Climate Change Turns Japanese Summers Tropical, Causing 2.9 Billion Hours of Lost Labor

Climate change has made Japanese summers hotter and more humid than in the past, resulting in an annual loss of approximately 2.9 billion labor hours, according to a recent study.
On July 5, the Nikkei reported that an analysis of global city climates from 2020 to last year, based on data from the U.S. National Oceanic and Atmospheric Administration (NOAA), showed that the maximum temperatures and humidity levels in Tokyo during July and August were comparable to those in Bangkok, Thailand, or Singapore.
The newspaper noted that both temperature and humidity in Tokyo during July and August have risen compared to the 2000s and 2010s, with the phenomenon of "tropicalization" becoming clearly evident.
In hot and humid weather, the body's thermoregulation function struggles to operate, and consequently, the cost of climate change can lead to a decline in productivity.
According to estimates by the British medical journal The Lancet, which calculated labor efficiency losses due to heat based on labor intensity by industry and the number of employed persons, Japan saw an estimated loss of 43 labor hours per person in 2024.
Assuming an 8-hour workday, this exceeds five days of work, and when applied to the entire Japanese workforce, it amounts to 2.89082 billion hours.
This is a twofold increase compared to the 2010s, when the average annual loss of labor hours was 1.42771 billion.
It is not just Japan; other countries are also experiencing significant labor losses due to extreme heat.
In China, which has a large number of workers in agriculture and construction, the annual labor hour loss per person in 2024 was 96 hours, double that of Japan, and the potential global economic loss due to heatwaves was estimated at 1 trillion dollars.
As countries rush to implement measures such as establishing work restriction rules during heatwaves, Japan also revised its Ordinance on Industrial Safety and Health last year. The revision mandates that employers establish reporting systems and emergency response procedures for work involving risks of heatstroke and ensure these are widely communicated to workers.
However, according to Japan's Ministry of Health, Labour and Welfare, the number of heatstroke casualties in industrial workplaces last year reached 1,681, a 40 percent increase from the previous year and the highest on record since statistics began in 2005.
(Photo: AP, Yonhap News)
※ Please note: This article was translated by AI and may contain errors.