Heat inequality: global warming set to drive mortality surge in poor nations while saving lives in rich countries; new study maps stark divide in climate-driven deaths by 2050.
A warming planet is not affecting everyone equally. New research shows that climate change is reshaping global mortality patterns in sharply uneven ways — reducing deaths in colder, wealthier regions while increasing them dramatically across hotter, lower-income countries.
The findings, from the Climate Impact Lab at the University of Chicago, offer the first detailed projections of how rising temperatures will influence mortality based on localized data. The results highlight a widening global health divide, driven not only by geography but by income and access to adaptation.
RELEVANT SUSTAINABLE GOALS
Cooling Benefits in Wealthy, High-Latitude Regions
In cooler parts of the world, rising temperatures may bring unexpected benefits. Countries in mid-to-high latitude regions — including Scandinavia — are projected to see declines in temperature-related mortality.
In some cases, deaths could fall by more than 70 per 100,000 people. Similar trends are expected in places like northeastern Russia’s New Siberia Islands, the North Slope of Alaska, Banff in Canada and Oslo, where warming reduces the risks associated with extreme cold.
These gains are driven by fewer cold-related deaths, a shift that disproportionately benefits wealthier nations with colder climates.
Rising Heat, Rising Deaths Across the Global South
The picture is starkly different across much of the developing world.
In regions already exposed to high temperatures — including Southwest Asia, Northern Africa and the Middle East — rising heat is projected to significantly increase mortality. The Sahel region stands out as one of the most vulnerable.
Countries such as Niger and Burkina Faso could see mortality increases exceeding 60 deaths per 100,000 people, surpassing current malaria death rates. In Djibouti, projected increases of around 55 deaths per 100,000 people would match the country’s existing HIV/AIDS mortality rate.
Pakistan is expected to face one of the most severe national impacts, with a projected increase of 51 deaths per 100,000 people by 2050 — comparable to the current toll from stroke.
Cities on the Front Lines of Extreme Heat
Urban areas, particularly in South Asia, are expected to bear some of the heaviest burdens.
While cities in wealthier countries will also see rising deaths — with projections of about 600 additional deaths annually in Phoenix and 525 in Madrid — the scale in developing regions is far greater.
Faisalabad in Pakistan alone could experience approximately 9,400 additional deaths each year due to rising temperatures.
Across global urban centers, more than 100,000 additional lives are projected to be lost annually as temperatures rise. One-third of these deaths are expected to occur in Pakistani cities.
In many cases, heat-related mortality will exceed current death rates from major diseases such as tuberculosis, chronic obstructive pulmonary disease (COPD) and stroke.
Asia’s Growing Exposure to Climate Mortality
The risks extend across Asia’s rapidly growing cities.
Of more than 300 cities in the region, 95 are projected to experience increases in temperature-related mortality of at least 10 deaths per 100,000 people. Of these, 56 are in China.
In these densely populated areas, additional deaths linked to climate change are expected to match the number of lives currently lost to esophagus and colon cancer.
The study underscores a profound inequality: those least responsible for greenhouse gas emissions are expected to suffer the greatest consequences.
Globally, an estimated 391,000 people in lower-income countries are projected to die each year due to shifting temperatures by 2050. In contrast, higher-income countries — with roughly similar population sizes — are expected to see about 39,000 deaths.
The disparity also appears between countries with similar climates but different income levels. For example, Djibouti’s projected increase in mortality is more than double that of Kuwait.
“All but two of the 20 countries with the biggest net improvements are high-income, and 16 of the 20 countries facing the most new deaths are lower-income,” the research finds.
Michael Greenstone, a University of Chicago economist and co-director of the Climate Impact Lab, said the results reflect a troubling imbalance. “The extra deaths are all going to occur in places that contributed very little” to the emissions driving global warming, he said.
Adaptation Measures Could Change the Outcome
Despite the scale of the projected impacts, the study emphasizes that outcomes are not fixed.
Investments in adaptation — including air conditioning, cooling centers and other protective measures — can significantly reduce heat-related mortality. The research highlights the importance of targeted adaptation strategies, particularly in regions facing the highest risks.
However, current levels of climate finance fall far short of what is needed.
According to the United Nations Environment Programme, developing countries will require between US$310 billion and US$400 billion annually by 2035 for climate adaptation. Present funding flows are estimated to be 12 times lower than required.
At the COP27 climate talks, the United Nations established a Loss and Damage Fund to support vulnerable countries. More recently, at COP30, countries set a target to triple adaptation finance to around US$120 billion annually by 2035.
Critics argue that even this level of funding remains insufficient and stress the need for mechanisms that ensure resources reach communities most exposed to climate risks.
A Defining Challenge for Global Climate Policy
The study arrives as record-breaking heat waves affect large parts of the world and evidence continues to mount that global warming is accelerating.
Researchers say the findings are intended to help cities and communities better understand and respond to rising risks.
But they also deliver a broader message: climate change is not only an environmental issue but a deeply unequal public health crisis.
As one researcher put it, “Alarm bells are ringing.” Without significant investment in adaptation — particularly in the Global South — the gap in climate-related mortality between rich and poor countries is set to widen in the decades ahead.
