Climate change scientists: why and when we believe them
Whatever their political persuasion, people are more likely to believe that global warming is caused by humans if they find out that most climate change scientists believe this is the case.
Professor Stephan Lewandowsky, of The University of Western Australia's School of Psychology, was the team leader of a study to determine whether people's belief in anthropogenic global warming (AGW), was different if they thought there was consensus on the issue among climate change scientists.
For the study, "The Pivotal Role of Perceived Scientific Consensus in Acceptance of Science", published in Nature Climate Change earlier this month, the researchers recruited members of the public to find out if the way they thought about scientific issues was consistent with their personal ideology or worldview.
Half the participants were randomly assigned to one of two groups: a control group in which no consensus information was provided; and a second group in which participants were told that 97 per cent of climate change scientists agreed that AGW was happening.
When asked afterwards to express their opinions about AGW, and to attribute recent trends in temperature or sea level to human CO2 emissions, people who had received the consensus information were more likely to accept the scientific evidence than the control group.
"Clearly, the presentation of the consensus amongst climate scientists has a powerful effect on people's beliefs," Professor Lewandowsky said.
Participants were also asked to respond to a series of statements to assess their worldview, for example their opinion of the free market, and the researchers found (as in previous studies) that those who endorsed a fundamentalist view of the free market leaned towards a rejection of AGW. However, in this investigation, the researchers found that highlighting the consensus amongst climate scientists could be a powerful interacting factor.
"For me, the most interesting aspect of the study was that the strong correlation between belief in free-market ideology and lack of belief in AGW was attenuated for people who were told that 97 per cent of climate scientists agree that the global atmosphere is warning, and it is very likely to due to the burning of fossil fuels," Professor Lewandowsky said.
"This is important, because it highlights the potentially crucial role that underscoring the scientific consensus can play on beliefs in members of the general public, irrespective of their political persuasion."