Scientists have developed a novel psychological "vaccine" to immunise the public against the damaging "virus" of fake news and misinformation on websites and social media.
In medicine, vaccinating against a virus involves exposing a body to a weakened version of the threat, enough to build a tolerance.
Researchers, including those from University of Cambridge in the UK, believe that a similar logic can be applied to help "inoculate" the public against misinformation, including the damaging influence of 'fake news' websites propagating myths about climate change.
A new study published in the journal Global Challenges compared reactions to a well-known climate change fact with those to a popular misinformation campaign.
When presented consecutively, the false material completely cancelled out the accurate statement in people's minds - opinions ended up back where they started.
Researchers then added a small dose of misinformation to delivery of the climate change fact, by briefly introducing people to distortion tactics used by certain groups.
This "inoculation" helped shift and hold opinions closer to the truth - despite the follow-up exposure to 'fake news'.
The study on US attitudes found the inoculation technique shifted the climate change opinions of Republicans, Independents and Democrats alike.
It is one of the first on 'inoculation theory' to try and replicate a 'real world' scenario of conflicting information on a highly politicised subject, researchers said.
"Misinformation can be sticky, spreading and replicating like a virus," said Sander van der Linden, a social psychologist at Cambridge.
"We wanted to see if we could find a 'vaccine' by pre-emptively exposing people to a small amount of the type of misinformation they might experience. A warning that helps preserve the facts.
"The idea is to provide a cognitive repertoire that helps build up resistance to misinformation, so the next time people come across it they are less susceptible," said van der Linden.
To find the most compelling climate change falsehood currently influencing public opinion, van der Linden and colleagues tested popular statements from corners of the internet on a nationally representative sample of US citizens, with each one rated for familiarity and persuasiveness.
The winner: the assertion that there is no consensus among scientists, apparently supported by the Oregon Global Warming Petition Project.
This website claims to hold a petition signed by "over 31,000 American scientists" stating there is no evidence that human CO2 release will cause climate change.
The study also used the accurate statement that "97 per cent of scientists agree on man-made climate change". Prior work by van der Linden has shown this fact about scientific consensus is an effective 'gateway' for public acceptance of climate change.
In a disguised experiment, researchers tested the opposing statements on over 2,000 participants across the US spectrum of age, education, gender and politics using the online platform Amazon Mechanical Turk.
In order to gauge shifts in opinion, each participant was asked to estimate current levels of scientific agreement on climate change throughout the study.
Those shown only the fact about climate change consensus reported a large increase in perceived scientific agreement -- an average of 20 percentage points.
Those shown only misinformation dropped their belief in a scientific consensus by nine percentage points.
Some participants were shown the accurate pie chart followed by the erroneous Oregon petition. The researchers were surprised to find the two neutralised each other (a tiny difference of 0.5 percentage points).
"It's uncomfortable to think that misinformation is so potent in our society," said van der Linden.
"A lot of people's attitudes towards climate change aren't very firm. They are aware there is a debate going on, but aren't necessarily sure what to believe. Conflicting messages can leave them feeling back at square one," he said.
