Sub-region (district) and sector level SO2 and NOx emissions for India: assessment of inventories and mitigation flexibility

Sub-regional and sector level distribution of SO2 and NO, emissions invento ries for India have been estimated for all the 466 Indian districts using b ase data for years 1990 and 1995. Although, national level emissions provid e general guidelines for assessing mitigation alternatives, but significant regional and sectoral variability exist in Indian emissions. Districts rea sonably capture this variability to a fine grid as 80% of these districts a re smaller than 1 degrees x 1 degrees resolution with 60% being smaller tha n even 1/2 degrees x 1/2 degrees, Moreover, districts in India have well-es tablished administrative and institutional mechanisms that would be useful for implementing and monitoring measures. District level emission estimates thus offer a finer regional scale inventory covering the combined interest s of the scientific community and policy makers. The inventory assessment m ethodology adopted is similar to that prescribed by the Intergovernmental P anel on Climate Change (IPCC) for greenhouse gas (GHG) emissions. The secto ral decomposition at district level includes emissions from fossil fuel com bustion, non-energy emissions from industrial activities and agriculture. T otal SO2 and NOx emissions from India were 3542 and 2636 Gg, respectively ( 1990) and 4638 and 3462 Gg (1995) growing at annual rate of around 5.5%. Th e sectoral composition of SO2 emissions indicates a predominance of electri c power generation sector (46%). Power and transport sector emissions equal ly dominate NOx emissions contributing nearly 30% each. However, majority o f power plants are situated in predominantly rural districts while the latt er are concentrated in large urban centers. Mitigation efforts for transpor t sector NOx emissions would therefore be higher. The district level analys is indicates diverse spatial distribution with the top 5% emitting district s contributing 46.5 and 33.3% of total national SO2 and NOx emissions, resp ectively. This skewed emission pattern, with a few districts. sectors and p oint sources emitting significant SO2 and NOx, offers mitigation flexibilit y to policy makers for cost-effective mitigation. (C) 2001 Elsevier Science Ltd. All rights reserved.