The Global Climate–Pollution Risk Atlas

Each country receives three scores, all percentile ranks among the 157 countries. Climate hazard combines the number of days with a heat index of 35 °C or more with the worst of its flood, cyclone and drought hazard scores from the INFORM Risk Index. Pollution exposure combines population-weighted outdoor PM2.5 with the share of people cooking with polluting fuels. The coping gap is INFORM's lack of coping capacity, which reflects governance, disaster-risk management, infrastructure and access to health care. The composite is the weighted mean of the three.

With equal weights, the 36 countries scoring above 66.7 — the top third of the possible range — hold 3.0 billion people, 37% of the total. They run from Chad, Niger, Mali, Mauritania and Sudan across the Sahel, through Nigeria, Benin, Cameroon and the Democratic Republic of the Congo, to Afghanistan, Pakistan, India, Nepal, Bangladesh and Myanmar. Thirty-eight countries are above the median on all three scores at once. The bivariate chart shows each country by hazard and pollution, with darker, more opaque bubbles where the coping gap is larger.

The weights change the map in instructive ways. Tripling the weight on outdoor PM2.5 brings Iraq and Bolivia into the top 30; tripling household smoke brings in Liberia, Mozambique and Madagascar at the expense of Syria, India and Senegal; tripling water hazard adds Liberia, Uganda, Mozambique, Iraq and Zimbabwe; tripling the coping gap shifts the list toward fragile, low-income states such as Sierra Leone and Madagascar and pushes out Bangladesh and India, whose risks come from hazard and pollution rather than weak coping. The core — the Sahel, Nigeria, Sudan, the Democratic Republic of the Congo and Pakistan — stays in the top 30 under every one of these weightings.

Behind each composite score sit four pathways. Outdoor PM2.5 comes from power plants, industry, traffic, crop and forest fires, household fuels burned outdoors, and desert dust; it is highest in South Asia, the Middle East, West Africa and parts of East Asia. Household smoke comes from cooking with wood, charcoal, dung, crop residues and kerosene, and affects 2.0 billion people in these countries, about half of them in sub-Saharan Africa. Extreme heat is measured by days with a heat index of 35 °C or more, which combine temperature and humidity; the population-weighted average is about 20 days a year. Water-related hazards — floods, cyclones and drought — are taken from the INFORM Risk Index.

The chart profiles the 20 highest-risk countries, showing how much each pathway and the coping gap contributes. Sahelian countries such as Chad score high on every pathway and on the coping gap. Bangladesh and Pakistan combine outdoor pollution among the world's highest with extreme humid heat and floods, but a moderate coping gap. The Democratic Republic of the Congo and the Central African Republic are driven by cooking smoke, dirty air and very weak coping capacity rather than by heat. Just outside the top 20, India combines outdoor pollution, heat and flood hazard in the top tenth of countries with a moderate coping gap.

Heat is rising fastest where humidity is high. Days with a heat index of 35 °C or more increased by about eight a year on a population-weighted basis between 1981–2010 and 2015–2024, and by more than 20 in 14 countries; Bangladesh added about 49, Kuwait 39 and Cambodia 35. Because the heat index captures humidity, these increases are largest along tropical coasts and river plains, where heat combines with crowded housing and, often, the most polluted air.

The composite layer follows the weights set in section 1. The bivariate layer colours each country by its climate-hazard and pollution-exposure thirds at once: teal where hazard is high and pollution low, red where pollution is high and hazard low, and deep slate where both are high. The three single-dimension layers show hazard, pollution exposure and the coping gap separately.

The opportunity layer highlights the countries where population-weighted PM2.5 is at least 25 µg/m³, shaded by their coal CO₂ emissions; all other countries are grey. It shows at a glance that the largest coal emitters with high exposure are few — China and India above all, followed by Viet Nam, Türkiye, Pakistan, Mongolia and Bangladesh.

Hover over a country to see its card: outdoor PM2.5 in 2024 and ten years earlier, the share and number of people cooking with polluting fuels, heat days and their increase, flood, cyclone and drought hazard, the coping gap, CO₂ from coal, oil and gas, methane, and coal's share of electricity, with a bar showing the four pathway percentiles.

Grouping countries by income shows how differently the pathways and the emissions are distributed. Low-income countries hold a small share of people and essentially none of the world's coal CO₂, yet 84% of their people cook with polluting fuels and their outdoor air averages about 30 µg/m³ — much of it desert dust and biomass smoke. Their exposure comes from poverty and geography, not from the emissions that drive climate change.

