Moderate skeptics on the other hand were highly likely to change their beliefs once given more evidence of recorded temperature change.
A secondary goal of the paper was to bridge competing theories of climate skepticism as a social phenomenon by looking closely at "source credibility" from the skeptic's perspective. In other words, McDermottt said, there is a need to acknowledge that many skeptics regard mainstream sources of climate science as untrustworthy. They may not trust scientists over their own sources, which in turn could help to explain why they don't update their beliefs as scientists provide more information.
"One implication of that is that if you're trying to think about who to target with messaging to persuade people that climate change is a real and observable phenomenon, you should just accept that some people you're just not going to convince, even with more years' worth of evidence."
Because McDermott employed a quantitative model, he calls the project "a grandiose thought experiment" that uses "hypothetical, stylized skeptics." While some climate scientists have employed complicated supercomputer models, McDermott's Bayesian mathematical model uses simpler, standard econometric techniques - bread and butter to environmental economists like him. At its essence, the model provides a framework for combining prior beliefs with new information and seeing how beliefs are updated.
McDermott suggests that further research could be directed to disentangle the root causes of strongly-held skeptic beliefs. Specifically, are skeptics extremely sure of their priors, or simply mistrustful of scientific sources about climate change? Or, perhaps it is some combination of the two?
"The actions of others may often seem irrational to us, and vice versa, but it's important to recognize that a person's actions are, more than likely, perfectly congruent with their internal belief system," McDermott said. "Acknowledging that is an important first step towards crafting effective public policy."