Key Takeaways:

• Extreme heat is often identified as the most significant cause of premature death attributed to climate change.
• Peer reviewed research, informed by real-world data, clearly shows deaths associated with cold temperatures significantly outnumber heat related deaths by almost 10 to 1.
• The same research shows that deaths associated with extreme temperatures have declined significantly during the recent period of modest warming.

Short Summary:

A 2021 study published in the prestigious medical journal The Lancet reported that cold temperatures contribute to far more deaths each year than warmer temperatures and that temperature related deaths are declining globally.¹

The study reports that the number of deaths associated with cold temperatures decreased by more than double the amount that deaths tied to hotter temperatures increased over the 20 year period of the study.

The study is arguably the largest of its kind studying the issue of the temperature related deaths. Sixty-eight scientists representing universities and research institutes in 33 countries spanning all regions of the world contributed to the study. Their research found that as the earth has modestly warmed, deaths caused by “non-optimal” hot and cold temperatures have declined dramatically. As a percentage of overall deaths annually, almost 600,000 people die globally from heat, compared to 4.5 million from cold.

Monash University’s press release announcing the study stated, “[i]mportantly, cold-related death decreased 0.51 per cent from 2000 to 2019, while heat-related death increased 0.21 per cent, leading to a reduction in net mortality due to cold and hot temperatures.”² (See Figure 1, below)

 

Another critical finding of The Lancet study is thatcold related deaths outnumber heat related deaths 10 to 1. (See the table below)

COLD RELATED DEATHS BY REGION	HEAT RELATED DEATHS BY REGION
Africa 1.18 million	Africa 25,550
Asia 2.4 million	Asia 224,000
Europe 657,000	Europe 178,700
South America 116,000	South America 25,250
UK 44,600	UK 8000
US 154,800	US 18,750
China 967,000	China 71,300
India 655,400	India 83,700
Australia 14,200	Australia 2300
Total: 6,189,000	Total: 637,550

In part as a result the decline in cold temperatures, over the period of the study, temperature-related mortality has declined significantly, with a total of 166,000 fewer deaths tied to non-optimal temperatures.

This study confirms what research previously published in The Lancet, the Southern Medical Journal, and the Centers for Disease Control, and National Health Statistics Reports has consistently shown: Cold is the biggest temperature related killer, not heat.^4,5,6

These studies also indicate the slight warming we’ve seen over the past century has reduced overall mortality related to extreme temperatures. This positive trend should continue if the earth continues to warm modestly.

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References:

1. Global, regional, and national burden of mortality associated with non-optimal ambient temperatures from 2000 to 2019: a three-stage modelling study, Qi Zhao, et al., The Lancet Planetary Health, July 2021, accessed October 7, 2022, https://doi.org/10.1016/S2542-5196(21)00081-4.
2. 5 million deaths a year caused by global climate related abnormal temps. Monash University, EurekAlert, July 7, 2012, accessed October 7, 2022, https://www.eurekalert.org/news-releases/580418.
3. The heresy of heat and cold deaths, Bjorn Lomborg, July 2021, accessed October 10, 2022, https://www.lomborg.com/the-heresy-of-heat-and-cold-deaths
4. Mortality risk attributable to high and low ambient temperature: a multicountry observational study, Gasparrini et al., The Lancet, May 21, 2015, accessed October 11, 2022, https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(14)62114-0.pdf
5. The impact of global warming on health and mortality, National Library of Medicine, Southern Medical Journal, accessed October 11, 2022, https://pubmed.ncbi.nlm.nih.gov/15586600/
6. Deaths Attributed to Heat, Cold, and Other Weather Events in the United States, 2006–2010, Berko et al., United States Center for Disease Control, National Health Statistics Reports, July 30, 2014, accessed October 11, 2022, https://www.cdc.gov/nchs/data/nhsr/nhsr076.pdf