The negative impact of climate change on our mental health

Global warming’s impact ranges from PTSD after extreme weather to general ‘ecoanxiety’

While on holiday in Western Canada last month I had what you might call my first personal brush with climate change.

A day after we left accommodation on the coast of British Columbia, the village we had stayed in was placed under evacuation alert. A wildfire had started just above it, leading to the evacuation warning and the closure of the only road serving that portion of the coast. The area had been remarkably dry and dusty, to the obvious concern of locals.

Further confirmation of global warning has been the inexorable increase in wildfires across the province in recent years. And while we hadn’t actually been there for the fire, it was unsettling, and a reminder that the planet, which is warming due to human activity, is progressively becoming less livable.

What does medical research tell us about mental-health issues arising from the ongoing wave of bad climate-change news?


Poor air quality increases asthma and allergy attacks and can cause other respiratory problems leading to hospitalization

The World Health Organisation has predicted some 250,000 deaths per year between 2030 and 2050 due to climate change. And the UN has predicted that the average 4 degree Celsius rise in temperature by the end of the century means sea levels would rise enough to drown coastal cities, and crop yields would decline precipitously.

PTSD and ecoanxiety

Direct traumatic experiences such as losing a home to a hurricane have mental-health consequences. After Hurricane Katrina hit the US Gulf Coast in 2005, suicide and suicidal ideation among residents of areas affected by the disaster more than doubled, while one in six met the criteria for post traumatic stress disorder (PTSD). Rates of depression also doubled in New Orleans, with a disproportionate impact on the mental health of those with the lowest incomes. Elevated PTSD levels have also been found among people who live through wildfires and severe storms.

Less acute exposure can have still some effect. In 2017, the American Psychological Association validated "ecoanxiety" as a legitimate affliction. "Some of the most resounding chronic psychological consequences" of climate change will stem from slower-moving disasters, like the "unrelenting day-by-day despair" of a prolonged drought, the APA said. "Gradual, long-term changes in climate can also surface a number of different emotions, including fear, anger, feelings of powerlessness, or exhaustion."

Spread of bacteria

There is no denying that global warming causes increases in heat waves, humidity, and air pollution, and increases rainfall – leading to flooding and mudslides. Extreme heat can cause heat-related illness and death from heat stroke and dehydration. Poor air quality increases asthma and allergy attacks and can cause other respiratory problems leading to hospitalization. A rise in temperature can also extend the geographic range of disease-carrying mosquitos and ticks, resulting in faster and wider spread of a variety of diseases.

Rising temperatures and extreme weather conditions make it easier for food and water to become contaminated by bacteria, viruses, parasites, and other toxins. Heavy downpours and flooding can spread bacteria from animal and human faeces into waterways and fields where crops are growing.

A nebulous ecoanxiety may be harder to deal with than facing the harsh reality of climate change

Speaking to the annual meeting of the Irish Medical Organisation earlier this year, Dr Ina Kelly, Consultant in Public Health Medicine in HSE Midlands, emphasised the particular vulnerability of Ireland to climate-induced waterborne disease.

“We have very significant vulnerabilities to climate change: for example, our susceptibility to serious waterborne disease from severe rainfall events is very high, with 170,000 private wells around the country providing untreated and sometimes contaminated drinking water; drought can also have a huge effect on farmers, who themselves are under pressure to consider the impacts of cattle density and the subsequent effect that has on our carbon emissions and on water contamination,” she said.

It’s strange, but reflecting back on our brush with climate-change reality, it was easier to cope with than the everyday sense of despair that pervades the overall narrative.

A nebulous ecoanxiety may be harder to deal with than facing the harsh reality of climate change.