The 1979 Convention on Long-Range Transboundary Air Pollution (LRTAP), the first multilateral agreement addressing transboundary air pollution, created a regional framework applicable to Europe, North America and Russia and former East Bloc countries for reducing transboundary air pollution and better understanding air pollution science. LRTAP has contributed to a dramatic decline in air pollution emissions in the region, particularly for sulfur, and economic growth and air pollution trends have been progressively decoupled.
The Convention has 51 Parties and eight protocols, most of which address specific pollutants. LRTAP is a convention in the United Nations Economic Commission for Europe (UNECE). The United States joined the Convention in 1981 and is a party to four of the protocols, including the 1998 Protocol on Heavy Metals and the 1999 Gothenburg Protocol. The Heavy Metals Protocol aims to control emissions of lead, cadmium and mercury that are caused by anthropogenic activities and that are subject to long-range atmospheric transport. The Gothenburg Protocol seeks to reduce the harmful effects of air pollution such as acid rain and ground-level ozone by targeting emissions of sulfur dioxide, nitrogen oxides, and volatile organic compounds.
LRTAP has enjoyed a series of successes in recent years. In 2012, the Parties adopted amendments to both the Gothenburg Protocol and the Protocol on Heavy Metals. Amendments to the Gothenburg Protocol updated targets to further reduce emissions of harmful air pollutants and that added measures to address particulate matter, including black carbon. The amended Gothenburg Protocol is the first international agreement addressing black carbon. The amendments to both protocols also introduced more flexibility in how obligations are implemented, without sacrificing effectiveness. The United States ratified the amended Protocol on Heavy Metals in 2015, and the amended Gothenburg Protocol in 2017.