Indians Exposed To Extreme Humid Heat During Monsoon Rises By 67 Crore From 1951 To 2020
As a result, the health and well-being of those involved in physical labour could be affected, the researchers said.
Research indicates that the number of people in India exposed to extreme humid heat during monsoon season has risen by at least 67 crore from 1951 to 2020.
The study examined the trends in "moist heat extremes", which are prevalent during the summer-monsoon season, using the Wet-Bulb Globe Temperature metric.
Researchers, including a team from Cornell University in the US, have discovered that the area subjected to extreme and harmful wet-bulb temperatures exceeding 31 degrees Celsius has expanded by nearly 43 million square kilometres, thereby affecting more than 670 million people.
"The steady rise in areas exposed to temperatures above 31 degrees Celsius could negatively affect labour-intensive tasks during the monsoon break," the authors noted in their study, which was published in the journal Earth's Future.
They also found that the regions most vulnerable to moist heat extremes with wet-bulb temperatures higher than 38 degrees Celsius were primarily along the Indo-Gangetic plain and eastern coast.
"The increase in moist heat can directly impact about 37-46 million people living over the Indo-Gangetic plain," the authors wrote.
The humid and hot conditions during monsoons are a significant challenge to the health and well-being of the people of India, especially to physical labour, the researchers said.
Extremes due to high humidity have been observed in recent times, largely driven by global warming. Prolonged exposure to such conditions can result in potentially fatal health hazards, according to the authors.
For the study, the researchers used data, including those related to temperature, humidity and wind speeds, from the ERA5 dataset—the fifth generation of the European Centre for Medium-Range Weather Forecasts—which provides hourly estimates for these quantities.
They found that global warming has significantly increased days of hot-and-humid extremes to 10 between 1951 and 2020.
The researchers drew attention to the immediate need to revise outdoor working hours, especially in the regions experiencing extreme moist heat conditions during monsoon season, as humid heat can severely impact labour productivity.
"For instance, a 3 degrees Celsius increase in global warming can reduce labour productivity by 7% and contribute to at least 4% reduction of GDP in India, which leads to inflation in crop prices," the authors wrote.
Consequently, with an anticipated drop in work performance by 30–40% by the end of the century, the escalating moist heat during the monsoon season could have catastrophic effects in the future, according to the experts.
(With inputs from PTI)