Lower-middle-income countries have the highest outdoor pollution, about 42.6 µg/m³ weighted by population, and the most heat, about 44 days a year above a 35 °C heat index, and still more than a third of their people cook with polluting fuels — the combination that makes India, Pakistan, Bangladesh, Nigeria and Egypt so exposed. Upper-middle-income countries emit about 69% of the world's coal CO₂, overwhelmingly from China, with lower exposure on average after a decade of air-quality policy; high-income countries emit most per person, 9.8 tonnes of CO₂ against 0.3 in low-income countries, and breathe the cleanest air.

The mismatch defines the policy problem. Where emitters and exposed people are the same — coal-burning, polluted middle-income economies — climate and clean-air policy reinforce each other domestically. Where they are different — poor, exposed countries whose climate hazards are driven by others' emissions — the response has to combine adaptation finance, clean household energy and support from high emitters. The chart compares each income group's share of people, coal CO₂, methane, people breathing 35 µg/m³ or more, and people cooking with polluting fuels.

Co-benefits are largest where the sources of warming and of dirty air are the same and sit next to many people. The 60 countries where population-weighted PM2.5 is at least 25 µg/m³ hold 5.0 billion people and emit 74% of the world's coal CO₂ — 11.4 of 15.5 billion tonnes — as well as 49% of its methane and about half of all greenhouse gases. China (8.7 billion tonnes of coal CO₂, 31 µg/m³) and India (2.0 billion tonnes, 44 µg/m³) dominate, followed by Viet Nam, Türkiye, Pakistan, Mongolia and Bangladesh. Phasing down unabated coal in these economies is the single largest climate–air co-benefit available.

Methane and black carbon offer faster returns. Shindell and colleagues identified 14 measures — capturing methane from oil and gas, coal mines and landfills, cutting rice-paddy and livestock emissions, and replacing traditional stoves, brick kilns and diesel engines — that would reduce warming by about 0.5 °C by 2050 and avoid 0.7–4.7 million premature deaths a year, while raising crop yields by 30–135 million tonnes. China, India, Pakistan, Nigeria, Iran and Iraq are among the large methane emitters with high exposure. More broadly, Vandyck and colleagues estimated that a 2 °C-compatible pathway would avoid 0.7–1.5 million air-pollution deaths a year by 2050, with health benefits that could offset the cost of climate policy.

Where emissions are low and exposure high — most of sub-Saharan Africa and parts of South Asia — the priority is household energy and adaptation. Two billion people still cook with polluting fuels, 1.45 billion of them in countries with above-median climate hazard; clean cooking cuts household smoke, the black carbon and methane from incomplete combustion, and the pressure on forests. Heat-health action plans, flood protection and drought resilience are the adaptation side of the same hotspots. And China's experience — satellite-based PM2.5 down from 52 µg/m³ in 2014 to 31 in 2024 — shows that concentrated action on coal and industry can transform exposure within a decade.

The atlas covers 157 countries with at least 1 million people and complete data. Outdoor PM2.5 is the population-weighted satellite-based estimate for 2024 (SatPM, Washington University in St. Louis, via Our World in Data). Household smoke is 100 minus the share of people with access to clean cooking fuels and technologies (WHO, via World Bank WDI, latest year). Extreme heat is the average number of days a year with a daily maximum heat index of at least 35 °C in 2015–2024, and its change from 1981–2010, from ERA5 country averages published by the World Bank Climate Change Knowledge Portal. Water-related hazard is the highest of INFORM Risk 2026's river or coastal flood, tropical cyclone and drought scores; the coping gap is INFORM's lack of coping capacity.

Each measure is converted to a percentile rank among the 157 countries. Climate hazard is the weighted mean of the heat and water percentiles, pollution exposure the weighted mean of outdoor PM2.5 and household smoke, and the composite the weighted mean of hazard, pollution and coping gap; all weights default to one. Emissions come from Our World in Data's CO₂ and greenhouse-gas dataset for 2023 (coal, oil and gas CO₂; methane in CO₂-equivalents; total greenhouse gases), and coal's share of electricity from its energy dataset.

Limitations: percentile ranks are relative; national averages hide subnational hotspots; heat-index days are averaged over each country's territory, not its population; INFORM scores mix hazard and exposure; ozone, wildfire smoke, water pollution and sea-level rise are not included; emissions are territorial, not consumption-based. Related reports: the pollution–climate feedback system, heat and air pollution and the unequal geography of air pollution exposure.