We should be worried about the impacts of climate change on mental health
By Chia Evers
In his previous work, Nick Obradovich and his collaborators have found broad-scale impacts of temperature on human behaviors and wellbeing, demonstrating that emotional expressions are altered by the weather outside, that sleep is harmed by unusually warm nighttime temperatures, and that hot temperatures reduce physical activity rates (though mild temperatures increase them). They have also uncovered risks that environmental stressors pose to institutions of governance and the electoral process. His most recent paper, showing that climate change poses risks to mental health, highlights an additional, vitally important area of concern, which is likely to interact with each of the above areas.
Obradovich says, “My previous work examining the effects of weather variables on expressions of sentiment online—a measure that we use as a proxy for emotional states—spurred the initial idea for this research. In that paper, we find that extreme temperatures, both hot and cold, worsen people’s expressed sentiments. I wondered, if day-to-day expressed sentiment is altered by the weather, might these effects cumulate into worsened mental health? More recently, a team including one of my previous collaborators found effects of hot temperatures on amplified rates of suicide. So there was evidence that temperature could affect both regular sentiment as well as extreme mental health outcomes. We wondered if it could also affect intermediate mental health quality.”
To answer that question, Obradovich, Iyad Rahwan, and their co-authors set out to examine whether some of the environmental stressors associated with climate change—hotter temperatures, longer-term warming, more severe tropical cyclones—relate to worsened mental health. Using publicly available meteorological data and mental health self report data from the Center for Disease Control’s Behavioral Risk Factor Surveillance Program (BRFSS), they found that hot monthly temperatures increase the probability of experiencing symptoms of poor mental health. They also found associations between longer-run warming and longer-run increases in the prevalence of self-reported mental health issues and discovered that an area’s exposure to Hurricane Katrina was associated with subsequent increases in prevalence of mental health issues. In short, they found empirical evidence that environmental stressors exacerbated by climate change have previously related to worsened mental health in the United States.
When asked why they chose to use self-reported mental health symptoms, Obradovich said, “Many people who suffer from symptoms of mental health disorders do not seek treatment or do not, necessarily, meet criteria for clinical diagnoses, even if they do experience some symptoms and seek treatment. Our measure correlates with outcomes of clinical questionnaires, but one additional advantage it has over medical records is that it likely better captures subclinical and otherwise unreported symptoms in the population. That said, doing these analyses based upon medical records would be a useful next step.”
He also notes, “One of the things we aren’t really able to do in this paper is to examine the long-run effects on mental health that sea-level rise might induce (including forced migration, costs of flood remediation, etc.). Given the magnitude of the likely social effects of sea-level rise, added studies on this topic would be useful to gain a broader sense of what climate change might do to population mental health in the future.”
As Obradovich’s research shows, climate change presents a grave threat to overall human well-being. From daily emotions to mild to moderate mental health problems to extreme consequences like suicide, the environmental factors that climate change is worsening harm our quality of life. And mental health is just one of many social risk areas. Poor mental health quality produces compounding and cumulative social costs; conversely, however, efforts to mitigate the severity of climate change will likely have compounding and cumulative social benefits. Proposed adaptations to the physical effects of climate change must be cognizant of the mental health risks it poses. Improving the quality of mental health care may also increase resilience, especially for those most vulnerable to the impacts of climate change.