23 November 2006 Past and Current Trends in Global Anthropogenic Sulphur Emissions

A recent paper by a British researcher shows a 22% decline in global anthropogenic sulphur emissions during the 1990s. Local air pollution and smog levels will be improved if this trend is maintained. Nevertheless, global warming may be aggravated.

Sulphur has many industrial applications, such as batteries, detergents and fungicides. Sulphuric acid, for example, is one of the most important raw materials for industry. Nevertheless, sulphur plays a role in three important environmental problems: local air pollution and smog, acid rain, and global climate change. A recent study has analysed the trend in global anthropogenic sulphur emissions. To this end, the author collected data for most countries of the world from 1850 to 2000. The author used previously published data, which was brought together for the first time, and new estimates. Global anthropogenic sulphur emissions increased until the late 1980s. Existing estimates showed a moderate decline from 1990 to 1995 and relative stability through the decade. The new data presented in the paper indicates a 22% decline in emissions in the 1990s to a level not seen since the mid-1960s. In particular, from 1987 to 2000, global emissions declined by 24% and since 1989 they have fallen at an average rate of 2.4% per annum. The decline is evident in North America, Western and Eastern Europe, and in the last few years, in East Asia as well. Furthermore, the author highlights that emissions of sulphur dioxide and other pollutants such as carbon dioxide appear to increase with rising incomes but to decrease over time with technological improvements. Indeed, there is evidence of the diffusion of pollution abatement technologies to developing countries such as China. Therefore, income is neither the only nor the most important factor determining to what degree best practice technology is adopted, as was previously thought. If the observed trend in the global reduction in emissions is maintained, local air pollution and smog problems will be improved. However, global warming may be somewhat exacerbated. This is due to the fact that sulphur emissions, in particular, sulphate emissions, are believed to have an indirect cooling effect through a process known as global dimming. This is due to the fact that sulphate particles in the atmosphere, along with other aerosol particles, bounce sunlight back into space or seed clouds, thus reducing the solar radiation that reaches the Earth’s surface. This effect may have partially masked the effect of greenhouse gases on global warming. In fact, the study shows that solar radiation on the Earth’s surface closely matches the results for sulphur emissions. However, the magnitude of the measured radiation changes is much greater than conventional estimates of the radiation changes due to changes in anthropogenic sulphur emissions. Overall, this study presents new evidence of the decline of global sulphur anthropogenic emissions. It highlights the importance and effectiveness of international efforts to reduce sulphur emissions, such as the 1985 Helsinki Protocol to the Convention on Long-range Transboundary Air Pollution on the Reduction of Sulphur Emissions or their Transboundary Fluxes by at least 30 per cent or the 1994 Oslo Protocol on Further Reduction of Sulphur Emissions. Source: David I. Stern (2006) "Reversal of the trend in global anthropogenic sulphur emissions", Global Environmental Change 16(2): 207-220. For free access click here . Contact: [email protected] Theme(s): Air pollution For more information: Additional information: The EU LIFE programme has funded several projects specifically related to reducing the environmental impact of sulphur. These include the recent Italian project RefinARS (LIFE00 ENV/IT/000012), which developed a means of using an absorbent to recover sulphur and consequently reduce the overall environmental impact of the refining process (see project summary , web-site and layman’s report ). A second example is the Dutch project 'Sulphur Plus' Pilot Plant (LIFE98 ENV/NL/000186), which demonstrated a new technology, known as the ‘Sulphur Plus’ process, which aimed to increase the recovery of sulphur in SO² emissions and thereby reduce atmospheric SO² emissions (see project summary and web-site ). Opinions expressed in this News Alert do not necessarily reflect those of the European Commission To cite this article/service: "Science for Environment policy" : European Commission DG Environment News Alert Service, edited by BIO Intelligence Service.

1 European Commission DG ENV News Alert issue 44

November 2006