O3, PM, Hg, and POPs are significant environmental problems in many regions of the world. Mitigation of intercontinental transport is not a substitute for emission reductions at the local and regional scale. In most cases, concentrations within a source region are more sensitive to emission changes within that region. However, without further international cooperation to mitigate intercontinental flows of air pollution, it is likely that many nations will not be able to meet their own goals and objectives for protecting public health and environmental quality over the next 20 to 40 years.
Efforts to mitigate the sources of intercontinental flows of air pollutants result in significant benefits for both the source and receptor countries in terms of decreased impacts on public health, decreased damage to ecosystems, and depending on the mix of pollutants, decreased contribution to climate change. In fact, countries outside of a source region may benefit collectively more from emission decreases in a source region than the source region itself. One country’s actions can also lessen the costs of emissions control needed in other countries. Thus, there are significant benefits to both source and receptor countries to cooperate in decreasing emissions that contribute to intercontinental transport of air pollution.
The availability of forums for pursuing further international cooperation to mitigate sources of intercontinental transport differs depending on the pollutants of interest. The Stockholm Convention on Persistent Organic Pollutants and the Minamata Convention on Mercury Pollution provide forums for furthering global cooperation to mitigate sources of POPs and Hg.
A range of approaches has been suggested for establishing global or hemispheric scale cooperation on mitigation of O3 and PM, including negotiating a new international agreement; incorporating O3 and PM into an existing global agreement, such as the United Nations Framework Convention on Climate Change (UNFCCC) or the Vienna Convention on the Protection of the Ozone Layer; expanding the geographic scope of the LRTAP Convention; or developing a global framework for cooperation within existing regional agreements.