Climate change could significantly widen global mortality inequality, with low and middle-income countries expected to bear a disproportionate share of heat-related deaths, according to a new report by the Climate Impact Lab.
The report projects that by 2050, poor countries could experience up to ten times more temperature-related deaths than wealthy nations, highlighting stark disparities in both exposure and adaptive capacity. The study is the first in a series to identify where and what climate adaptation investments will be most beneficial.
Globally, over 90 percent of these additional deaths linked to rising temperatures are expected to occur in low and middle-income countries. Limited access to cooling infrastructure, healthcare, and climate-resilient urban planning is likely to constrain their ability to cope with intensifying heat.
“This report uncovers one of climate change’s cruelest ironies—it is projected to kill millions of people in the countries that have generally done the least to cause it,” said Michael Greenstone, co-founder of the Climate Impact Lab and director of the Institute for Climate and Sustainable Growth and the Energy Policy Institute at the University of Chicago.
The findings from the report underscore the inequality of climate change. The issue is not only that warmer regions are set to experience higher mortality than cooler ones, but also that the greatest impacts are projected to fall on regions that are both hotter and poorer, as they have fewer resources for adaptation.
India: Sharp Regional Variations
In India, the average projected increase in mortality is estimated at 2.4 deaths per 100,000 people, ranking the country 76th among 241 regions. However, this country-level average masks sharp regional disparities.
- Regions with the largest decrease in projected temperature-related mortality are in the southwest, east, and extreme north.
- Region with the largest decrease: -25 deaths/100,000 in Padam, Kashmir
- Regions with the largest increase in projected temperature-related mortality are in the northwest and north-central
- Region with the largest increase: 26 deaths/100,000 in Karanpur, Rajasthan
In some of the hardest-hit regions, the projected rise in heat-related mortality (~23-25 additional deaths/100,000) is comparable to current death rates from major diseases such as tuberculosis and diabetes, the report notes.
Inequality at the Core
The report underscores that climate change is not only an environmental challenge but also a deeply unequal social and economic crisis. Poorer regions, often already exposed to higher baseline temperatures, face structural barriers to adaptation.
“The regions where increases in mortality are highest are also those with few resources, limited government capacity, and a weak history of attracting international private investment,” says Tamma Carleton, Faculty Head of Research for the Climate Impact Lab and an Assistant Professor at the University of California, Berkeley.
The report emphasises that targeted adaptation investments can substantially save lives, as temperature-related mortality will depend both on the direct impacts of a warming climate and on the investments that people and governments make to protect human health.
Policy Implications
For India, the findings highlight the need for region-specific climate adaptation strategies, particularly in heat-prone northern and western regions. Strengthening rural healthcare, integrating climate resilience into urban planning, and expanding heatwave early warning systems will be critical.
This report identifies the regions around the world where climate adaptation offers the greatest opportunity to save the most lives, based on the Climate Impact Lab’s projections of temperature-related mortality in 2050.