Thinking clearly about climate change and mental health

To examine the quality and strength of evidence for an association between temperature increases caused by climate change and suicide used in policy documents to advocate for radical changes to healthcare systems in pursuit of decarbonisation.

The designs of articles collected in a systematic review which concluded that there was an association between climate change and increased rates of suicide were analysed for their capacity to support this conclusion. Complete US data covering temperatures and suicide rates between 1968 and 2004 was aggregated and analysed using linear regression to evaluate evidence for an association between temperature and suicide.

None of the articles collected in the review has a design capable of investigating whether there is an association between temperature increases caused by climate change and rates of suicide. At the national level increased annual US temperatures were associated with a decrease in the rate of suicide, and at the state level it was common for high average temperature states to have low rates of suicide and vice versa.

Policy recommendations for radical changes in healthcare services have been based on misrepresented evidence. Policy makers should beware of recommendations that ignore scientific evidence to pursue faith-based goals.