Climate change made Mumbai air 30 pc worse in 22-23: Study

A recent study conducted by a team of scientists from the National Institute of Advanced Studies NIAS and the Indian Institute of Tropical Meteorology IITM revealed a contrasting trend in air quality among Indian cities in 202223 While North Indian cities like Ghaziabad Noida and Delhi witnessed a relative improvement in air quality Mumbai experienced a significant deterioration marked by a 30 per cent increase in PM25 levels This shift has been attributed to climate change according to the studyThe studymdashtitled Triple dip LaNina unorthodox circulation and unusual spin in the air quality of Indiamdashwas published in Elseviers international journal lsquoScience of the Total Environmentrsquo It suggests the dominance of higher northerly winds at the transport level forcing an influx and relatively slower winds near the surface trapping pollutants in peninsular India thereby notably increasing PM25 concentrationSimplifying this Dr Gufran Beig the lead author of the study and former director of System of Air Quality and Weather Forecasting And Research SAFAR said ldquoThe impact of stubble burning in the north is due to transportlevel winds which are normally towards Delhi and worsen air quality there Now those winds with PM25 which are 1 km above the surface surpassed Delhi and impacted more of the peninsular India which is unique for those years So stubble burnings impact in Delhi was minimal but it significantly impacted Mumbai and other placesrdquoUsually when these winds reach Delhi due to its close proximity to the stubbleburning regions the air quality worsens to hazardous levels While the impact of these winds towards Mumbai and other peninsula regions was not as bad as what it is in Delhi it was significant enough to cause a dent in the air quality Moreover the natural benefits in air quality control that coastal cities like Mumbai enjoy due to their close oceans were also minimised by these winds from the northern parts of the country the study explainedFor Delhi and other cities in the north it didnt matter that westerly disturbancesmdashwhich bring about rainfall in the winter months helping as a natural pollution control measuremdashwere too feeble as the air quality improved regardless However the same lack of westerly disturbances contributed to poor air in the peninsular region Mumbai saw the worst deterioration in air quality followed by an increase in PM25 levels by Coimbatore 28 per cent Bengaluru 20 per cent and Chennai 12 per centAmong the North Indian cities Ghaziabad registered the most significant improvement with a reduction of 33 per cent PM20 levels followed by Rohtak 30 per cent and Noida 28 per cent Delhi the most critical and landlocked city registered an improvement of around 10 per centLa Nintildea effectThese changes in the weather patterns were attributed to a triple dip in the La Nintildea event from 2020 to 2023 Other tripledip La Nintildea events recorded since 1950 were in 19982001 19731976 and 19541956ldquoEven as such dips have happened not too long ago their severity matters So what we are saying is that the severity brought about by the recent dip was because of climate changerdquo Dr Beig saidLa Nintildea is when coolerthanaverage sea surface temperatures are recorded in the central and eastern Pacific Ocean often leading to weather patterns such as increased rainfall in some regions and droughts in others ldquoThis is a normal phenomenon that lasts about nine to twelve months The wind changes but the impact does not affect air qualityrdquo Dr Beig saidThe root cause of air pollution and climate change which impacts human health and food security adversely is the increasing emissions of chemical constituents which include fossil fuels and biofuels from industries and thermal power plants among other emission sources This is also true for MumbaildquoSuch episodes in all probability are set to increase by leaps and bounds if a number of drastic steps are not taken to target the root cause of deteriorating air quality and climate changerdquo the study concludes1037Level of improvement in Delhi airA recent studySuch episodes in all probability are set to increase by leaps and bounds if a number of drastic steps are not taken to target the root cause of deteriorating air quality and climate changersquo