When we think about the effects of the climate crisis on health, we think of heat waves, breathing difficulties caused by pollution, diseases aggravated by extreme temperatures. Much more rarely do we think about what happens in our mind.
Yet, the environment in which we live also influences our psychological balance, the functioning of the brain and can increase the risk of developing mental disorders. Not only when we are involved in a flood or other catastrophic event, but also through everyday exposures, such as traffic noise, polluted air, persistent heat and stressful conditions related to urban life.
What draws attention to this relationship is the first report of the Earth Brain Health Commissionan international commission made up of over 20 experts, including Cornelius Gross, director of EMBL Rome, published in the scientific journal Nature Mental Health.
The message from scientists is clear: we cannot continue to consider environmental protection and mental health protection as two separate issues. According to the Commission, in fact, extreme climate events, air and noise pollution, loss of biodiversity and social inequalities are associated with an increased risk of anxiety, depression, disorders linked to traumatic events and cognitive decline. The report also argues that within the next ten years, no major environmental intervention should be designed without also evaluating the possible consequences on people’s mental health.
How the environment can affect mental health
The relationship between environment and mental health is much more complex than it might seem. There is no single responsible factor, but a combination of exposures that can overlap and influence each other.
Let’s think, for example, of those who live in a densely urbanized neighborhood, crossed by traffic, with few trees and very few green spaces. During the summer that same person may be simultaneously exposed to high temperatures, noise, air pollution and unfavorable housing conditions.
These are not necessarily isolated risks. As the report highlights, many environmental factors are concentrated in the same territories and affect the same populations, through biological, psychological and social mechanisms.
Extreme weather events represent one of the most obvious manifestations of this relationship. Floods and other disasters can compromise people’s safety, destroy homes, disrupt daily life and force entire communities to relocate. The material consequences can be accompanied by psychological ones, with an increased risk of anxiety, depression and disorders linked to traumatic experiences.
But air pollution, noise and urban stress are also among the exposures considered by the Commission. Similarly, the loss of biodiversity is recognized as one of the environmental transformations that can impact mental well-being.
The issue also concerns all ages. Environmental exposures can interact with health throughout the life course, from prenatal development to old age, with possible different consequences depending on the developmental stage and individual conditions.
This, however, the authors point out, does not mean that it is already possible to attribute every mental disorder to a specific environmental cause.
Mental health must enter into climate policies
According to the Earth Brain Health Commission, psychological well-being is also expected to become a key indicator in climate and urban policies, starting from 2027.
Environmental change is not just an ecological or economic problem. It reaches the brain, underlines Gunter Schumann, president of the Commission.
The objective is to allow governments to evaluate, through scientific data, the effects of environmental interventions on mental health. Children, older adults, people with disabilities and economically disadvantaged communities may be more exposed to risk and have fewer resources to protect themselves.
Environmental interventions also risk widening inequalities: new parks, trees and programs against the heat can especially benefit the wealthier neighborhoods, leaving behind those who need them most.
For this reason, the Commission asks to give priority to the most vulnerable populations, involving them directly in decisions. It also proposes that at least 30% of the recommended research be led by partners from low- and middle-income countries and affected communities.
From research to action: eight commitments for the next decade
The report identifies eight areas of intervention to transform scientific knowledge into concrete prevention tools. Among the most significant proposals are:
On this last point, the Commission proposes the creation of an Earth–Brain–Health Research Fund and a Global Observatory, to be made operational by 2028. The two structures would have the task of coordinating studies, monitoring progress and publishing a report on the implementation of commitments every year.
Another particularly concrete indication concerns warning systems: to date, warnings for extreme heat or poor air quality are mainly designed to prevent physical damage. Scientists ask that they also be linked to prevention and mental health support tools, so as to broaden the protection offered to exposed populations.
According to the Commission, the problem is not so much the lack of scientific knowledge, but its use. We already have data on climate, pollution and health, but they are often analyzed separately, making it difficult to understand how different environmental factors affect mental well-being.
Furthermore, much of the research comes from wealthier countries, while many of the populations most exposed to environmental change remain under-represented in studies.
Reducing pollution, combating extreme heat and making cities greener and more livable also means investing in the prevention of mental health risks. The challenge will be to measure these benefits and ensure that they reach everyone, not just those living in the most privileged areas.
Because a truly sustainable city is not only one that pollutes less, but also one in which people can live better, physically and mentally.
