As heat and humidity levels rise throughout the day because of climate change, Bangladesh loses around 254 hours of labour/person/year due to extreme heat exposure, a new study led by Duke University researchers found recently.
The study, titled, "Increased labour losses and decreased adaptation potential in a warmer world", said that economic losses associated with this lost productivity globally could reach up to $1.6 trillion annually if warming exceeds an additional 2°C compared to the present, said a press release.
Workers in Asia, the Middle East, and Africa will bear the worst impacts, the study projected.
Bangladesh could lose approximately 21 billion working hours if global temperature rises by 1°C, compared to the 7 billion losses at the current temperature, the Duke University researchers found.
If the temperature rises by 1°C, the global average labour loss will reach 134 hours/person/year, while Bangladesh alone will lose 391 hours/person/year.
According to the study, it is alarming that Bangladesh may lose around 573 hours of labour/person/year if the global temperature rises by 2°C.
Heat-related labour productivity losses can be as high as 280 to 311 billion dollars per year.
Most of these losses occur in low-and middle-income countries such as Bangladesh, which are heavy in manual labour like agriculture and construction.
Bangladesh can save around 30 minutes of productivity loss even if temperature changes by 4°C.
However, as heat exposure in the morning hours increases in the tropics and subtropics, this adaptation mechanism may become less effective eventually.
"Sadly, many countries and people most impacted by current and future labour losses are not responsible for the bulk of greenhouse gas emissions," said Luke Parsons, a climate researcher at Duke University's Nicholas School of the Environment, who led the study.
"However, about 30% of this lost labour can still be recovered by moving it to the early morning. But with each additional degree of global warming, workers' ability to adapt this way will swiftly decrease as even the coolest hours of the day quickly become too hot for continuous outdoor labour," he added.
Parsons and his colleagues published their new peer-reviewed paper on 14 December in Nature Communications.
They project future labour losses for every country worldwide under a global temperature rise of 1°C, 2°C, 3°C, and 4°C relative to the present.
The study added that labour losses due to heat exposure are caused by a combination of large working-age populations, seasonal heat exposure, and large proportions of the people employed in agriculture and construction.
Furthermore, a temperature rise by 2°C or 4°C can result in a loss of 31 or 57 billion work hours annually in the country.
Bangladesh, after India and China, is the second most vulnerable country in Southeast Asia to labour harm as a result of prolonged exposure to rising temperatures, the study found.
To develop this study, the scientists used a blend of observation-based meteorological data and climate model projections of temperature and humidity to estimate humid heat exposure, current labour losses, and projected future labour losses under additional warming.