Worst drought, worse to come

The monsoon season leaves India not just with the worst drought in decades but a sombre forecast for future.

In terms of affected area, this year’s drought is the worst since 1918. Conditions surpass the one in 1972, considered the worst post-independence drought year.

The Indian Meteorological Department (IMD) reported deficient monsoon, with rain shortfall at 22%. Moreover, the area under deficient rainfall covers 56% of the country’s districts, the IMD said.

When there is more than 10% rainfall deficiency, and more than 20% of the area is under dry weather, it is an “all-India drought”. A “widespread drought” is when there is more than 10% deficiency, affecting more than 20% of the geographical area of the country. This year, there’s 20% rainfall deficiency which has affected more than 50% of the area.
In the past 123 years, there have been 25 years of widespread drought. In terms of spread, the one in 1918 was the most severe, affecting more than 70% of the area, followed by 1899 (68.4%), 1877 (59.4%), 1972 (52.6%) and 1987 (47.7%). In 2002, rainfall deficiency was 19%, and 29% of India was under drought.

Recent studies predict that rainfall will deteriorate in the coming years. The melting of glaciers in the Arctic circle seems too far away to cause concern to Indians, but according to BN Goswami, director of the Indian Institute of Tropical Meteorology (IITM), Pune, freshwater melting from Greenland’s ice sheet could weaken the monsoon to the extent of threatening perpetual drought. The Greenland ice melt will add more freshwater to the north Atlantic Ocean, making it less saline. This could weaken the circulation of ocean waters and temperature variations over the Indian subcontinent — two key factors that could also weaken the summer monsoon, says Goswami.

Another study recently published in Nature said global warming may increase the frequency of a new breed of El Nino weather events, called El Nino Modoki, which would lead to rise in the frequency and intensity of droughts in India.

A study by Centre for Atmospheric Research at Indian Institute of Technology Delhi in May says the monsoon is weakening. Researchers found that long rainy spells — more than 2.5 millimetres of rain daily for more than four consecutive days — decreased across the country over the last 50 years while short and dry spells — less than 2.5 mm rain daily increased.

In March, an article in Down to Earth magazine said while parts of the country are receiving extreme rainfall, overall moderate rainfall that benefit crops, is decreasing. Another study in Current Science said the number of days of more than 12 mm rainfall have decreased by 78% in the past 53 years.

In March, a Purdue University found that climate change could influence monsoon dynamics and cause less summer precipitation, a delay in the start of monsoon season and longer breaks between rainy periods. The South Asian summer monsoon — critical to agriculture in Bangladesh, India, Nepal and Pakistan — could be weakened and delayed due to rising temperatures, it said.