Are climate sceptics more likely to be conspiracy theorists?

It's time to come clean: climate change is a hoax. And the moon landings were faked, 9/11 was an inside job, and the CIA is hiding the identity of the gunman on the grassy knoll.

It might seem odd to lump climate change – a scientific theory supported by thousands of peer-reviewed papers and hundreds of independent lines of evidence – with conspiracy theories like these. But new research to be published in a forthcoming issue of Psychological Science has found a link between the endorsement of conspiracy theories and the rejection of established facts about climate science.

In a survey of more than 1,000 readers of websites related to climate change, people who agreed with free market economic principles and endorsed conspiracy theories were more likely to dispute that human-caused climate change was a reality.

Stephen Lewandowsky and his colleagues at the University of Western Australia posted a link to an online questionnaire on eight climate-related blogs with a diverse readership, in order to capture people's views about economics, science and conspiracy theories. Five "sceptic" (or "sceptic-leaning") blogs were also approached but declined to post the link – interesting in and of itself, given the frequent claim that sceptical views are excluded from mainstream debates.

What they found was remarkable. People who endorsed conspiracy theories such as "9/11 was an inside job" and "the moon landings were faked", were also more likely to reject established scientific facts about climate change, such as "I believe that the burning of fossil fuels on the scale observed over the last 50 years has increased atmospheric temperatures to an appreciable degree."

Clearly, a self-selecting sample of blog users is not representative of the wider population. But this is precisely why the researchers targeted this group: in the cut-throat world of climate change scepticism, this is undoubtedly where the action is.

Lewandowsky's research poses difficult questions for the climate sceptic community. Although they are not a homogenous group, they tend to coalesce around common themes relating to the reality and seriousness of climate change. The findings suggest that at least some proportion of the people who consider themselves sceptical about climate change are also willing to entertain conspiracy theories that are not taken seriously in mainstream society.

All scientists are sceptics: it is a healthy, everyday part of the process of systematically weighing up evidence and reaching a considered conclusion. But if vocal online opponents of climate change science also do not accept basic historical truths about society, can their position really be described as "scepticism"?

The findings provide yet more evidence that a rejection of climate science has more to with ideological views than scientific literacy, bolstering the well-supported finding that climate change scepticism is more likely to be found on the right, than on the left of politics. But they go a step further, adding an important layer of detail to the crude characterisation of climate change scepticism as a "conservative" issue.

The link between endorsing conspiracy theories and rejecting climate science facts suggests that it is the libertarian instinct to stick two fingers up at the mainstream – whatever the issue – that is important. Because a radical libertarian streak is the hallmark of free-market economics, and because free market views are popular on the political right, this is where climate change scepticism is most likely to be found.

The findings also suggest that talk of a 'consensus' on climate change is a double-edged sword: on the one hand, the weight of scientific evidence showing that humans are changing the climate is a powerful argument for taking action to prevent its dangerous effects. But the very notion of consensual agreement is also a red flag to libertarians, who distrust statements about consensus on principle.

All of this suggests that the battle to overcome climate scepticism – if that is even a useful way of thinking about it – will not be won by simply restating the scientific facts. The problem is that "the facts" are not "the facts" for a small proportion of people – and the noise made by this minority group dilutes the otherwise clear signal about climate change received by the wider population.

Climate change is a scientific entity, but one given meaning through the social, political and economic lenses we view it through. The challenge of engaging with climate change sceptics is finding the lens that better fits their ideological views – not just shouting the science more loudly.