Global warming potential and sustainable management of three land uses in Varanasi

Abstract

Purpose – Varanasi, an ancient city has witnessed the conversion of forest into agricultural lands. The high urbanization rate along with affluent lifestyle is adding another category of land use, i.e. landfill. Such land use changes significantly affect the fluxes of greenhouse gases (GHGs) from soil thus contributing to global warming. The purpose of this paper is to quantify the global warming potential (GWP) of the three land uses in Varanasi city taking into consideration CH4 and CO2.The paper also highlights the land use pattern of Varanasi. Design/methodology/approach – Sites representing land uses under forest, agriculture and landfill were identified in and around the city and measurements of GHG fluxes were conducted periodically using closed static chambers. The GWP from each land use was calculated using the standard formula of IPCC (2007). Findings – Landfill was found to be the land use with the highest GWP followed by agriculture. GWP from forest was negative. The study indicated that conversion of natural ecosystems into man made ecosystems contributed significantly to GHGs emissions. Research limitations/implications – The present research is a seasonal study with inherent uncertainties. To reduce the uncertainties long-term monitoring covering wider spatial area is required. Practical implications – The sustainable use of land along with the increment of forest cover will not only reduce the contribution in GHGs emission, but will also increase the carbon sequestrations thus limiting the implication of climate change. Originality/value – This study is the first of its kind comparing the soil borne emissions from three different land uses in a rapidly urbanizing ancient city, suggesting if there is rapid conversion of forested land into other two land uses there will be considerable increase in global warming. No similar studies could be found in the literature.