A recent study reveals a scary increase in hot and humid conditions during India's monsoon season. The rise in moist heat extremes, driven by global warming, has significant implications for labour productivity and the economy
In the period 1951-2020 the number of people in India facing extreme levels of humid heat during monsoons increased by at least 67 crore, research has found.
Recent research has examined the rise in hot and humid conditions, also known as 'moist heat extremes', typically experienced during summer monsoons, using the Wet-Bulb Globe Temperature (WBGT) measure.
A study conducted by researchers from Cornell University and others revealed that the area affected by severe and harmful wet-bulb temperatures surpassing 31 degrees Celsius has expanded by nearly 43 million square kilometres. This increase puts over 67 million people at risk.
"The consistent increase in exposed area (of close to 43 million square kilometres above 31 degrees Celsius can adversely impact the labour-intensive work during the monsoon break," the authors wrote in the study 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 monsoon season are a worrying threat to the health and well-being of the people of India, especially to physical labour, the researchers said.
Recent observations of extremes due to high humidity, primarily driven by global warming, have raised concerns. Exposure to such conditions in the long run can lead to potentially fatal health hazards, a serious issue that requires immediate attention, according to the authors.
For this comprehensive study, the researchers utilised data from the ERA5 dataset, which provides hourly estimates for temperature, humidity, and wind speeds. This robust methodology ensures the credibility and reliability of the findings.
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 percent and contribute to at least 4 percent reduction of GDP in India, which leads to inflation in crop prices," the authors wrote.
Therefore, with work performance projected to decline in the country by 30-40 percent by the end of the century, the rising moist heat during monsoon can be devastating in the future, they said. PTI KRS HIG