With thunderstorms and dust storms serially pounding Delhi-NCR and some other states this month, meteorologists tell Richa Sharma their increasing severity and frequency are causes for concern but there is a lack of research on such extreme weather events
May has been the cruellest month this year, what with the mercury kissing 45 degrees Celsius and above and a series of thunderstorms and dust storms with unprecedented wind speeds wreaking havoc in Delhi-NCR and in many other states. Two of the biggest storms struck on May 2 and May 13, killing over 230 people and raising serious concerns about the extreme weather events.
In the May 2 thunderstorm, the effects of which spilled over into the day after, nearly 134 people were killed in Uttar Pradesh and Rajasthan, mostly by uprooted trees and electric poles. At least 12,000 electric poles were wrenched out of the ground by gusty winds and some 2,500 transformers damaged. Likewise in the May 13 thunderstorm, where winds with speeds of over 100kmph struck the capital, some 80 people died across the country in states such as Uttar Pradesh, Delhi, Uttarakhand, Andhra Pradesh and West Bengal.
Although such weather events are not unusual for this time of the year, what is worrying is that the intensity and frequency of the storms have increased over the last three-four decades, say experts.
While only nine such storms were recorded in the March-May period between 1980 and 2003, there have been as many as 22 between 2003 and 2017, according to data from the Centre for Science and Environment. The jury is still out on whether these have any link with global warming and climatic changes.
According to the Fifth Assessment Report of the UN Intergovernmental Panel on Climate Change (IPCC), since the 1950s, there have been clear changes in many types of extreme events with more hot days and heat waves, fewer cold nights and an increase in the intensity and number of heavy rainfall days.
Speaking about the thunderstorms and dust storms that have struck India of late, scientists at the India Meteorological Department (IMD) said there was a lack of research on such weather events. Few studies have been done to analyse whether the increasing frequency and severity of dust storms and the unusually high temperatures in the last few years are linked to climate change, they said.
The National Weather Forecasting Centre (NWFC), which keeps tabs on the soaring mercury in summer, has recorded a rise in the severity of dust storms this year. Dr K Sathi Devi, the Head of NWFC, said, “I can’t say if it (dust storm) has increased or not this year, but the severity of dust storms is on the higher side and even its activity is more compared to last year... We can only give warnings and they were in place.”
Private weather forecaster Skymet Weather said dust storms were a pre-monsoon phenomena triggered by very high temperatures — at least over 40 degrees Celsius — and western disturbances.
“The frequency of dust storms has increased this year and there have not been such severe dust storms in the last seven-eight years. One unusual thing this year is active western disturbances, which generally ends by March, continuing till May. There is no particular reason why that happened,” said Mahesh Palawat, Vice-President, Meteorology and Climate Change, Skymet Weather.
The IMD has attributed the severe storms since the beginning of May to intense heating, pressure gradient and strong dust-laden winds. “From March-May, this activity prevails every year. Prevailing weather (meteorological) conditions were satisfactory for occurrence of this type of severe weather that created this activity over northwest India,” Devi said.Former IMD director-general L S Rathore said severe dust storms were not a new phenomenon and more severe dust storms had struck in the last few years.
“Dust storms and thunderstorms are part and parcel of the pre-monsoon season. In certain years, they happen on a larger scale, are more frequent and last for a longer period like this year,” said Rathore.
Devi said dust storm activity changed from season to season and it was not possible to forecast if similar conditions would prevail next year. “No study is readily available (in case of dust storms), like in monsoon, rainy days are decreasing but rain intensity is increasing,” she said.
A major concern that the storms have created is the high number of deaths. Rathore said the deaths have mainly been due to uprooting of trees, snapping of electric wires and the resultant electrocution, and the collapse of structures that could not withstand high wind speeds.
According to the Centre for Science and Environment (CSE), extreme weather events were expected to increase as temperatures rise globally.
“The enormity of losses due to dust storm is truly shocking. But the fact is dust storms will become more and more intense as the global temperature increases further. Climate change is intensifying extreme weather events,” said Chandra Bhushan, deputy director, CSE.Scientists at the NWFC are expected to analyse the impact of global warming on the severity of dust storms.
“There have not been many studies done by Indian scientists that link climate change with dust storms. It needs to be analysed with data over the years in the Indian context,” said Devi.Skymet’s Palawat said, “The IMD has data which need to be analysed to get a trend. Most of the studies now are related to the impact of climate change on cyclones, rainfall during monsoon and the rise in sea levels, among others,” he said.
