Transboundary initiatives for controlling sulphur, and possible lessons for CO2

This paper addresses the concept of joint implementation as it relates to the Oslo Protocol of the Convention on Long–Range Transboundary Air Pollution. It introduces the complexity of emissions trading arising from the spatial nature of the pollutant, describes a system for establishing sulphur emission 'exchange rates' between host and donor parties, and illustrates these concepts using a hypothetical trading relationship between Sweden and Estonia. The paper highlights the fact that these trading relations are highly dependent on the formal rules and conditions under which joint implementation might operate. Finally, it compares the sulphur case with the case of emission abatement under the Framework Convention on Climate Change.