What Is Planetary Health?

Brain Health

Our environment shapes neurological function and mental well-being, while resilient brains empower societies to adapt to and mitigate planetary challenges.

1 in 4 dementia deaths worldwide, approximately 626,000 deaths each year, is attributable to air pollution.

Brain health sits at the heart of Planetary Health, reflecting the dynamic relationship between human biology, social systems, and the environments we depend on to survive and thrive. The brain, our organ of cognition, emotion, behavior, and social connection, is uniquely sensitive to environmental conditions shaped by how we steward the planet. Rising temperatures, air and water pollution, extreme weather events, food and water insecurity, ecosystem degradation, and exposure to environmental toxins all affect neurological function, cognitive performance, and mental health across the lifespan.

20-30 minutes in natural environments can significantly improve attention, working memory, and executive function, compared with urban settings.

At the same time, healthy brains enable learning, creativity, cooperation, and collective decision-making, capacities that societies need to adapt to environmental change, design sustainable systems, and respond to crises. When environmental degradation undermines brain health, it weakens individual well-being, social cohesion, productivity, and communities’ ability to respond effectively to planetary challenges. This makes brain health both a vulnerability and a leverage point within the Planetary Health framework.

Our Brain Under Environmental Stress

Scientific evidence increasingly shows that environmental stressors act on the brain through interconnected biological, psychological, and social pathways. Heat stress disrupts sleep, cognition, and mental health; air pollution accelerates cognitive decline and increases the risk of dementia and neurodevelopmental disorders; extreme weather events drive trauma, displacement, and long-lasting effects on mental and cognitive health. These risks are not evenly distributed. Children, older adults, people with pre-existing neurological or mental health conditions, and communities facing socioeconomic disadvantage bear a disproportionate burden. A Planetary Health approach therefore requires centering on equity, prevention, and resilience.

Planetary Health Solutions for Brain Health

Crucially, many Planetary Health solutions are also brain-protective solutions. Cleaner air, climate-resilient food systems, access to green and blue spaces, urban tree canopies, reduced noise and heat exposure, and stronger social infrastructure all support cognitive function, emotional well-being, and neurological health while delivering environmental co-benefits. By explicitly integrating brain health into Planetary Health research, policy, and practice, we can better capture the full human benefits of environmental action and design interventions that strengthen both people and planet.