They are either championed as brave voices willing to speak out against the scientific majority or dismissed as cranks who lack the evidence to support their arguments.
Now deniers of global warming have been dealt a stinging blow by psychologists who found skeptics of man-made climate change tend to believe in conspiracy theories.
They say the conspiracist outlook taken by many climate change skeptics is harming the public debate over global warming.
They found around a fifth of the comments about the research ‘can be considered conspiracist’.
It builds on a previous survey that the researchers conducted, which found up to 40 per cent of those who are skeptical about global warming use imagery that invoked conspiracy theories.
This includes the use of words like ‘scam’ and repeated references to faked data and collusion between scientists and governments to deliberately conceal evidence.
Professor Stephan Lewandowsky, an experimental psychologist at the University of Bristol who led the work, said: ‘These results add to a growing body of research on the nature of internet discourse and the role of the blogosphere in climate denial.
‘It also confirms that conspiratorial elements are readily identifiable in blogosphere discourse’
The paper, which is published in the Journal of Social and Political Psychology, provides a damning view of skeptical bloggers and those who comment on their websites.
The term ‘conspiracy theory’ is often used as a way of dismissing and ridiculing a person’s beliefs.
Well known conspiracies include claims that the existence of alien life has been covered up and that the Moon landings were faked.
The majority of scientists deny there is a conspiracy to paint climate change as worse than it is and Prince Charles, who campaigns on environmental issues, recently insisted there was no such conspiracy.
He said the international bodies that now accept the threat of climate change could ‘scarcely be accused of being part of some half-baked conspiracy dreamt up by extreme environmentalists intent on undermining capitalism’.