Climate change continues to have an increasingly worse effect on health and mortality around the world, according to a report published this Tuesday (14) that included the participation of an international team of 114 researchers.
One of the most alarming findings is that heat-related deaths of people over 65 have increased by 85% since the 1990s, according to a model that incorporates both temperature and demographic changes. People in this age group, along with babies, are especially vulnerable to health risks such as heatstroke. As global temperatures have risen, elderly people and babies are now exposed to twice as many heat wave days annually compared to the period from 1986 to 2005.
The report, published in the medical journal The Lancet, also tracked estimated income loss and food insecurity. Globally, exposure to extreme heat and the resulting losses in productivity or inability to work could have led to income losses of up to $863 billion by 2022. And in 2021, an estimated 127 million more people will have experienced moderate or severe food insecurity related to heat waves and droughts, compared to the period 1981 to 2010.
“We have lost very precious years of climate action and this has come at a huge cost to health,” said Marina Romanello, a researcher at University College London (UK) and executive director of the report, known as The Lancet Countdown. “The loss of life, the impact that people experience, is irreversible.”
The public health indicators tracked in the report generally declined over the nine years that researchers produced edits of the assessment.
The analysis also examined health outcomes for individual countries, including the United States. Heat-related deaths of adults over the age of 65 increased 88% from 2018 to 2022, compared to 2000 to 2004. An estimated 23,200 older Americans will have died in 2022 due to exposure to extreme heat.
“These numbers remind me of the elderly patients I see in my own hospital with heatstroke,” said Renee Salas, an emergency medicine physician at Massachusetts General Hospital and Harvard Medical School. She is one of the report’s co-authors.
The study’s data could help fill a gap for federal policymakers.
“We have a limited set of indicators for climate change and health that are routinely collected in the United States,” said John Balbus, director of the office of climate change and health equity at the U.S. Department of Health and Human Services. He did not contribute to the report and is not currently involved with The Lancet Countdown, but has previously served as a scientific advisor to the project’s funder.
Balbus cautioned that the study primarily measures people’s exposure to climate-related risks rather than actual health outcomes such as disease rates. To get to real health outcomes from exposures, he said more investment in research is needed.
For the first time, this year’s Lancet Countdown included projections for the future. If the global average temperature increases by 2°C compared to pre-industrial temperatures, an increasingly likely scenario unless society significantly reduces greenhouse gas emissions, the number of heat-related deaths will increase by 370% by mid-century, the report found.
At the same time, researchers highlight that reducing pollution from fossil fuels is proving beneficial to global health. Deaths from fossil fuel-related air pollution have decreased by 15% since 2005, with most of this improvement the result of a reduction in coal-related pollution entering the atmosphere.
The value of the Lancet Countdown is in its continuous monitoring of the effects of climate change on global health, said Sharon Friel, director of the Planetary Health Equity Hothouse at the Australian National University.
Friel was not involved in the report, but wrote a commentary accompanying the text.
Howard Frumkin, former special assistant to the director for climate change and health at the U.S. Centers for Disease Control and Prevention, said the report is important, but the climate impacts he is most concerned about are not highlighted in the text. Researchers and policymakers need to pay attention to the health effects of people displaced by climate change and migration, Frumkin said.
“If you’re on chemotherapy for cancer or if you’re on kidney dialysis or if you’re receiving treatment for addiction and you have to move suddenly, that’s terribly disruptive and threatening,” he said. Frumkin was not involved in the new report but co-authored previous editions.
Over the years, health experts involved in this project have included more research into the continued use of fossil fuels as the root cause of health problems. “The diagnosis in this report is very clear,” Salas said. “Further expansion of fossil fuels is reckless and the data clearly shows that it threatens the health and well-being of every person.”
The researchers highlight that healthcare systems and other social infrastructures on which health depends have not adapted quickly enough to our current level of global warming.
“If we weren’t able to deal with it today, chances are we won’t be able to deal with it in the future,” Romanello said.
The report will likely be discussed at COP 28, the UN’s annual meeting on climate change, which takes place in a few weeks in the United Arab Emirates.