A warming world is reconfiguring the global map of mortality – saving lives in colder regions while sharply increasing deaths across already hot, poorer countries.
While countries in cooler, mid-to-high latitude regions such as Scandinavia are projected to see temperature-related mortality rates fall – by more than 70 deaths per 100,000 people in some cases – much of the developing world faces the opposite trajectory, according to new research from the Climate Impact Lab at the University of Chicago.
The study marks the first projections of rising temperature’s impacts on mortality, based on localised data and highlights the extent to which adaptation measures can reduce heat-related mortality, including investments in air conditioning, cooling centres and other adaptive measures.
In hotter regions across Southwest Asia, Northern Africa, and the Middle East rising temperatures are expected to drive significant increases in heat-related deaths. Nowhere is this more acute than in the Sahel, where countries such as Niger and Burkina Faso could see mortality increases exceeding 60 deaths per 100,000 people – surpassing today’s malaria death rates on the continent.
Pakistan, the country with the most cities affected by warmer climes globally, is projected to experience a net increase in temperature-related mortality of 51 deaths per 100,000 people by 2050 – comparable to the current toll from stroke.
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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.
Tamma Carleton, head of research, Climate Impact Lab
Climate mortality imbalance
The study’s authors suggest that those least responsible for global emissions are likely to bear the greatest burden.
While extreme heat will increase deaths, fewer people are expected to die from extreme cold. But these gains are concentrated in wealthier, cooler regions – leaving poorer, hotter countries with a net increase in mortality.
Globally, an estimated 391,000 people in lower-income countries are projected to die each year due to shifting temperatures, compared to about 39,000 in higher-income countries – despite both groups having roughly similar population sizes.
Change in region-level net mortality rates (deaths per 100,000 people) in 2050 compared to the 2001-2010 average due to climate change. Source: Climate Impact Lab
The disparity is also evident between countries with similar climates but different income levels. In East Africa, Djibouti is projected to see an increase of 55 deaths per 100,000 people due to rising temperatures – on par with its current HIV/AIDS mortality rate. By contrast, wealthier Kuwait is expected to see about 25 additional deaths per 100,000, less than half its current heart disease mortality rate.
Singapore is an example of a tropical country that is vulnerable to extreme temperatures, but has the capital to spend on adaptation measures.
Countries with a projected net increase and decrease in temperature-driven mortality by 2050. Source: Climate Impact Lab
Urban areas, particularly in South Asia, are expected to face some of the most severe impacts.
While wealthier cities such as Phoenix in the United States and Madrid in Europe are projected to see additional annual deaths in the hundreds – around 600 and 525, respectively – Faisalabad in Pakistan alone could see an increase of approximately 9,400 deaths per year due to rising temperatures.
Across the world’s urban centres, more than 100,000 additional lives are projected to be lost annually due to temperature changes, with one-third of those deaths occurring in Pakistani cities. In many of these cities, the increase in heat-related mortality is expected to exceed current death rates from major diseases such as tuberculosis, chronic obstructive pulmonary disease (COPD) and stroke.
In Asia, 95 out of more than 300 cities in the region will experience an increase in temperature-related mortality of at least 10 deaths per 100,000 with 56 of them in China. Additional deaths due to climate change in those heavily populated areas of China will be on par with the number of lives currently lost to both esophagus and colon cancer.
The adaptation imperative
Where and how the world invests in climate adaptation now will have consequences for climate-related mortality in the decades ahead, the study said.
While there has been a push to aid climate-vulnerable countries through mechanisms such as the United Nations’ Loss and Damage Fund, created at the COP27 climate talks in 2022, the supply of adaptation finance will fall far short of the scale of adaptation investment needs, the report warned.
Developing countries will need US$310–$400 billion annually by 2035 for climate adaptation, with current financing needs 12 times greater than present flows, according to United Nations Environment Programme.
At COP30 in Brazil, countries set a goal of tripling international adaptation finance – aiming to raise funding to roughly US$120 billion annually – by 2035. Critics have suggested that the amount is insufficient, and mechanisms are needed to ensure climate finance reaches local communities on the hard edge of climate change.
