "Do scientists agree Earth is getting warmer because of human activity?" Forty-three percent said "No".
Rising concentrations of carbon dioxide, the main greenhouse gas, hit 400 parts per million in the atmosphere last week, the highest in perhaps 3 million years.
Governments have agreed to work out, by the end of 2015, a deal to slow climate change that a U.N. panel of experts says will cause more floods, droughts and rising sea levels.
(Reporting By Alister Doyle; Editing by Janet Lawrence)
