loading . . . ‘Millions of Avoidable Deaths’: Climate Change Health Harms Reach Unprecedented Levels Heat waves, extreme drought and deadly wildfire smoke are just some of the climate-related health hazards that have reached record levels of harm, according to the latest report from a global collaboration of leading scientists and public health professionals.
The Lancet Countdown is an annual breakdown of how climate change impacts public health around the world. It is authored by 128 global experts and headquartered at University College London, and produced in collaboration with the World Health Organization.
The ninth edition of the report, published Tuesday, found that 13 out of 20 metrics used to track the health impacts of climate change have reached unprecedented levels, including heat wave deaths in vulnerable populations, risks of dengue fever transmission and deaths from air pollution caused by wildfire smoke.
The authors summed up the situation as “a world in turmoil.”
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“The delays in delivering climate action that we are seeing so far are increasingly costing lives and costing livelihoods,” said Marina Romanello, biomedical scientist and executive director of the Lancet Countdown, at a press briefing announcing the report. “We’re seeing millions of deaths that are occurring needlessly every year because of our persistent fossil fuel dependence, because of our delay in mitigating climate change and our delays in adaptation to the climate change.”
As has been well-documented for years, the health burdens of climate change fall disproportionately on the world’s poorest countries, which have contributed the least to global warming. Meanwhile, there’s a global reversal afoot in government and corporate responses to the crisis. By one metric, researchers found that the percentage of governments that mentioned the relationship between health and climate change in statements at the start of the annual U.N. general assembly declined from 62 percent in 2021 to 30 percent in 2024, with the biggest emitters driving the loss of engagement.
This year, the U.S.—the world’s largest historical emitter of greenhouse gases—has withdrawn from the Paris Agreement, dismantled climate and health research and slashed staff and programs at government agencies focused on health, climate and the environment. Researchers also wrote that the country’s withdrawal from the World Health Organization compounds global climate and health threats.
Opportunities for a just and “health-centered” transition to renewable energy, in line with the Paris Agreement, “remain largely untapped, resulting in millions of avoidable deaths yearly,” the report reads.
The Lancet report is published annually ahead of the U.N. climate summit. The 30th gathering will take place next month in Belém, Brazil.
As climate change becomes increasingly dire, Romanello warned that nations are not moving fast enough.
“We’re seeing that adaptation is becoming increasingly costly and increasingly challenging,” she said. “This reversal of commitments threatens to make adaptation practically impossible and probably unaffordable.”
Researchers acknowledged that the report paints an overall grim portrait of the state of climate and global health.
“The picture is quite bleak,” said Niheer Dasandi, a professor of global politics and sustainable development at the University of Birmingham and one of the report’s authors.
Still, Dasandi cautioned against falling into doomsday despair. While far greater action on climate adaptation and the energy transition is needed, every bit of progress to slow global warming is essential, he said.
“The notion of ‘all is lost,’ it’s not clear to me what that would really mean,” Dasandi said. “We don’t have much choice but to be optimistic. … If we consider a world where warming gets to 2.7 [degrees] versus, let’s say, 3.4, it’s a huge difference in what it means for people’s lives and people’s health.”
## **Climate Change Fuels Heat, Death and Disease**
Extreme heat is a growing threat worldwide, and it’s getting deadlier. Lancet Countdown researchers found that from 2020 to 2024, the average person globally experienced about 19 heat wave days per year—16 of which would not have happened without human-caused global heating.
The largest increases in heat wave exposure occurred in Africa, Asia and the Small Island Developing States, many of which are already facing other disproportionate climate burdens, from sea-level rise to dangerous storms. Island nations including Tuvalu, Fiji and Jamaica—the latter of which was hit Tuesday by an abnormally powerful hurricane—have been at the forefront of calls for wealthier nations to pay more into loss and damage funds to support countries at the frontlines of climate change.
Researchers found a 63 percent increase in heat-related deaths since the 1990s, resulting in an estimated 546,000 annual heat deaths from 2012 to 2021. Just under two-thirds of the world’s land area suffered from at least one month of extreme drought at some point last year, the highest percentage ever recorded and far above the mid-20th-century average.
Increased heat wave days and droughts in recent years have resulted in millions more people experiencing moderate or severe food insecurity than in previous decades.
Extreme heat poses myriad health harms, and researchers found that the increase in heat waves is decreasing the quality of people’s sleep, preventing healthy exercise habits and harming physical and mental health.
The impacts of heat are most severe for lower-income nations and people experiencing poverty in every country, said Ollie Jay, a professor of heat and health at the University of Sydney and one of the Lancet report’s authors.
