Younger people disproportionately represented in climate heat-related mortality trend according to Mexico study

Sorry Kids... latest research shows that increasing temperatures adding to extreme heat due to burning fossil fuels has a disproportionate impact in killing young people under 35 years. While this research is based on Mexico, it is highly likely it applies more widely, although there will be some caveats.

One of the authors of the study, Danny Bressler, said: "The concentration of heat-related mortality among younger people is quite disproportionate compared to other causes of death. Although just 16% of overall deaths from all causes are among under 35 year olds, 75% of heat-related deaths are among under 35 year olds. When we consider lost life years, the age-specific inequality is more extreme: 87% of heat-related lost life years occur among under-35-year-olds."

Meanwhile Australia's Environment Minister is set to approve another 3 coal mines pushing up the temperature and endangering our children's future.

Heat disproportionately kills young people: Evidence from wet-bulb temperature in Mexico (December 2024)

The Abstract makes for interesting reading:

Recent studies project that temperature-related mortality will be the largest source of damage from climate change, with particular concern for the elderly whom it is believed bear the largest heat-related mortality risk. We study heat and mortality in Mexico, a country that exhibits a unique combination of universal mortality microdata and among the most extreme levels of humid heat. Combining detailed measurements of wet-bulb temperature with age-specific mortality data, we find that younger people who are particularly vulnerable to heat: People under 35 years old account for 75% of recent heat-related deaths and 87% of heat-related lost life years, while those 50 and older account for 96% of cold-related deaths and 80% of cold-related lost life years. We develop high-resolution projections of humid heat and associated mortality and find that under the end-of-century SSP 3–7.0 emissions scenario, temperature-related deaths shift from older to younger people. Deaths among under-35-year-olds increase 32% while decreasing by 33% among other age groups.

A couple of other quotes from the study:

"Climate change is projected to cause more heat-related mortality and less cold-related mortality across all age groups. Cold-related mortality continues to be concentrated among individuals 35 and older—with the impact especially pronounced on individuals 70 or older—while heat-related mortality continues to be concentrated among individuals under 35 years old. However, as hot days become more frequent and cold days become less frequent, the overall temperature-related mortality burden shifts toward the young and away from the old. Older individuals continue to suffer disproportionately from cold-related mortality, but cold days are comparatively less frequent. Those under 35 suffer disproportionately from increasing heat, with premature mortality especially concentrated in the under-5 and 18 to 34 age groups."

"In all scenarios, climate change shifts the risk of temperature-related mortality toward those under 35 and away from those 50 and older. Under the SSP 3–7.0 emissions scenario, we project a 32% increase in temperature-related deaths among under-35-year-olds driven by an increase in heat-related mortality and a 33% decrease among those 35 and older driven by a decrease in cold-related mortality"

Fig. 2. Historical and projected annual temperature-related deaths in Mexico.

The panels show average annual temperature-related deaths resulting from exposure to days with the average wet-bulb temperatures shown on the x axis during the historical period (left) and at the end of the century (2083–2099) under the SSP 3–7.0 GHG emissions scenario (right) across six age groups in Mexico. The figure shows mean projected deaths; see Fig. 3 for projections with uncertainty.

Fig. 3. Historical and projected annual deaths due to heat and cold exposure by age group.

The figure depicts the average annual number of deaths attributed to heat (top) and cold (bottom) exposure in Mexico historically and under wet-bulb temperatures prevailing at the end of the century in four GHG emissions scenarios. Whiskers above and below each estimate depict 95% confidence intervals net of both econometric and climate uncertainty. Note that the range of the y axis in the bottom panel is roughly eight times the range of the y axis in the top panel.

One of the authors, Danny Bressler, explains in a thread on Bluesky :

"The concentration of heat-related mortality among younger people is quite disproportionate compared to other causes of death: 

"Although just 16% of overall deaths from all causes are among under 35 year olds, 75% of heat-related deaths are among under 35 year olds"

"When we consider lost life years, the age-specific inequality is more extreme: 87% of heat-related lost life years occur among under-35-year-olds."

"Cold-related deaths, on the other hand, are overwhelmingly concentrated among older individuals: 96% of cold-related deaths and 90% of cold-related lost life years are in individuals over 50.

"An important driver of these findings: while older individuals are the most vulnerable on an absolute basis to the most extreme record-breaking temperatures, e.g. daily average temps of 30°C wet bulb temperature (which is equivalent to 45°C/ 114°F & 30% humidity)...

"...younger individuals are much more vulnerable to hot days that occur more frequently. E.g., when daily avg. temp is 21°C wet bulb (equivalent to 34°C/93°F with 30% humidity), we see significantly elevated mortality for <35 year-olds, but no elevated mortality for 50+

"This has important implications for climate change. We project that the burden of temperature-related mortality will shift from older-age groups (more vulnerable to cold) to younger age-groups (more vulnerable to heat)."

"Across each of the four emissions scenarios we consider from very optimistic to very pessimistic, temp-related deaths increase for <35, as greater mortality from more heat exposure outweighs less mortality from less cold exposure for this age group that is comparatively more vulnerable to heat….

"…but a decrease in temperature-related deaths for >50 year olds, as less mortality from cold exposure outweigh more mortality from heat exposure for this age group that is comparatively more vulnerable to cold.

"In our discussion, we discuss potential mechanisms. We think that occupational exposure from working in manual labor (e.g. ag, construction) is a large part of the story here, and our preliminary not-yet-published findings suggest that this is the case."

Reference: 

This study was just published December 2024.

Andrew J. Wilson et al. ,Heat disproportionately kills young people: Evidence from wet-bulb temperature in Mexico.Sci. Adv.10,eadq3367(2024).DOI:10.1126/sciadv.adq3367

https://www.science.org/doi/10.1126/sciadv.adq3367