Climate change is contributing directly to increased injuries, illnesses, and deaths from climate-sensitive health outcomes, with health risks projected to increase as temperatures, precipitation, and other variables continue to change. There is growing evidence that changing climatic conditions are adversely affecting mental health, including increased risk of stress, clinical disorders (trauma, anxiety, PTSD, or depression), and can even result in increased risk of suicide. Mental health impacts can last for years after an extreme event, and be transmitted to later generations.

Mental disorders and substance-use disorders account for 5–10% of national disease burdens, with women nearly twice as likely as men to suffer from mental illness. Mental and addictive disorders affect more than 1 billion people globally. Growing public awareness of the current impacts and future risks of changing climate and weather patterns could undermine mental health also for those not directly affected by climate-related disaster, especially among youth concerned about the future. Indirect mental health impacts include eco-anxiety, ecological grief, biospheric concern, and solastalgia (distress caused by the experience of environmental change).

Cascading and compounding risks across spatial and temporal scales are amplifying the impacts of these events and adversely affecting mental health. Wildfires, rising sea levels, coastal erosion, deforestation, and thawing permafrost will contribute to relocation, displacement, and migration away from vulnerable sites. Population displacement heightens psychosocial risks as community networks, livelihoods, and place attachment are disrupted.

There is growing governmental acknowledgment of the magnitude of the burden of mental health impacts. In Pacific Island countries, climate-sensitive health risks of high priority include trauma from extreme weather events and psychosocial impacts linked to emerging and anticipated climate change impacts. For example, a study of climate change and distress in the country of Tuvalu found that climate change and the threat it portends for the future is a determinant of distress among residents of Funafuti atoll. In Canada, the 2013 Southern Alberta flood resulted in long-term mental health impacts.

Health systems need to proactively plan to include mental health support for people affected by climaterelated disasters. This can be achieved by implementing international agreements around mental health support for affected populations, people on the move, as well as those “left behind.” Further, climate mental health specialists can be trained to provide trauma-informed care for mental distress. One example is supporting those staying in temporary shelters for prolonged periods of time – if shelters are even available – when living spaces are damaged or destroyed.

Further research is required to advance understanding of the causal associations and attributions between climate change – including disasters – and mental health consequences, and what the most effective solutions are. Social and environmental justice concerns need to be addressed as well: to improve communication and outreach; increase mental health literacy; and develop culturally relevant resources. Mental health and well-being and emotional resiliency can be improved when there is an extreme event or disaster, especially by focusing interventions on disproportionately affected groups.