“It’s been repeatedly demonstrated that those who are contributing the least to climate change are often suffering the greatest impacts, and that’s particularly relevant with respect to heat stress,” Jay said.
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Heat also leads to economic loss and decreased worker productivity: 2024 saw a record high of nearly 640 billion potential work hours lost, nearly double that of the 1990s, Lancet Countdown researchers wrote.
Right now, heat-related deaths can be preventable if treated promptly with cooling, hydration or other medical interventions. But parts of the Earth may be heading toward a physiological tipping point, Jay said, where people are met with a combination of temperature and humidity that is simply not survivable after a certain amount of time.
“We’re potentially reaching these limits in different parts of the world at an alarming rate,” Jay said. “It is a deep cause for concern.”
The estimated number of deaths that researchers attribute to air pollution from wildfire smoke hit a record high of 154,000 last year. Tiny, dangerous particulate matter created by wildfires can enter the lungs and bloodstream and cause damage throughout the body. Many more people, meanwhile, die every year due to air pollution from fossil fuel combustion.
In addition to extreme heat, air pollution and wildfire smoke, researchers found that vector-borne diseases like dengue fever and malaria are spreading faster and wider, and that bacterial diseases and pathogens are cropping up in new locations.
## **Fossil Fuel Expansion Threatens Health**
Fossil fuel giants like Shell, BP, ExxonMobil and Chevron have paused, delayed, or turned back previous commitments to reduce oil and gas production or increase renewable energy investments, while private banks ramped up lending to the fossil fuel sector by nearly 30 percent in 2024, the Lancet Countdown report said.
Meanwhile, the countries pumping out the most greenhouse gases are set to produce more than twice as much oil, gas and coal as allowed by the Paris Agreement targets aimed at averting the worst consequences of climate change.
In 2023, fossil fuel subsidies from the 87 countries that account for more than 90 percent of global greenhouse gas emissions reached $956 billion, a threshold second only to the previous year, when they reached $1.4 trillion, buoyed by energy price spikes after Russia’s invasion of Ukraine. Fifteen of those countries spent more on fossil fuel subsidies in 2023 than on health care, Lancet Countdown authors found. Five countries—Iran, Libya, Algeria, Venezuela and Uzbekistan—spent more than twice their health budget on these subsidies.
And the world does not have the energy or health care infrastructure to meet global needs: 745 million people worldwide lack electricity access, and about 1 billion—or an eighth of the world population—are served by health care facilities that lack reliable power.
> > “The overriding trend is that people are well aware of what’s going on, because they’re experiencing it, sadly, firsthand.”
>>
>> — Niheer Dasandi, a professor at the University of Birmingham
The continued expansion of fossil fuels is a threat to public health, Lancet Countdown’s Romanello said.
“This is a fundamental health determinant,” she said. “If we keep on enabling this expansion of fossil fuels, we know that a healthy future is not possible and that all of these environmental determinants of health will get much worse very, very fast.”
The report’s authors said awareness of climate health impacts may be growing among the public. For one, Google searches for climate change and health went up from 2023 to 2024, particularly in countries most impacted by climate change. This engagement may be driven by more people experiencing climate effects such as disasters, said Dasandi of the University of Birmingham.
“The overriding trend is that people are well aware of what’s going on, because they’re experiencing it, sadly, firsthand,” he said.
From 2010 to 2022, researchers found that a global shift away from coal resulted in 160,000 fewer deaths from air pollution each year—although these benefits were mostly felt in highly developed countries.
In the absence of leadership from governments and large companies, researchers emphasized the importance of grassroots organizing, action from local governments and mass mobilization.
Global movements in recent years have pushed for governments and corporations to adopt renewable energy, end fossil fuel subsidies and stop building and insuring fossil fuel infrastructure. People in multiple countries have also advocated for climate reparations, rights of nature, return of land to Indigenous communities and the human right to a healthy environment, among other forms of climate justice action.
Some of these social movements have seen tangible wins, Dasandi said, pointing out a ruling by the top human rights court in Europe supporting a claim from more than 2,000 Swiss women who argued that their government’s climate policies had fallen short.
“We’re seeing examples of social movements … trying to push for this change, and actually having some positive effect,” Dasandi said.
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### Keerti Gopal
#### Reporter, Health and Justice
Keerti Gopal covers intersections between climate change, public health and environmental justice at Inside Climate News. Previously, she covered climate activism and movement repression. She is a National Geographic Explorer and has received fellowships from Fulbright, the Solutions Journalism Network, The Lever, and the National Press Foundation.
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