JOINT IMPLEMENTATION AND UNIFORM MIXING

Joint implementation is a hotly debated issue in the context of the Fr amework Convention on Climate Change. The main argument for joint impl ementation is that, since it does not matter where greenhouse gas emis sions are reduced (as these gases mix uniformly in the atmosphere), it is better to do it where abatement is cheapest. Many objections to jo int implementation exist. Here we add one that argues against the unif orm mixing property, Although in the long run the global climate is in sensitive to the place where abatement is undertaken, in the short run the regional climate changes with the induced changes in the albedo. Indeed, reduction of the atmospheric load of sulphate aerosols and alb edo changes associated with land cover change may well lead to acceler ated warming in the region of abatement. This is undesirable as the ra te of climatic change is a major determinant of the damage done. Hence , the discussion on joint implementation is further complicated.