Study links climate crisis to low rainfall
MONSOON PATTERN ‘Significant decreasing trends’ found in the south-west monsoon from 1989 to 2018 in the Ganga basin states
NEWDELHI: Parts of India are facing a severe impact of the climate crisis with reduced rainfall and increase in dry, or no rain, and heavy rain days during the monsoon season, an India Meteorological Department (IMD) study on changes in monsoon patterns over 30 years has found.
The monsoon, which generally begins in June and retreats by September, delivers around 70% of India’s annual rainfall. It is crucial for the cultivation of rice, wheat, sugarcane and oilseeds in the country where farming employs over half of its people. The monsoon is key to replenishing reservoirs, groundwater and addressing water shortages.
The study found “significant decreasing trends” in the southwest monsoon from 1989 to 2018 in the Ganga basin states like Uttar Pradesh, Bihar and West Bengal, which are known to have among the most fertile lands in the country. Meghalaya, where Cherrapunji is known as one of the places with the highest precipitation globally, Nagaland and Arunachal Pradesh recorded a decreasing trend along with Himachal Pradesh.
The study found a significant increase in heavy rainfall (6.5 cm or more) days in Gujarat’s Saurashtra and arid regions of Kutch and south-eastern Rajasthan, as well as northern Tamil Nadu, northern Andhra Pradesh, south-west Odisha, parts of Chhattisgarh, south-west Madhya Pradesh, parts of West Bengal, Manipur and Mizoram, Konkan, Goa and Uttarakhand.
Goa has recorded the maximum monsoon rainfall over the past 30 years (2878.0 mm) followed by Meghalaya (2702.4 mm). Tamil Nadu reported the lowest (311.7 mm) followed by Rajasthan (414.2 mm). Pulak Guhathakurta, who heads the IMD’S hydrometeorology wing in Pune, said a Parliamentary standing committee had asked for a report on the impact of the climate crisis on monsoon in the recent decades. “The ministry of earth sciences presented this analysis to the Committee in February but it is being made public today [??],” said Guhathakurta, who has also conducted long-term studies on monsoon patterns with 100-year data.
He said there is multi-decadal variability. “For example, 1940 to 1970 was a wet period for us and now we are in a dry period. But there is a clear imprint of climate change on monsoon which is something that farmers have been trying to deal with. The Ganga basin is recording a significant increase in dry days.”
The IMD has put out individual detailed reports for states on variability in monsoon.
In a press statement on Monday, IMD (Pune) said the monsoon rainfall shows high temporal and spatial variability. “Further, in view of ongoing climate changes, there have been significant changes in the mean rainfall pattern and their variability exclusively in terms of the intensity and frequencies of heavy rainfall events.”