Health Damages From Climate Change Are Increasing Faster: Report
The negative health impacts of climate change are not only increasing but doing so at a faster pace than a decade ago, according to a major global assessment released Wednesday.
The 10th annual Lancet Countdown report — by an international collaboration of scientists that tracks the relationship between global warming and human health — compares the decade since the signing of the Paris climate agreement with the decade before. It finds that several major health threats, including deadly heat and drought, increased more rapidly after the accord, even as countries ramped up investments in clean energy and protecting people from climate hazards.
The report comes after a summer when heat waves in Europe killed tens of thousands and just ahead of the United Nations COP31 climate summit in Turkey.
Annual heat-related deaths were nearly 36% higher in the period 2016 through 2023 than from 2006 through 2015, the analysis finds. In 2023 alone, heat was linked to an estimated 710,000 deaths worldwide. Heat exposure is also trimming the gross domestic product of countries around the globe, with Southeast Asia and Africa the worst-affected regions.
For the first time, the Countdown calculated how many heat-related deaths could be attributed to human-caused climate change. The researchers estimate warming was responsible for more than 70% of those deaths in 2023 and almost 3 million from 2016 through 2023.
Read more: EU’s Insurance Watchdog Warns of Risks Tied to Extreme Heat
In addition to heat exposure, water-related risks are growing. Nearly 52% of the world’s land experienced extreme drought for at least one month in 2025, the second-highest level on record. A satellite analysis found long-term shifts toward wetter or drier conditions across 80% of global land since 2003, changes that can threaten crops, drinking water and sanitation. The current El Niño is set to exacerbate drought conditions in parts of the world into next year.
“The climate crisis is having profoundly damaging consequences for human health,” Simon Stiell, executive secretary of the United Nations Framework Convention on Climate Change, said in a statement. He cited impacts ranging from “deadly heat waves and floods to food insecurity, pollution and more disease.”
The new report was produced by 146 researchers from dozens of institutions. Researchers tracked 54 measures of the health effects of climate change and efforts to address them. The authors call for governments to put health considerations at the center of climate and energy policy.
They also conclude that steps to address climate change are producing health benefits: Cleaner air prevents about 323,000 deaths annually in at least 77 countries where air pollution from fossil fuels has declined since 2016. But fossil fuels still supply more than 80% of global energy, and fossil-fuel-related air pollution kills an estimated 2.7 million people per year.
Health systems have also become better prepared. Fifty-six of the World Health Organization’s 194 member states now have national plans for adapting health services to climate change, up from 14 in 2015.
Emily Bancroft, chief executive officer of Health Care Without Harm, an organization that works to reduce the health sector’s environmental impact, said finding the money to implement those plans remains a major challenge for countries.
“The amount of dialogue and discourse around this work is very encouraging,” she said. “There is a real gap in the financing to get there.”
Photograph: Visitors shade themselves beneath umbrellas during high temperatures in Barcelona, Spain, on Aug. 5, 2026; photo credit: Angel Garcia/Bloomberg
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