Greenhouse gas emissions of Delhi, India: A trend analysis of sources and sinks for 2017-2021

Delhi is the world's second most populated city and India's capital. The objective of this study is to develop a comprehensive emission inventory of GHGs, including CO2, N2O, and CH4, and present a source apportionment of GHGs, thus setting a benchmark for developing source-specific mitigation strategies at a localized level. The study employs 2006 IPCC and Good Practice Guidelines to analyze and quantify emissions from various sources. An annual emission load of 51,081 ktCO2e for Delhi from 2017 to 2021 is estimated with an uncertainty of approximately 4%. 34,344 ktCO2e (61%) is accounted for by the stationary combustion sector. The mobile combustion sector accounts for 33% of the total emissions at 18,574 ktCO2e. The waste sector accounts for 5.2% of total emissions, followed by a meagre 0.8% contribution from the agriculture sector. It further evaluates the role of carbon stock in reducing the net emissions generated by the city. This study contributes to future policies by corroborating the findings of a GHG inventory of Delhi from 2017 to 2021 and noting significant variations in the trends in terms of the contribution of different sources to net emissions. It further reinforces the need to develop more localized inventories to target the primary emitting sectors in different regions through focused mitigation strategies.