Jeff Masters Weather Blog

Climate change likely killed tens of thousands of people in 2023 » Yale Climate Connections

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.”

A portrait of a smiling young boy with glasses and a baseball hat.A portrait of a smiling young boy with glasses and a baseball hat.
Carter Vigh (Photo credit: Courtesy of Amber Vigh)

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.

Read more: For unhoused people in America’s hottest large city, heat waves are a merciless killer

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.

Read: How Phoenix is preparing for its next brutally hot summer

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.”

Read more: Wildfire smoke getting into your home? Build a DIY Corsi-Rosenthal air filter.

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.”


The 2024 wildfire season is expected to be another doozy in North America. If you are worried, you might consider purchasing an air quality monitor and buying (or building) an air purifier.

Yale Climate Connections meteorologist Jeff Masters suggested these air quality monitors:

  • PurpleAir sensors — “Very widely used and have a good reputation,” he said.
  • Aeroqual — “[It] did a nice job measuring ozone,” he said.
  • Flatburn — Masters hasn’t used this low-cost device from MIT, but said it seemed promising.

For other options, you can check out the results of low-cost, air quality sensor evaluations conducted by the South Coast Air Quality Management District

Additionally, for any weather event, look out for neighbors who are young, old, have health conditions, or don’t have access to safe shelter. You can make a difference in your community by advocating for increased education outreach and social services from your local, state, and federal government.

We help millions of people understand climate change and what to do about it. Help us reach even more people like you.

Table: Death tolls of 2023 extreme weather events

This table features only the 2023 extreme events that were determined to be influenced by climate change in analyses by World Weather Attribution or Climate Central.

Event Dates Affected region Reported or estimated deaths

High heat and humidity in Southeast Asia

The last two weeks of April 2023

Bangladesh, India, Thailand, and Lao PDR

13 people died of heat stroke in Navi Mumbai, India after attending an awards ceremony

Mediterranean heat wave

April 26-28, 2023

Spain, Portugal, Morocco, and Algeria

A Dutch motorcycle racer died of heat stroke during a race in Morocco.

Pacific Northwest spring heat wave

May 13-15, 2023

Northwest U.S. and Western Canada

No data

Quebec wildfires

May and June 2023

Eastern Canada

There were 17 deaths directly linked to the fires.

Southwest heat wave

June 15-17, 2023

Texas and Mexico

Texas reported 334 heat deaths in 2023, but it’s unclear how many were from this event. Mexico reported that 112 people died from the heat between March and the end of June 2023.

West Asia drought

July 2020-June 2023

Syria, Iraq, and Iran

No data

Heat wave in the Western U.S.

July 1-3, 2023

California, Nevada, Arizona, Colorado, Utah

Two people died while hiking in National Parks in California and Arizona in early July 2023.

Clark County, Nevada reported that 16 people died of heat-related causes in July 2023.

Heat killed at least 645 people in Maricopa County, Arizona in 2023.

Global July heat wave

July 2023

Large areas of the U.S. and Mexico, Southern Europe, and China

Mexico reported 249 heat deaths throughout the summer of 2023.

In August 2023, experts estimated the summer would tally thousands of heat deaths in the U.S., according to Politico.

2023 data is not available for Europe, but over 70,000 people died of heat-related causes during the previous, cooler summer of 2022.

The heat killed at least two people in Beijing, China.

Heat wave in Florida and Puerto Rico

June 15-Aug. 8, 2023

Florida and Puerto Rico

Puerto Rico has only reported one official heat death since 2015. It was in 2017.

Two people died in the heat working on farms in Florida in 2023.

August heat wave in Europe

Aug. 22-25, 2023

Western and Central Europe

No data

South America heat wave

Aug.-Sept. 2023

Argentina, Brazil, Paraguay, and Bolivia

Four heat deaths were reported in Sao Paulo, Brazil. Even later in the year, in November, a fan at a Taylor Swift concert in Rio de Janeiro died due to heat-related causes.

Tropical Storm Daniel

Sept. 3-7, 2023

Bulgaria, Spain, Turkey, Greece, and Libya

Flooding killed at least four people in Bulgaria, six in Spain, seven in Turkey, and 17 in Greece.

The Libyan Red Cross reported over 11,300 deaths and over 10,000 people still missing in mid-September, 2023.

UK and Ireland heat wave

Sept. 6-8, 2023

United Kingdom and Ireland

No data

Flooding in the Horn of Africa

Oct.-Dec. 2023

The South of Ethiopia, Eastern Kenya, and many regions in southern and central Somalia

Flooding killed at least 90 people in Kenya, 99 people in Somalia, and 43 people in Ethiopia.

Madagascar heat

Oct. 2023


No data

Tropical storm Bettina

Nov. 25-27, 2023

Romania, Bulgaria, Moldova, Ukraine, Turkey, and Russia

At least 23 people were killed in the storm.

U.S. Midwest winter heat

Dec. 21-25, 2023

Minnesota, Wisconsin, and Iowa

No data was available. Because this event did not cause weather conditions that are extreme to humans, there are likely no associated deaths.

Source link