Research Projects

According to the Global Methane Assessment (UNEP), limiting global warming to 1.5°C requires a reduction of anthropogenic methane (CH₄) emissions by 40–45% (~180 million tonnes/year) by 2030, relative to 2020 levels. Methane, a short-lived climate pollutant with a ~10-year atmospheric lifetime, is over 80 times more potent than CO₂ over a 20-year timescale. Since pre-industrial times, atmospheric CH₄ levels have more than doubled, making it the second-largest contributor to global warming after CO₂. Methane also plays a role in forming ground-level ozone, a pollutant responsible for nearly half a million premature deaths annually and reduced agricultural productivity due to suppressed plant growth. Over the Indian subcontinent, CH₄ concentrations rose from 1700 to 1950 ppb, with an average annual increase of 8.76 ppb yr⁻¹. Hotspots such as the Indo-Gangetic Plain and northwest India are driven by emissions from agriculture, wetlands, and urban-industrial activities (Venkata et al., 2024). Among South Asian countries, India showed the highest CH₄ increase (15.9–19.6 ppb yr⁻¹), followed by Bangladesh, while Myanmar and Indonesia showed the lowest. Although satellite-based analyses have improved regional emission estimates, detailed spatiotemporal data within Indian cities remains sparse—particularly from urban wetlands, which exhibit wide seasonal variability but are often overlooked. Wetlands are among the most significant natural sources of CH₄, contributing 25–40% of global emissions (Knox et al., 2019; Saunois et al., 2020). Their emissions drive year-to-year variability in atmospheric CH₄ (Peng et al., 2022), with flux rates depending heavily on wetland type. Coastal wetlands like salt marshes and mangroves typically emit less CH₄ than inland freshwater marshes (Liu et al., 2020; Zhang et al., 2022). According to IPCC AR6, global CH₄ emissions from natural wetlands range between 150 and 180 Tg CH₄ yr⁻¹, while earlier estimates reached up to 284 Tg CH₄ yr⁻¹, reflecting methodological and geographical differences. In India, northern inland wetlands emit CH₄ at approximately 150–600 mg CH₄-C m⁻² day⁻¹ (~0.2–0.8 mmol CH₄ m⁻² day⁻¹), while coastal wetlands show wider variability—from ~0.02 to several mmol CH₄ m⁻² day⁻¹ depending on pollution levels. For Delhi, wetland CH₄ emissions in 2009 were estimated at ~1.5 Gg. However, comprehensive data from the National Capital Region (NCR) remain limited due to: Scarcity of field-based flux measurements; Dependence on environmental factors (e.g., season, substrate, vegetation); and Outdated or spatially limited datasets. To improve accuracy, the following steps are needed: Field Monitoring: Conduct chamber or eddy covariance flux measurements across seasons. Bottom-Up Inventories: Use current satellite-derived land use data and high-resolution wetland maps. Top-Down Integration: Combine satellite CH₄ observations (e.g., TROPOMI, GOSAT) with bottom-up models.