71% of Mumbai’s greenhouse gas emissions due to electricity usage: Study
A staggering 71% of the city’s greenhouse gas (GHG) emissions can be attributed to the energy sector, according to a recent analysis by the World Resources Institute (WRI) India. Electricity generated by thermal power plants in peri-urban areas, in turn, consumed within the boundaries of the Mumbai city and suburban districts, emitted a total of 24,235,804 tonnes of carbon dioxide equivalent (tCO2Eq) GHGs in 2019.
The majority contribution of the energy sector is not surprising, given the high domestic demand for power, along with the fact that 95% of all electricity consumed in Mumbai is entirely coal-based. Of the emissions within this 71% bracket, residential electricity usage makes up 55%, while 45% comes from commercial and institutional sources, and 4% from industries.
This is followed by the transport sector, which emitted 82,21,902 tCO2Eq of carbon in 2019, making up 24% of Mumbai’s total GHG emissions. Within this bracket, aviation contributes 45% of all GHG emissions, vehicles 44%, railways 9% and waterways 2%. In keeping with established trends globally, private vehicles, which make up only around 10% of the modal share of transport in Mumbai contributed a disproportionate amount of GHG emissions as compared to mass transit systems like railways (which make up over 40% of the modal split).
These details are part of a ‘GHG inventory’ for Mumbai, created using an Excel-based tool developed by the C40 Cities Climate Leadership Group, called the City Inventory Reporting and Information System (CIRIS). The GHG inventory is one of the preliminary steps undertaken before drafting a dedicated Climate Action Plan (CAP) for the city, which is now expected to be ready by November. HT was the first to report the development on June 25 this year. WRI has been engaged as a consultant for the same by the Municipal Corporation of Greater Mumbai.
The remaining 5% of tCO2Eq emissions are contributed by the waste sector, which in 2019 emitted 18,53,741 tCO2Eq carbon. In all, Mumbai’s annual GHG emissions for the year 2019 stood at a total of 34.3 million tonnes of carbon. This does not include other townships and municipalities in the larger Mumbai Metropolitan Region. Per capita, Mumbai emitted 2.67 tonnes of carbon in 2019, which is higher than the national average of around 1.91 million tCO2E2 per person per year.
The GHG inventory is essentially a baseline assessment that will help to plan emissions reductions for the near term (2030), medium-term (2040) and long-term (2050). With Mumbai expected to join four other Maharashtra cities in the ‘Race to Zero’ campaign, which was founded last December under the United Nations Framework Convention on Climate Change, these targets are ambitious.
“By our commitment to Race to Zero, Mumbai will aim to cut carbon dioxide equivalent emissions in half by 2030 and aim to achieve net-zero emissions by the year 2040,” said Saurabh Punamiya, policy and engagements secretary (private) to Aaditya Thackeray, cabinet environment minister.
The role of greenhouse gases in global warming is well documented, and there is an increasing amount of meteorological evidence to demonstrate the effects of global warming in Mumbai. According to data from the India Meteorological Department’s automatic weather station in Santacruz, for example, the city has recorded annual mean temperature higher than normal for 14 consecutive years, since the year 2007. The ambient temperature trend analysed by WRI using IMD data over the past 47 years shows a steady increase in nighttime temperatures throughout the year. Seasonally, the winter months of November to February are warming up at a fast pace.
This coincides with worrying trends in rainfall patterns. The past 10 years have seen a marked increase in extreme-rainfall-events (EREs), resulting in frequent conditions of waterlogging and flooding. The MCGM’s automatic weather stations (AWS) data suggests that Mumbai sees, on average, six heavy (64.5 – 115.5 mm), five very heavy (115.6 – 204.4 mm), and four extremely heavy (> 204.5 mm) rain events per year, with a marked increase in the number of extremely heavy rain events between 2017 and 2020.
Spatial mapping of these weather stations carried out by WRI shows that localised clusters in the western and central areas of the city — Worli-Dadar, Kurla and Andheri — are most vulnerable. Coastal risks due to storm surge, coastal inundation, and sea intrusion are also exacerbated during monsoon months.
Independent experts were reluctant to comment on the specifics of WRI’s findings, but said that the data prima facie is not unexpected. Dr. Anjal Prakash, research director at the Indian School of Business (ISB) and a lead author of the ongoing 6th Assessment report of IPCC (where he is involved in the chapter on cities, settlements and key infrastructure), said, “I cannot comment on the data as I have not seen it, but there is no doubt that Mumbai is an extremely vulnerable city. It has so far lacked a coherent strategy and vision to develop climate resilience. It is worrying given the signs we are seeing, including increasing cyclones and more heavier, irregular precipitation. There is a deep uncertainty developing around rainfall and severe weather events. Climate action plans needs to posit solutions to this.”