Atmospheric Environment 33 (1999) 3435}3444 Estimating historical anthropogenic global sulfur emission patterns for the period 1850}1990 Allen S. Lefohn*, Janja D. Husar, Rudolf B. Husar A.S.L. and Associates, 111 North Last Chance Gulch, Helena, Montana 59601, USA Center for Air Pollution Impact and Trend Analysis (CAPITA), Washington University, St. Louis, Missouri 63130, USA Received 13 March 1998; received in revised form 21 January 1999; accepted 3 February 1999 Abstract It is important to establish a reliable regional emission inventory of sulfur as a function of time when assessing the possible e!ects of global change and acid rain. This study developed a database of annual estimates of national sulfur emissions from 1850 to 1990. A common methodology was applied across all years and countries allowing for global totals to be produced by adding estimates from all countries. The consistent approach facilitates the modi"cation of the database and the observation of changes at national, regional, or global levels. The emission estimates were based on net production (i.e., production plus imports minus exports), sulfur content, and sulfur retention for each country's production activities. Because the emission estimates were based on the above considerations, our database o!ers an opportunity to independently compare our results with those estimates based on individual country estimates. Fine temporal resolution clearly shows emission changes associated with speci"c historical events (e.g., wars, depressions, etc.) on a regional, national, or global basis. The spatial pattern of emissions shows that the US, the USSR, and China were the main sulfur emitters (i.e., approximately 50% of the total) in the world in 1990. The USSR and the US appear to have stabilized their sulfur emissions over the past 20 yr, and the recent increases in global sulfur emissions are linked to the rapid increases in emissions from China. Sulfur emissions have been reduced in some cases by switching from high- to low-sulfur coals. Flue gas desulfurization (FGD) has apparently made important contributions to emission reductions in only a few countries, such as Germany.  1999 Elsevier Science Ltd. All rights reserved. Keywords: Anthropogenic; Global; Sulfur; Emissions; Production; Retention; Fossil fuel 1. Introduction Concerns about (1) anthropogenic aerosols a!ecting possible global change (Charlson et al., 1992) and (2) acid rain e!ects on the environment (Legge and Krupa, 1990) have prompted interest in the transformation and fate of sulfur in the atmosphere. Aerosols theoretically have the ability to cool the atmosphere and thus, anthropogenic sulfate particles may be an important factor in the cli- mate system (Charlson et al., 1992). Their in#uence might * Corresponding author.  Note: For those wishing to obtain the electronic version of the database derived from this study, the information can be downloaded from the following Internet address: http://ourworld.compuserve.com/homepages/ASL } ASSOCIATES/ be relatively small regionally, or perhaps counter the entire e!ect of greenhouse warming in the Northern Hemisphere (Charlson et al., 1992). The Intergovernmen- tal Panel on Climate Change (IPCC) report (IPCC, 1994) recon"rmed the ability of aerosols to a!ect climate by changing the radiative balance of the atmosphere. The development of a reliable regional emission inven- tory of sulfur as a function of time is an important "rst step in assessing the potential impact of sulfate aerosols on climate. A global sulfur emission inventory provides data for (1) global pollution models; (2) comparisons of sulfur emission patterns and atmospheric sulfur concen- trations; and (3) emission projections. Estimations of sulfur dioxide emissions since the mid 1800s have been made by Bettelheim and Littler (1979), Dignon and Hameed (1989), Husar and Husar (1990), O G rn et al. 1352-2310/99/$ - see front matter  1999 Elsevier Science Ltd. All rights reserved. PII: S 1 3 5 2 - 2 3 1 0 ( 9 9 ) 0 0 1 1 2 - 0