Despite uncertainties about the nature and stringency of commitments in future climate change agreements, some things are clear: the international negotiations not only will include national targets and timetables, but also will have to take account of diverse policies and measures undertaken by individual nations, including developing countries. The international community will face twin challenges of judging the equity and integrity of various national proposals.
Ex post, determining whether particular policies have been implemented is a relatively simple matter, even though assessing their effectiveness is not always straightforward. Ex ante, however, the integrity of the international process requires at least some evaluation of the policies and measures proposed by individual nations to estimate their likely impacts. The absence of such evaluation may handicap the negotiators in reaching credible agreements.
The current system for reporting national actions to the international community is highly non-uniform and insufficient to understand differences among countries’ policies and their effectiveness. Thus, a first order of business should be the development of a much tighter, narrowly defined set of guidelines designed to reflect genuine differences in activities among nations.
The problem with evaluating equity is that clear metrics are rarely fair, and fair metrics are rarely clear. Certain metrics, like emissions per unit of Gross Domestic Product (GDP), population, or historical emissions, are straightforward to calculate and generally informative but they are imperfect indicators of burden. Other metrics, like emissions reductions or total costs of policies undertaken, are unlikely to be reported reliably. The metric of marginal abatement costs—at least among market-based policies—has the advantage of indicating the cost-effectiveness of the international distribution of effort.