Climate change and related mental health problems will have a larger impact on marginalized groups, fragile health systems and poorer countries.³⁵ As a result, social and health inequities will worsen across the globe; for example, people who are most affected by the physical and mental health toll of climate change, particularly those in poorer countries, are the people least responsible for it.³⁶  

Climate change may also lead to an increase in the global economic cost of mental health problems. Mental illness already costs $2.5 trillion globally. As the number of people with mental illness increases due to climate change, the related costs will also increase. For example, mental health supports and resources provided after the Australian bushfires in 2020 cost $76 million.³⁷  

Climate change and related mental health problems may also affect health care systems and services. Mental health care systems are already overburdened, and failing to plan for an increase in the number of people who need services will leave many people without access to care. This will have the greatest impact in rural areas and poorer countries with fewer mental health resources and where populations are most at risk of climate change–related mental health problems.³⁸ Sudden and severe climate change hazards (e.g., extreme weather) can also damage health care infrastructure and interrupt supply chains, affecting the ability to provide services.³⁹