Scientific consensus shifts public opinion on climate change

Although most experts agree that CO2 emissions are causing anthropogenic global warming, public concern has been declining, the study said. http://www.flickr.com/photos/kimjphotography

People are more likely to believe that humans cause global warming if they are told that 97% of publishing climate scientists agree that it does, a new study has found.

Despite overwhelming evidence showing that human activity is causing the planet to overheat, public concern is on the wane, said the study, titled The pivotal role of perceived scientific consensus in acceptance of science and published in the journal Nature Climate Change on Monday.

“One reason for this decline is the ‘manufacture of doubt’ by political and vested interests, which often challenge the existence of the scientific consensus. The role of perceived consensus in shaping public opinion is therefore of considerable interest,” the study’s authors said.

Overall, participants in the study greatly underestimated the level of scientific agreement on the issue, the study said.

Lead researcher Stephan Lewandowsky from the Cognitive Science Laboratories at the University of Western Australia said the study involved two surveys.

In the first, 200 Perth pedestrians were asked about their views on the scientific research linking human CO2 emissions to climate change as well as their thoughts on medical research linking smoking to lung cancer and HIV to AIDS.

The results showed that people who had faith in scientific or medical research in general were more likely to accept expert opinion on climate change.

“So some people just accept science as an endeavour and it doesn’t matter whether is the science is about climate or something else,” said Prof Lewandowsky.

The second study involved surveying 100 Perth pedestrians – half in a control group and half in a ‘consensus group’.

The control group was asked about their views on the causes of climate change but the consensus group, however, was first told that 97% of publishing climate scientists agree that global warming is a direct consequence of the burning of fossil fuels by humans.

People in the consensus group were much more likely to say that human activity caused climate change, even if their political views were otherwise broadly in line with free market ideologies that eschew the government regulation required to curb emissions.

“So providing the consensus information is boosting acceptance, particularly for those people who would otherwise reject the evidence based on their world view,” said Prof Lewandowsky.

“Telling them about this numeric fact about agreement in the scientific community does make a difference. That’s quite remarkable because few things work.”

Other studies have shown that presenting evidence alone does little to change minds and can even lead to people becoming more entrenched in their disbelief of human-caused climate change, he said.

The study showed it was important for scientific communicators and journalists to tell their audience that the vast majority of climate change experts believe that human activity is causing global warming.

“It is reaching even those people who would normally tune out when you tell them the evidence,” Prof Lewandowsky said, adding that journalists should not give denialists and climate change experts equal air time.

“The media is being irresponsible if they are pretending there is a scientific debate in light of this consensus.”

Will J Grant from the Australian National Centre for the Public Awareness of Science at the Australian National University said it was an interesting and useful study.

“We can say people are convinced by the consensus but the big caveat is sceptics and climate change sceptics in particular are never going to be convinced by this,” he said. “They will say science doesn’t work by vote, it’s about facts.”

“Realistically, though, most of those sceptics are of an older generation. We are never going to convince them but they will be disappearing from the political discourse soon.”