Climate change played a role in killing tens of thousands of people in 2023

At nine years old, Carter Vigh loved soccer, his friends, and dancing to music.

“He was just the kid that everybody wanted to hang out with, and he was always willing to make the time for anybody and willing to stand up for anyone that was being bullied or sad,” said Carter’s mom, Amber Vigh. “He was tiny but mighty.”

Carter also had asthma. The hot temperatures and dense wildfire smoke that enveloped the Vighs’ British Columbia home, 100 Mile House, in the summer of 2023 exacerbated his asthma and killed him.

Carter’s family did everything they knew how to do. They kept Carter inside on smoky days. They made sure he always had his inhaler. On the morning of his last day, they checked air quality measurements before taking him to summer camp. But they’d later learn that the air quality data they’d reviewed was coming from a sensor nearly 100 kilometers (62 miles) away from their home.

“The day that Carter died, if you had asked me up until about 4 o’clock that night, ‘How’s Carter?’ I would have told you he was great,” Vigh said.

Climate change likely played a role in Carter’s death. In a 2023 study, researchers found that recent extreme wildfire seasons in British Columbia were correlated with hot summers and high levels of evaporation. “It is likely that the potential for wildfire will continue to increase in the upcoming century, even under the most optimistic climate scenario,” the study’s authors wrote.

Carter was one of tens of thousands of people whose lives were cut short in extreme weather events in 2023. As climate change intensifies extreme weather, more deaths can be expected. But many lives can still be saved. Carter’s family has partnered with the BC Lung Foundation to improve education and install air pollution monitors across British Columbia.

“People need to realize how insane our climate has become and how dangerous it can be for people that have lung issues,” Vigh said.

How many people did climate change kill in 2023?

It’s impossible to accurately calculate the number of people who died in 2023 as a result of climate change. But a review of data suggests that, at minimum, tens of thousands of people died in climate-change-influenced weather events around the world last year.

​​Deaths reported from extreme weather events like heat waves are almost always undercounts. For example, death certificates often list only causes of death such as heart failure, even if hot temperatures played a role.

Kristie Ebi studies the health risks of climate change at the University of Washington. Ebi said more accurate numbers can be generated by looking at excess deaths, a measure that compares the total number of deaths to the average number under normal circumstances. “You get these numbers of ‘X number of people died in a heat wave,’ and then you go and look at the number of excess deaths, and it’s like, no, that’s not really the case,” she said.

A field called attribution science can also be used to understand how climate change is contributing to extreme events, including those that hurt or kill people. The field aims to quantify how much the burning of fossil fuels supercharged a given heat wave, hurricane, wildfire, drought, flood, or other extreme weather event.

World Weather Attribution and Climate Central are leaders in producing and communicating climate attribution science. Combined, the two organizations analyzed 19 different weather events of 2023 to see whether the fingerprint of climate change was present. For 17 of those events, the answer was a clear yes. For the remaining two, limited data and high uncertainty meant the researchers couldn’t quantify the effect of climate change.

For six of those events, no official mortality data is available. Those events include an early heat wave in the Pacific Northwest and Western Canada that had high temperatures made five times more likely by climate change and a drought in Syria, Iraq, and Iran that would have been so much less severe without climate change that it wouldn’t have been classified as a drought at all.

Comprehensive data were also not yet available for 2023 heat waves in Europe, though French authorities reported that three out of every 100 deaths in the summer of 2023 resulted from heat. And a study of the 2022 European heat wave estimated that 70,066 people died. Temperatures in the summer of 2023 were even higher than the previous year.

And even events with official mortality data likely underestimate the true death toll. For a detailed look at the events analyzed by World Weather Attribution and Climate Central and their associated death tolls, see the table at the end of this article.

What can be done to stop the dying?

The World Health Organization expects the globe will see 250,000 deaths annually as a result of climate change by 2030, an estimate it says is conservative.

Many of the deaths associated with extreme weather and climate change in 2023 could have been prevented — with better infrastructure, stronger outdoor worker protections, and improved access to cool, safe shelter. Ebi from the University of Washington said that the No. 1 thing she would like to see all local governments do is to develop a heat wave early warning and response plan.

For Amber Vigh, there are two big things she wishes she had known. The first is that indoor air isn’t automatically safe. Open or poorly sealed windows and doors, in addition to gas and wood-burning stoves, can lead to indoor air pollution.

“You need to have your air purifiers, and you need to keep an eye on the air quality in the house as well,” Vigh said.

Vigh also wishes she’d known how much the air quality can vary from one town to another.

“Carter’s parents, they knew that he was asthmatic and knew he was prone to these types of exacerbations,” said Chris Lam, president and CEO of the BC Lung Foundation. “They did all the right things. They knew all the right things to do. The one thing they did not have was accurate air quality information.”

To help prevent future deaths, the Vighs partnered with the BC Lung Foundation to create Carter’s Project, which with the help of donations aims to distribute PurpleAir monitors across British Columbia. The project will also increase access to the foundations’ asthma camps, which help families understand how to keep kids with asthma safe.

Thanks to Carter’s Project, 100 Mile House will have an air monitor network in place in May, before the 2024 wildfire season takes off. Vigh is extremely proud of this, but it’s also heartbreaking for her.

“It’s hard because if this had been done five years ago, two years ago, my son could still be here,” she said. “I just hate that it had to be my kid.”