HTAP_v2: a mosaic of regional and global emission gridmaps for 2008 and 2010 to study hemispheric transport of air pollution
Authors: Janssens-Maenhout G. , Crippa M. , Guizzardi D. , Dentener F. , Muntean M. , Pouliot G. , Keating T. , Zhang Q. , Kurokawa J. , Wankmüller R. , Denier van der Gon H. , Klimont Z. , Frost G. , Darras S. , Koffi B. 
Published: April 2015

Abstract. The mandate of the Task Force Hemispheric Transport of Air Pollution (HTAP) under the Convention on Long-Range Transboundary Air Pollution (CLRTAP) is to improve the scientific understanding of the intercontinental air pollution transport, to quantify impacts on human health, vegetation and climate, to identify emission mitigation options across the regions of the Northern Hemisphere, and to guide future policies on these aspects. The harmonization and improvement of regional emission inventories is imperative to obtain consolidated estimates on the formation of global-scale air pollution. An emissions dataset has been constructed using regional emission gridmaps (annual and monthly) for SO2, NOx, CO, NMVOC, NH3, PM10, PM2.5, BC and OC for the years 2008 and 2010, with the purpose of providing consistent information to global and regional scale modelling efforts. This compilation of different regional gridded inventories, including the Environmental Protection Agency (EPA)'s for USA, EPA and Environment Canada's for Canada, the European Monitoring and Evaluation Programme (EMEP) and Netherlands Organisation for Applied Scientific Research (TNO)'s for Europe, and the Model Inter-comparison Study in Asia (MICS-Asia)'s for China, India and other Asian countries, was gap-filled with the emission gridmaps of the Emissions Database for Global Atmospheric Research (EDGARv4.3) for the rest of the world (mainly South-America, Africa, Russia and Oceania). Emissions from seven main categories of human activities (power, industry, residential, agriculture, ground transport, aviation and shipping) were estimated and spatially distributed on a common grid of 0.1° × 0.1° longitude–latitude, to yield monthly, global, sector-specific gridmaps for each substance and year. The HTAP_v2.2 air pollutant gridmaps are considered to combine latest available regional information within a complete global dataset. The disaggregation by sectors, high spatial and temporal resolution and detailed information on the data sources and references used will provide the user the required transparency. Because HTAP_v2.2 contains primarily official and/or widely used regional emission gridmaps, it can be recommended as a global baseline emission inventory, which is regionally accepted as a reference and from which different scenarios assessing emission reduction policies at a global scale could start. An analysis of country-specific implied emission factors shows a large difference between industrialised countries and developing countries for all air pollutant emissions from the energy and industry sectors, but not from the residential one. A comparison of the population weighted emissions for all world countries, grouped into four classes of similar income, reveals that the per capita emissions are, with increasing income group of countries, increasing in level but also in variation for all air pollutants but not for aerosols.