In the US, studies have repeatedly shown a link between political conservatism and climate denial, but a new study has revealed that this relationship may not exist in most other countries.

Many of the prior studies that have found a link between conspiratorial or conservative ideologies and the rejection of anthropogenic climate change have been based in the US.

The lack of international research on the topic was what ultimately piqued the interest of some Australian scientists.

Researchers from the University of Queensland set out to fill in the gaps in our knowledge – in large part because of the 2016 US elections.

"I was intrigued why, of the 17 candidates who campaigned to be the Republican nominee for the 2016 United States presidential campaign, many were openly skeptical of climate science," said co-author Professor Matthew Hornsey from UQ's School of Psychology and School of Communication and Arts.

"This mainstream rejection of climate science among a major political party was not evident in other countries, which raised the question: is the tendency for conservatives to be more climate sceptical a global phenomenon, or something that's distinctively American?"

Examining the link between political conservatism and climate denial on an international scale, the UQ researchers surveyed over 5,000 people across 25 countries.

The study found that in around three quarters of the countries surveyed, conservatives didn't show any more denial of climate change than their political counterparts.

Interestingly enough, in countries with low levels of carbon emissions no link was found between conservatism and climate denial. On the other hand, in countries with high levels of carbon emissions, including Australia and America, there was a stronger link.

"One possible reason is that conservatives in countries with high carbon emissions have more of a vested interest in rejecting climate science, due to the fossil fuel industry's investment in that country," explained Hornsey.

While the results suggest that this link is not "uniquely" American, it has revealed that America is one of the few countries in the world where this is the case.

If Hornsey's theory is correct, it would be more accurate to say that the link between conservatism and climate denial appears unique to countries with powerful fossil fuel industries.

The UQ researchers also examined how conspiratorial ideologies fit in with climate denial – after all, it would have to be a pretty big conspiracy for 97 percent of all actively publishing climate scientists to spread such a hoax.

In the study, participants were asked about their opinions on four of the most notorious conspiracies: that Princess Diana was murdered, that JFK was killed in an organized plot, that the US government knew about 9/11 before it was going to happen, that there is a group of elites conspiring to create a New World Order.

Unsurprisingly, President Trump was the influence for this part of the study.

"The inspiration for this question was Donald Trump's tweet saying that climate science was a hoax created by the Chinese to make US manufacturing uncompetitive," Professor Hornsey said.

The findings suggest that the more Americans think climate change is a hoax, the more likely they are to believe in other conspiracies.

Big deal, right? That makes sense.

But here's the real mystery: that relationship wasn't found in the vast majority of other countries.

Hornsey said the climate change views of non-American participants were not strongly linked with conspiratorial thinking, or their politics.

"This suggests that ideological barriers to accepting science don't emerge from people spontaneously critiquing scientific consensus through the lens of their world views," said Hornsey.

"Rather, ideological barriers to accepting science can also be encouraged by influential individuals and organisations who have a vested interest in communicating that the science is wrong."

The new study will have important implications for international strategies that are seeking to combat climate denial. It also reveals the powerful influence that the fossil fuel industry can have on local politics, opinions and beliefs.

The study has been published in Nature Climate Change.

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