The Death Toll From Extreme Weather Is Becoming Clearer

In 2020, in the wake of Australia’s Black Summer bushfires, Paddy Manning wrote Body Count: How Climate Change is Killing Us (Simon & Schuster, 2020). He spoke with the families and friends of victims of extreme weather events and told the human stories behind the statistics. In this Next Chapter, Manning looks at why the death toll attributed to climate change continues to be systemically underreported as well as the consequences of that disconnect.

From wildfires to tornados, heat waves to hurricanes, there seems barely time to process the last climate disaster before the next one is upon us. The World Meteorological Organization estimates there were 151 unprecedented extreme weather events last year alone. The US Federal Emergency Management Agency responded to a major weather-related disaster on average every four days in 2024.

Heat waves, wildfires, floods, tropical storms and hurricanes are all increasing in scale, frequency and intensity, and the World Health Organization forecasts that climate change will cause 250,000 additional deaths each year by the end of this decade from undernutrition, malaria, diarrhea and heat stress alone. Even so, the impact on human health and the body count attributed to extreme weather remain massively underreported — resulting in a damaging feedback loop of policy inaction. Meanwhile, the very people who might fix that problem, at least in the US, are being fired en masse amid the Trump administration’s war on science.

To understand the death disconnect, consider the wildfires that tore through Los Angeles in January, destroying more than 16,000 buildings and killing 29 people. Within days, research group World Weather Attribution calculated the blazes were made 35% more likely by climate change. By early February, scientists were in the burn zone measuring pollutants that can pass into the lungs, bloodstream and brain when inhaled or ingested. They know the smoke will cause more deaths than the flames did, but it will take years to fully measure those long-term health impacts.

Those 29 fatalities “are the most obvious casualties of the actual event,” said Jonathan Patz, a University of Wisconsin-Madison professor who researches the health effects of climate change. “But the health impact is far broader in geography and also over time,” he said, highlighting the dangers of wildfire smoke to children’s respiratory health and to pregnant women and their unborn babies.

That was certainly true in Australia, which endured one of its worst-ever bushfire seasons in 2019-2020, known as the Black Summer. Thirty-three people died from the flames; within months, scientists estimated an additional 429 premature deaths due to smoke that circled the planet and was so thick at times that Sydney and Canberra had the worst air quality in the world. The total death toll after factoring in long-term impacts will likely be much higher.

Separate research from a team at Melbourne’s Monash University — experts at modeling health risks from wildfire smoke — made the cover of the prestigious Nature magazine in 2023. They found that air pollution from increasingly severe and frequent wildfires threatened billions of people, especially in low-income countries.

A member of that team, Yuming Guo, is now working on a first-of-its-kind study of the net health impact of a large set of environmental factors related to global warming — including heat waves, wildfires, wildfire smoke, floods, tropical cyclones and disease. It will be finished in the next six to 12 months.

The study will make projections from 2030 to 2100 under scenarios known as shared socioeconomic pathways, which model population, economic growth and greenhouse gas emissions. It will forecast outcomes at varying levels of global warming: temperature increases of 3C, 4C or 5C by the end of the century. Any of those increases would have significant impacts on the planet, but the difference in the number of projected net deaths is what might be described as the world’s body count from climate inaction.

Guo said he can’t talk about specific figures yet, as the Monash study is unpublished. But he has no doubt that the net number of annual deaths caused by climate change from 2030 will be much higher than the 250,000 forecast by the WHO. The main message from the research, he said, is that “if we make a great effort to mitigate climate change, many deaths will be prevented or avoided.”

Even once Guo’s all-cause analysis is complete, it will still be an undercount because the data doesn’t include likely deaths triggered by climate-driven food and water insecurity. It also won’t reflect deaths from conflicts. Sherri Goodman, the Pentagon’s first chief environmental officer, regards climate change as the “greatest security threat in global history.”

There are some systemic issues Guo’s study can’t account for. Deaths from hyperthermia, for example, have long been underrepresented because physicians often neglect to measure victims’ elevated body temperature before they die. As a result they typically record stroke or cardiac arrest as the cause of death. A warming planet also means that deaths from overheating will be partially offset by reduced deaths from cold exposure, or hypothermia, a factor Guo’s study will take into account.

However imperfect, a more accurate death toll could help refocus a debate that sometimes gets lost in environmental abstractions — ambient temperatures, atmospheric CO2 concentrations, sea levels, biodiversity loss — and ignores human beings.

