Climate change is making Japanese summers hotter and more humid, driving annual losses in working hours due to reduced productivity to 2.9 billion hours. Midsummer temperatures and humidity in Tokyo have already approached levels seen in Bangkok and Singapore, analysts say.
According to the Nikkei newspaper on Saturday, an analysis of climate data from major cities worldwide from 2020 through last year — drawing on figures from the US National Oceanic and Atmospheric Administration — found that Tokyo's peak temperatures and humidity in July and August were comparable to those of Bangkok and Singapore. The findings point to a clear "tropicalization" trend, with both temperature and humidity rising compared with the 2000s and 2010s.
Extreme heat and high humidity impair the body's ability to regulate temperature, sharply reducing work efficiency. An analysis by the British medical journal The Lancet, based on labor intensity by industry and employment figures, estimated that Japanese workers lost an average of 43 hours per person last year — equivalent to more than five eight-hour workdays.
Extrapolated across Japan's entire workforce, the total annual loss comes to approximately 2.89 billion hours. That is more than double the annual average of roughly 1.4 billion hours recorded in the 2010s.
The problem extends well beyond Japan. In China, where agriculture and construction account for a large share of employment, workers lost an average of 96 hours per person last year — more than twice Japan's figure. The Lancet estimates that heat-related productivity losses could cost the global economy around $1 trillion annually.
Governments are tightening restrictions on working hours and safety regulations during extreme heat. Japan revised its industrial safety and health rules last year, making it mandatory for employers to establish reporting systems and emergency response procedures at workplaces at risk of heatstroke.
Yet the toll from extreme heat continues to grow. According to Japan's Ministry of Health, Labour and Welfare, heatstroke casualties at industrial sites reached 1,681 last year — a 40 percent increase from the previous year and the highest figure since the ministry began tracking the data in 2005.
attom@heraldcorp.com
