Quantification of agricultural emission: A comprehensive emission inventory of crop residue open burning in Pakistan- 2010-2021

Abstract

In rural areas of Pakistan Crop Residue Open Burning is a prevalent agricultural practice which results in the massive emissions of greenhouse gases, atmospheric particulate, and trace gas pollutants. With WHO setting stringent air quality standards, there is an immediate need for accurate city/district-level air pollution data globally. This study presents an extensive emission inventory of major air pollutant emission resulting from crop residue burning in Pakistan for years 2010-2021, marking a significant step towards improved data availability. To achieve the accurate spatial distribution of emissions, the study combined district level crop production data with MODIS Active fire data at high temporal and spatial resolution (1-day temporal,1 Km spatial). The fire events were specifically identified over croplands of Pakistan using land cover data, provided by European Space Agency/Climate Change Initiative (ESA/CCI), which is available at 300 m spatial resolution. This study has incorporated the most updated emission factor values for considered pollutants. The outcome of this research indicates that the amount of average annual crop residue generated in Pakistan is 75 Tg, out of which 20 Tg is burned on fields. As a result of this burning, the emissions of carbon monoxide have increased from 1.6 Tg in 2010 to 2.1Tg in 2021, accompanied by the average annual increase rate of 2.8%. The corresponding rate for other considered pollutants is found to be 3.1% (CO2), 4.2%(CH4), 2.8% (NMVOCS), 3.5%(N2O), 5.4%(NH3), 3.8%(SO2), 3.1%(NOX), 3.6% (PM 2.5), 3.3% (PM 10), 4.2%(OC), and 3.5%(BC). The assessment of the magnitude and distribution of pollutants and greenhouse gas emissions from crop residue burning is crucial for managing overall air quality of an area. Hence, this study contributes directly to the global efforts to combat climate change and mitigating air pollution.