To include issues of cost-effectiveness, distribution (narrowly defined), equity (more broadly defined), and sustainability adds enormous complexity to discussions on the problem of how nations can respond best to the threat of climate change. Indeed, recognition that these multiple domains are relevant complicates the task assigned to policymakers and international negotiators by opening their deliberations to issues that lie beyond the boundaries of the climate change problem, per se. Their recognition thereby underscores the need to integrate scientific thought across a wide range of new policy-relevant contexts, but not simply because of some abstract academic or narrow parochial interest advanced by a small set of researchers or nations. Cost-effectiveness, equity, and sustainability have all been identified as critical issues by the crafters of the UNFCCC, and they are an integral part of the charge given to the drafters of TAR. Integration across the domains of cost-effectiveness, equity, and sustainability is therefore profoundly relevant to policy deliberations according to the letter as well as the spirit of the Framework Convention itself.

One important preliminary step towards integration of the three perspectives that is developed in the body of this report is the use of ancillary and co-benefits, developed and assessed most fully in Chapters 7 and 8 and referred to in many of the other chapters, that could be used to augment mitigation cost estimates produced by the cost-effectiveness approach. Thus, one could add or subtract an estimate of the equivalent cost or benefits on various equity or sustainability metrics (e.g., changes in the extent of poverty, human capital development, etc.) that would result from specific mitigation policies. Although this would be a start on a more integrated quantitative assessment of costs, it would initiate a debate on how these other metrics ought to be evaluated and aggregated. This may make it desirable to move to a broader integrating framework where multiple policies could be evaluated according to multiple metrics simultaneously. The development of the concept of “mitigative capacity” is one new, but promising, step towards the development of the systematic evaluation of mitigation options from an integrated cost-effectiveness, equity, sustainability perspective.

Yohe (2001, in press) has recently introduced mitigative capacity as an organizing tool to aid policymakers and analysts alike as they try to accomplish this integration. Briefly defined, a nation’s mitigative capacity reflects its ability to diminish the intensity of the natural (and other) stresses to which it might be exposed. The list of stresses for any particular nation might include climate change and climate variability, of course. It follows that to review the diversity of the determinants of mitigative capacity from a climate perspective can help assessors who contribute to IPCC Assessments and researchers who will look to their report for guidance in setting their research agendas. These determinants can, in short, provide a framework upon which to build and through which to assess systematic and comparable representations of nations’ relative capacities to cope. Mitigative capacity is therefore offered here as one means with which to integrate and to evaluate the complex issues that have emerged since the publication of SAR. There may be other means to the same end, of course, but a focus on mitigative capacity has the virtue of concentrating attention directly on the problem at hand–climate change mitigation.

IPCC Homepage