How Climate Change Impacts Mental Health

According to the White House, climate disasters such as floods, hurricanes, tornadoes, and others cost approximately $145 billion last year and affected one-third of Americans in the summer of 2021. The pattern of worsening extreme weather events shows no signs of calming down. For example, an April 2022 report from Colorado State University predicted 19 named storms during the upcoming Atlantic hurricane season beginning June 1, 2022, with 71 percent expected to impact U.S. coastline areas.

These projections foreshadow an increase in mental illness. In a sample of 316 survivors of Hurricane Harvey’s 2017 impact in Houston, Texas, 40 percent endured post-traumatic symptoms, and 25 percent met the formal criteria for post-traumatic stress disorder. The threat is not limited to coastal regions, however. A survey of mental health sequelae in Tennessee following a nocturnal tornado outbreak in March 2020 revealed higher rates of depression and post-traumatic stress among survivors who directly experienced tornado-related damage (e.g., physical injury, property damage). Black and Latinx populations who experienced barriers and delays in advanced warnings from public authorities demonstrated a disproportionately greater risk of mental illness.

The impacts of climate change go beyond extreme weather events.

Ecological changes in air quality induced by greenhouse gas emissions also illustrate how one’s environment and emotional well-being are inextricably linked. Air pollutants have direct consequences on both physical and mental health. According to a February 2022 study, exposure to air pollutants is associated with increased severity of psychiatric symptoms among male veterans. Children exposed to environments with long-standing air pollution are especially at risk for abnormal developmental trajectories.

Anthropogenic global warming (e.g., rising temperatures due to human activity) is now firmly established as a contributor to the decline in mental health, including increased frequency of mental health hospitalizations, suicide attempts, and interpersonal violence, such as sexual offenses and intentional homicides. The effects are again disproportionate, with the strongest associations between urban crime violence and extreme heat seen in high-poverty neighborhoods and amounting to nearly five times the monetary cost compared to more affluent areas.

A 2022 study published in the Journal of the American Medical Association showed an 8 percent increase in mental health visits to emergency departments during periods of extreme heat, with corresponding rises in emergency room utilization for substance use disorders (8 percent), anxiety (8 percent), mood disorders (7 percent), and acts of self-harm (6 percent). These associations were especially pronounced for areas of the Northeast, Northwest, and Midwest.

Interventions that address climate change have the potential to decrease associated mental duress.

As a field, psychiatry must acknowledge that extreme weather events and climate-related disasters can leave an indelible mark on child development and are best classified as adverse childhood experiences. Such recognition will catalyze research on the effects of climate change on human development. Teaching medical professionals about the effects of climate change on physical and mental health is overdue and will enhance the care clinicians provide.

Of course, mental illness has no singular cause, and climate change is not solely responsible. The etiology of mental illness is often multifactorial, with genetic, epigenetic, and sociocultural influences. But neglecting the mounting evidence that climate-related events set the stage for personal trauma is myopic, and assuming that the increased need for mental health services can be absorbed with more psychiatrists or behavioral health providers in the future is foolhardy in our presently overburdened system of care.

Climate change and its distal impacts—flooding, wildfires, warming, and others—pose a significant risk to both the planet but also the emotional well-being of those who inhabit it. It is time that the mental health repercussions be acknowledged not as an afterthought but as a primary driver of policy change and climate action.