What is the link between health equity and climate change?

Health equity and climate change are linked because climate hazards such as heat, wildfire smoke, floods and infectious disease do the most harm to groups that already have worse health and fewer resources. WHO lists women, children, ethnic minorities, poor communities, migrants, older people and people with underlying conditions among those disproportionately affected.

Who is most vulnerable to the health impacts of climate change?

Vulnerability to climate-related health harm combines physiology and circumstance. WHO notes that heat risk depends on age and health status as well as occupation and socioeconomic conditions, so older adults, people with chronic illness, outdoor workers and people experiencing homelessness are among those at highest risk during extreme heat.

How many people die from extreme heat each year?

The 2025 report of the Lancet Countdown on health and climate change estimates that heat-related deaths have reached about 546,000 a year worldwide, with the death rate up 23% since the 1990s. WHO notes that heat stress is a leading cause of weather-related deaths and can worsen cardiovascular disease, diabetes and asthma.

What is Health Equity and Climate?

Health equity and climate is the study and practice of how climate change affects health unequally, and of designing climate and health policy that narrows those gaps instead of widening them. WHO defines equity as the absence of unfair, avoidable or remediable differences among groups of people, and says health equity is achieved when everyone can attain their full potential for health and well-being.

The lens asks a sharper question than climate and health in general. The broader field counts the total burden of heat, smoke, floods and disease; an equity lens asks who carries that burden, why, and whether responses reach them. WHO says health and health equity are shaped by the conditions in which people are born, grow, live, work, play and age, which is why income, housing, occupation and discrimination matter as much as geography in who is harmed.

The topic sits between two related ideas. Environmental justice focuses on the unequal siting of pollution and hazards, while equitable climate adaptation applies the same lens to resilience investment. Health equity and climate uses health outcomes as the yardstick for both.

Why It Matters

The burden is large and unevenly shared. WHO's climate change fact sheet projects about 250,000 additional deaths a year between 2030 and 2050 from undernutrition, malaria, diarrhea and heat stress alone. It says these risks fall disproportionately on women, children, ethnic minorities, poor communities, migrants or displaced people, older people and people with underlying health conditions.

Heat is the clearest case. The 2025 report of the Lancet Countdown on health and climate change estimates heat-related deaths at 546,000 a year, with the death rate up 23% since the 1990s. The same report attributes an estimated 2.52 million deaths in 2022 to outdoor air pollution from fossil fuels, a reminder that the causes of warming also harm health directly.

Work is a major pathway. The International Labour Organization estimated in 2024 that more than 2.4 billion of the world's 3.4 billion workers are likely to be exposed to excessive heat on the job, and that excessive heat causes 22.87 million occupational injuries and 18,970 deaths a year. The ILO notes that workers are among the most exposed to climate hazards yet often have no choice but to keep working in dangerous conditions.

Local data show how sharply risk concentrates. Maricopa County's 2025 heat deaths report, covering the Phoenix area, counted 430 heat-related deaths, 49% of them among people experiencing homelessness. In deaths indoors, an air conditioner was present in 94% of cases but not working in 72% of those, which makes cooling repair and energy poverty health issues.

Companies are saying less about this, not more. The Lancet Countdown found that only 51% of companies referred to the health dimensions of climate change in their UN Global Compact reports in 2024, down from 63% in 2023.

How It Works / Key Components

Three drivers of unequal harm

WHO's heat and health fact sheet describes heat vulnerability as shaped by physiological factors, such as age and health status, and exposure factors, such as occupation and socioeconomic conditions. The same logic applies to most climate hazards.

Driver	What it means	Examples
Exposure	How much of a hazard reaches a person	Outdoor work, hotter or flood-prone neighborhoods, living unsheltered
Sensitivity	How strongly the body reacts	Older age, heart, lung or kidney disease, diabetes
Capacity to cope	Resources to avoid harm or recover	Working and affordable cooling, health care access, transport, social contact

The main pathways

Heat: hot neighborhoods, poor housing and outdoor work compound one another. WHO notes that lost green space and heat-trapping materials such as metal roofs amplify exposure in cities, the mechanism behind the urban heat island effect.
Air quality: fossil fuel combustion and wildfire smoke worsen heart and lung disease.
Floods and storms: injuries, displacement, mold and interrupted care, including power loss for home medical equipment.
Disease, food and water: shifting ranges for mosquito-borne illness and disrupted food and water supplies.

Measuring it

Equity-focused monitoring breaks out deaths, emergency visits and illness by age, income, race and ethnicity, housing status, occupation and neighborhood. Surveillance that records details such as housing status and whether a home had working cooling, as Maricopa County's does, turns general concern into specific interventions.

What narrows the gap

Effective responses match the driver. Heat action plans with early warnings and outreach to people living alone address capacity, while worker heat protections, shade and tree canopy reduce exposure. Housing and energy measures, such as cooling repair, efficient heat pumps and protection from utility shutoffs during heat waves, close the gap between having cooling and being able to use it.

Council Fire's Approach

Council Fire brings a health lens into climate resilience planning and sustainability strategy. We map heat, flood and air-quality exposure alongside the health, housing and income data that shape sensitivity and capacity, so plans target the people most at risk rather than the average resident. Stakeholder engagement includes public health agencies, community health workers and organizations that reach residents rarely heard in planning, such as outdoor workers and unhoused people. Our storytelling work translates risk into guidance people can act on, and when a program needs it, we build dashboards through Council Fire Labs that track outcomes and program reach by neighborhood and group.

Frequently Asked Questions

Why is air conditioning a health equity issue?

In hot places, working and affordable cooling separates people who ride out a heat wave from those who do not. Maricopa County's data show that in most indoor heat deaths an air conditioner was present but not working, which points to repair programs, efficient replacement units and shutoff protections. Pairing cooling with efficiency and clean power keeps it from raising bills or emissions.

What can employers do about climate-related health risks for workers?

Employers can adopt heat plans for outdoor and poorly cooled indoor work that cover acclimatization for new staff, water, rest and shade, earlier shifts on hot days and monitoring for symptoms. The ILO's 2024 report found that occupational safety protections have struggled to keep up with climate risks, so waiting for regulation leaves workers exposed. Contractors and suppliers doing the same work deserve the same protections.

Does cutting emissions improve health equity?

It can, especially when cuts happen where pollution is concentrated. Retiring or cleaning up combustion sources near homes, schools and clinics delivers health gains first to the people who breathe that air. Measures such as electrifying buses and trucks can reduce both greenhouse gases and local air pollution at once.

What is Health Equity and Climate?