A large portion of the public remains blithely unaware that climate change is a health hazard. Predictably, climate plummets down the everyday priority list, as overarching issues such as war or the spiraling cost of living come to seem more pressing. In the wake of Australia’s Black Summer, public concern about climate change was quickly overtaken by the Covid-19 pandemic.

But even equipped with better data, the challenge of moving the policy needle remains enormous, particularly as US President Donald Trump takes a wrecking ball to the scientific and medical community. The impact will be felt globally: The US has cumulatively emitted more greenhouse gases than any other country since the Industrial Revolution and currently contributes about 14% of global CO2 emissions, the biggest footprint after China. It is also a major contributor to climate science.

Emblematic of the administration’s blanket dismissal of what it regards as climate alarmism, Energy Secretary Chris Wright last month told an audience of oil and gas executives that climate change was a “side effect of building the modern world.” Trump’s top environmental regulator Lee Zeldin has ordered the Environmental Protection Agency to reconsider its landmark 2009 finding that greenhouse gases are a danger to public health, describing his action as “driving a dagger straight into the heart of the climate change religion.” And US Secretary of Health and Human Services Robert F. Kennedy Jr. is cutting 10,000 workers across the panoply of agencies within his department.

One of those, a unit of fewer than a dozen people called the Office of Climate Change and Health Equity, was shuttered as part of Trump’s crackdown on diversity, equity and inclusion. The office was set up under Biden in 2021 to be a central point of coordination on the health implications of climate change, including ways to protect Americans at greatest risk from extreme weather events. It pioneered data resources like the US’s first seasonal health forecast, and the first heat tracker — a real-time, geospatial index of emergency calls for heat-related injury around the country.

John Balbus retired as OCCHE director after his profile was included on a website called the “DEI Watchlist” — run by a conservative organization to identify federal workers who are allegedly hostile to Trump’s agenda. “We are losing ground in the effort to contain climate change, and having reliable estimates of how much it is already harming people is essential,” Balbus said in an interview. “The massive firings, reorganizations and cutting of research grants going on now under the Trump administration are crippling the nation’s science, preparedness and public health operations and undermining the nation’s ability to protect people from disease outbreaks and climate-related disasters, now and in the future.”

The cuts will inevitably mean less research into the health impacts of climate change, said Lisa Patel, executive director of the Medical Society Consortium on Climate and Health. “The effects of climate change are multiplying so rapidly,” she said. “This is the time when we need that research to be able to quantify the risks and take the appropriate precautions to keep people safe.”

Governments all over the world are scrambling to adapt to climate change — none more so than in Europe, the fastest-warming continent. More than 70,000 excess deaths occurred in heat waves there in 2003. Last August, the WHO said that heat-related mortality in Europe had increased 30% over the past two decades — to more than 175,000 deaths each year — and warned that it’s “set to soar.”

Scientists estimate roughly a third of heat-related deaths can be attributed to global warming, with the risk most pronounced in Europe, Southeast Asia and the Latin American Pacific coast.

For communities affected by climate disasters, the path to recovery is slow and uncertain. Barbara Sattler, a professor of nursing at the University of San Francisco and co-founder of the Alliance of Nurses for Healthy Environments, has been evacuated from Sonoma County three times because of wildfires and twice due to floods. She’s worried about the toxic fallout from the LA fires, particularly from smoke laden with chemicals after businesses such as dry cleaners, pharmacies and beauty salons went up in flames.

“Smoke does not go to heaven; smoke goes somewhere. It’s particulate matter. It lands on our fields, where it can be taken up in the soil. And it lands in our cities and our town,” Sattler said. “There are going to be increased rates of cancers, there are going to be a number of people who are probably going to commit suicide as a function of the unrelenting mental distress. But these are things that we don’t necessarily talk about, and the press is gone already.”

Sattler has campaigned for more than two decades to raise awareness of the health impacts of climate change. She said she once met an obstetrician who had delivered her own niece during the 2018 fire that leveled the Californian town of Paradise and killed 86 people. “She said, ‘I helped deliver my niece, whose first breath was the smoke of the Paradise fire,’” Sattler recounted, wondering aloud: “How many first breaths” like are we going to allow because we’re not “rapidly moving toward fixing the problem?”

Paddy Manning is an investigative journalist who has worked for the Australian Broadcasting Corp., Crikey, Fairfax and News Corp. He is the author of six books.