Role and value of urban forests in carbon sequestration: review and assessment in Indian context

The role of urban forests in carbon capture and sequestration has been reviewed in a global context. An interpretive analysis was carried out using normalized difference vegetation index (NDVI) and allometric relationships in 5 cities of India, viz. Navi Mumbai, Nagpur, Bengaluru, Leh and Delhi, to evaluate the economic importance of urban green spaces in sequestrating carbon emissions and mitigating severe climatic impacts. NDVI maps were prepared using data from Landsat 7 and Landsat 8 satellite sensors. Bengaluru showed highest carbon sequestration (141.83 MT), and carbon sequestration in the city of Leh was comparatively very low (1.51 MT) as it is a cold desert with a very low urban forest cover. The valuation of urban green spaces in the selected cities was done by using market price method (MPM), value transfer method (VTM), and social cost of carbon method (SCC). The carbon sequestration valuation ranged from 55 to 5164 million$ for estimation using MPM and from 69.69 to 6537.15 million $ for SCC, whereas for VTM it ranged from 1575.06 to 147,736.94 million INR. The SCC approach used for valuation showed the highest cost of CO2 sequestered, while the MPM provided with the lowest value for all the five cities. Highest carbon sequestration and valuation values were observed in Bengaluru followed by Delhi. This study also points to the need of developing region-specific allometric relationships for better accuracy in quantifying carbon sequestration potential and associated economic value of urban forests.