Background
Climate, the Earth’s ecosystems, biodiversity, and human civilization are all closely connected. Climate change is man-made, and the consequence of it surpasses the capacity of various ecosystems to adapt. The loss and damage caused are becoming an increasingly palpable and visible threat to human health. Although it may not be possible to specify a clear causal relationship, climate change has however led to an increase in the frequency and intensity of natural disasters and extreme weather events. This overall condition is also associated with long-term changes to living conditions which can have a stressful impact on mental well-being.
Objective
To summarize the current global evidence regarding the effects of climate change on mental health.
Methods
- Using the literature databases PubMed and PsycINFO, a systematic search was performed for the direct effects (natural disasters, i.e., floods, fires, storms, heat, and drought) and indirect effects (food insecurity, climate-related migration) of climate change on mental health.
- The search included studies involving all human populations, worldwide.
- 1017 studies were identified and 128 were included.
Results
- The available evidence indicates that traumatic experiences due to extreme weather events increase the risk of affective and anxiety disorders, especially the risk of post-traumatic stress disorder.
- Heat significantly increases the morbidity and mortality attributable to mental illness, as well as the frequency of psychiatric emergencies.
- People affected by drought have a 26% higher likelihood of mental problems than those not affected.
- Storms and tornadoes cause damage, destruction, and mental stress to patients with pre-existing mental disorders.
- Persistent stressors like food insecurity and migration owing to climate change can also be major risk factors for mental illness.
Conclusion
The results of this review suggest that the consequences of climate change are stress factors for mental health. Thus, as global warming progresses, increasing evidence and prevalence of mental illness are to be expected. Vulnerable groups like the mentally ill, children, and adolescents need to be protected. The slowing down of climate change by decreasing CO2 emissions and measures to also counteract the long-term effects of climate change (for example, green areas in towns, heat protection in hospitals) are urgently needed.