The deluge that swept Mumbai this week is part of an ominous trend of extreme weather events including short bursts of devastating rain after a dry patch — phenomena whose frequency is rising because of climate change, scientists say.
India is seeing more extreme weather, with the past decade being the warmest and driest ever, which includes the very rare instance of successive droughts in 2014 and 2015, but this period has also seen several instances of short bursts of torrential rain which flooded Mumbai in 2005, Uttarakhand in 2013, Kashmir in 2014 and Kerala in 2018.
This year, the southwest monsoon began late in Mumbai, leaving it relatively dry for a month, but the rainfall city received within the span of two days was what it normally gets in the entire month of June. “Due to global warming, frequency of rainfall as well as temperature extremes are increasing, and will go on increasing in the future,” said SK Dash, former head of the Centre for Atmospheric Sciences, IIT Delhi, adding that scientific models are required to assess the relationship between climate change and a particular weather incident.
Global warming triggers intense bursts of rainfall because higher temperature increases the moisture-holding capacity of the atmosphere.
The Intergovernmental Panel on Climate Change (IPCC), a UN body had earlier noted that both droughts and floods were expected to increase in the subcontinent. This is particularly bad for farmers as they suffer from dry patches as well as floods, while statistically the rainfall may appear close to normal over a period that includes both extremes like in parts of Maharashtra in recent weeks.
‘Need to be Ready for Such Conditions’
Dash said Mumbai has been vulnerable because it is located on the coast, but on the whole, the country must be ready to face such extreme phenomena.
“There should be preparedness in the future because these incidents are only going to get more frequent,” Dash said.
Official weather data suggests that India has become much hotter in recent years. According to the India Meteorological Department (IMD), 2018 was the sixth warmest year in India since the weather office started maintaining records in the beginning of the last century. “It may be mentioned that 11out of 15 warmest years were during 2004-2018. Past decade (2001-2010/2009-2018) was also the warmest decade on record,” IMD had observed.
In the cast of Mumbai, heavy rainfall is common, said M Mohapatra, IMD’s director general of meteorology. “Every year during July and August, we get heavy rainfall at least two to three times. Last year, it was during August. In 2005, it was on July 26. It’s natural. Mumbai is in such a geographical position that once there is an active monsoon condition, it will get extremely heavy rainfall,” he said.
Earlier, Brihanmumbai Municipal Corporation (BMC) chief Praveen Pardeshi had blamed climate change and Mumbai’s geographical location as an island city for water logging.