ANALYZING THE CONFLICTING REQUIREMENTS OF THE FRAMEWORK CONVENTION ONCLIMATE-CHANGE

The objectives of the Framework Convention on Climate Change imply the conflicting constraints of minimising concentrations and maximising e missions (i.e. minimising emission restrictions). Carbon cycle models are readily used for 'forward' calculations of future CO2 given specif ied emissions and the 'inverse' problem of deducing the emissions requ ired to achieve specified concentration profiles. However these approa ches (a) are each geared to only one side of the problem; and (b) each requires the specification of a particular pathway in terms of either emissions or concentrations. These limitations can be avoided by anal ysing the relations between future emissions and concentrations of CO2 using a formalism that optimises over all possible future emission pr ofiles, subject to relevant constraints on both emissions and concentr ations. We present specific calculations indicating which combinations of upper bounds on concentrations and lower bounds on emissions are m utually inconsistent and which are consistent. We also calculate the ( smaller) consistency regions that apply if emission reductions are res tricted to less than 0.5% p.a. or less than 1% p.a. In each case, two reference periods (1990-2100 and 1990-2200) are considered.