Mutual help for countries with emissions targets

* "Joint implementation" is a programme under the Kyoto Protocol that allows industrialized countries to meet part of their required cuts in greenhouse-gas emissions by paying for projects that reduce emissions in other industrialized countries. In practice, this will likely mean facilities built in the countries of Eastern Europe and the former Soviet Union -- the "transition economies" -- paid for by Western European and North American countries.

* The sponsoring governments will receive credits that may be applied to their emissions targets; the recipient nations will gain foreign investment and advanced technology (but not credit toward meeting their own emissions caps; they have to do that themselves). The system has advantages of flexibility and efficiency. It often is cheaper to carry out energy-efficiency work in the transition countries, and to realize greater cuts in emissions by doing so. The atmosphere benefits wherever these reductions occur.

* The operation of the joint implementation mechanism is similar to that of the "clean development mechanism" (see related sub-chapter) -- and similarly complicated. To go ahead with joint implementation projects, industralized countries must meet requirements under the Protocol for accurate inventories of greenhouse-gas emissions and for detailed registries of emissions "units" and "credits" (steps that also are required for the international trading of emissions on the "carbon market"). If these requirements are met, countries may carry out projects and receive credits beginning in 2008.

* A pilot phase begun in 1995 allowed countries to gain experience in cooperating and in sharing technology. Most of the numerous pilot projects carried out will not be translated into credits under the Protocol, but schemes begun after 1 January 2002 which meet all requirements may be registered under the joint implementation programme.

* If industrialized countries have not yet set up approved registries and greenhouse-gas inventory systems -- complicated technical and bureaucratic hoops some nations still have to jump through -- they may carry out joint-implementation projects under a "second track" process that involves greater international oversight. The oversight, which may be assigned to private companies, will ensure that emissions actually are reduced, and will certify by how much.