Tim Tai, Senior Photographer

For decades, scientists have recognized the link between climate disasters and negative mental health consequences. However, a Yale-led study, published in January, revealed that while researchers have extensively studied the mental health effects of short-term disasters, there is little research on how long-term climate change impacts mental health. 

Led by Sarah Lowe, a professor of public health in social behavioral and sciences at the School of Public Health, in collaboration with researchers from the Harvard T.H. Chan School of Public Health, the University of Chicago and Oxford University, the researchers reviewed the scientific literature on the connection between chronic climate change and mental health issues. The study reported that the existing research is sparse — and scientists ought to do much more to help inform specific public health interventions. 

“Climate change is already harming human health, including growing mental health impacts,” Anthony Leiserowitz, the director of the Yale Program on Climate Change Communication, who was not involved in the study, wrote in an email to the News. “This paper underscores the critical need for more research on these impacts and investments in providing mental health support for individuals and communities struggling with the issue of climate change and the aftermath of climate change disasters.”

There is substantial evidence that natural disasters caused by climate change, such as hurricanes — which many scientists consider to be acute climate change — can directly impact mental health.

During a recent Climate Change and Trauma Webinar with the International Society for Traumatic Stress Studies, Betty Lai, a professor in counseling psychology at Boston College who was not involved in the study, highlighted this connection. 

“Disasters are directly linked to potential mental health distress symptoms,” Lai said.

Lai said that climate disasters especially affect children, recalling one study that demonstrated that one in four children who witnessed Hurricane Ike in 2008 were still reporting anxiety and PTSD symptoms 15 months later. 

In the webinar, Lowe noted that much of her research typically centers on the long-term mental health consequences of traumatic events. Her doctorate began with a study on how Hurricane Katrina exacerbated socioeconomic and racial disparities. 

However, after joining the School of Public Health in 2019, Lowe said, she realized that the bulk of research on climate change and mental health focuses only on acute climate change and not on the effects of long-term climate change. 

“[I]t seemed obvious that climate change could influence mental health in other ways, and I was hearing a lot from young people and in the media about how the threat of climate change escalation was leading to significant anxiety,” Lowe wrote in an email to the News. “We decided to embark on this systematic review to see what work had been done on the topic, knowing that there was likely to be research outside of our specialties.”

In the study, the researchers analyzed qualitative, quantitative and mixed-methods studies that examined the effects of slow-onset climate change on mental health indicators, which, according to Lowe, ended up being a “huge undertaking.” After screening over 10,000 abstracts, they included only 57 in the final review. 

They found that there is a lack of research on the specific link between chronic climate change and PTSD and post-traumatic stress symptoms. Most studies, they claimed, tended to focus on how the climate affects anxiety and depression symptoms and negative emotions, such as sadness, fear and anger. In addition, they noted that low and middle-income countries, the places most likely to feel the effects of chronic climate change, have less research output.

Lowe said she was especially surprised by how small the body of literature is on chronic climate change and mental health.

“As a point of comparison, I conducted a review of studies published in 2018 on PTSD and depression symptoms after disasters; in that single year, without using gold-standard systematic review methodologies, and focusing on only two outcomes, my colleagues and I identified 100 peer-reviewed articles on the topic,” Lowe wrote. 

For Lowe, because this body of research is so small, it is too early to determine the main differences between chronic climate change and acute climate change. Still, the preliminary evidence suggests that acute natural disasters may have more consistent negative impacts and are more likely to cause PTSD-related symptoms. 

Lowe emphasized the importance of conducting more qualitative and quantitative research across different disciplines to clarify the effects of chronic climate change. She also noted that longitudinal cohort studies, combined with interviews and focus groups, could help researchers learn more clearly how climate change affects overall well-being. 

Joan Monin, a professor of public health at the School of Public Health, who was not involved with the study, praised the call for more climate change research, noting how it could impact future policy. 

“This work is so important because it suggests that policymakers can implement changes to mitigate the effects of climate change,” Monin wrote in an email to the News. “This can have far-reaching effects on the mental health of large communities.”

According to the National Institute of Mental Health, it is estimated that one in five adults in the United States live with a mental illness.