Does Climate Change Increase The Number of Deaths Due to Temperature Extremes?
Both cold and hot temperature extremes cause death. Which one is more deadly?
In my climate change post, I commented that “global warming is reducing the number of deaths due to temperature extremes. Several people disagreed with me and pointed to comments like this one from the WHO (World Health Organization):
“Climate change is the biggest global health threat of the 21st century…. 37% of heat-related deaths are attributed to climate change.”
Is that really true? Let’s look at the facts.
Deaths Due to Temperature Extremes
A number of studies have looked at this, including one in The Lancet that included 68 scientists from 33 countries.
Globally, cold deaths are 9 times higher than heat-related ones. In no region is this ratio less than 3, and in many, it’s over 10 times higher.
Cold is more deadly than heat, even in the hottest parts of the world.
Other studies have found similar results.
A study across 854 cities in Europe found that cold-related deaths were around ten times higher than heat-related ones.
A detailed study across England and Wales found that cold-related deaths were two orders of magnitude higher.
And the United States.
It is important to note that these deaths are mostly due to moderately cold conditions, not freezing temperatures. But it’s a robust and consistent result, accepted by most scientists. More people die from cold than heat.
Not Everyone Agrees
You might think that getting death data is a simple matter, but it’s not, because most death certificates do not indicate temperature as a cause. Experts disagree on how to interpret the data they do have to work with.
In the US, there are two major sources of information. NOAA considers heat to be the bigger killer, while the CDC considers cold to be the bigger killer.
The details of this are discussed in an article called “Which Kills More People: Extreme Heat or Extreme Cold?”
The net conclusion, based on several studies, is that the CDC conclusion is correct and cold is the bigger killer in the US.
How Does Future Global Warming Change the Number of Deaths?
It is quite obvious that global warming will reduce deaths due to cold conditions and increase them due to warm conditions. The exact amount of change depends very much on the degree of warming.
A regularly cited study by Qi Zhao and colleagues looked at temperature-related deaths from 2000 to 2019 and found that heat-related deaths increased, but the number of cold-related deaths decreased. In total, annual temperature-related deaths had fallen by around 650,000 per year.
Global warming is reducing deaths.
The distribution of deaths will not be equal. Countries in colder climates will see more benefit from warming, while countries in current hot zones will see less benefit from warming, and may actually see an increase in the number of deaths.
Blue areas in the above map show a decrease in deaths in the future, while red color indicates an increase in temperature-related deaths.
As the temperature rises, we will see a reduction in deaths up to a point. Eventually, the number of total deaths will start rising again as high temperatures are more common globally. It is estimated that this won’t happen until we have a 3 °C temperature increase, which is not expected until the end of the century.
Global Death Statistics
Total deaths: About 5 million deaths annually are linked to non-optimal temperatures.
Cold-related: Approximately 4.6 million deaths per year are due to cold.
Heat-related: Roughly 489,000 deaths per year are due to heat.
Deaths linked to temperature are often not officially recorded as the primary cause but are due to exacerbating existing conditions like cardiovascular or respiratory diseases.
While cold is more deadly everywhere, the magnitude of this difference can vary by region. For example, Asia has the highest absolute number of both cold and heat deaths, while Europe accounts for the largest proportion of global heat deaths.
Heat kills within a few days of high temperatures, while cold kills over months. Deaths due to heat are more obvious and more easily tied to a heat wave by the media, giving viewers the wrong information.
Every time there is a heatwave, climate alarmists voice their message that global warming is an existential problem and needs to be solved.
It is time we stop believing the fear mongers and go with reality!