Integrating, organizational tools are most useful when they also provide an effective means to assess the existing literature so that new hypotheses can be articulated and new directions can be identified.
One such lesson is that to aggregate representations of mitigation across nations and/or groups may be misleading. Quite simply, the capacity to reduce emissions of GHGs can vary dramatically from nation to nation, sector to sector, region to region, group to group, and timeframe to timeframe.
Secondly, one country can easily display high adaptive capacity and low mitigative capacity simultaneously (or visa versa), even though both capacities share the same list of determinants. In a wealthy nation the damages associated with climate change may focus on a small but well-connected group of people, while the cost of a wide range of adaptation options can, through a well established tax system, be distributed across the entire population. The same country might, however, include another small group of people who would be seriously hurt by most if not all of the wide range of available mitigation options and/or policies. The benefits of mitigation would meanwhile be marginal for most people because they would be distributed widely across the population and spread far into the future. Mitigative capacity could then be small.
Countries most vulnerable to climate change may have the smallest mitigative capacity. Vulnerability to climate change results from high exposure to climate impacts, low adaptive capacity, or both. In the high-exposure case, the opportunity cost, broadly defined, of expending resources to mitigate GHG emissions may be too high. In the case of low adaptive capacity, the factors responsible may also work to diminish mitigative capacity. And in the third case, both deleterious correlations could work to complement each other.
Enhancing any one component of mitigative capacity may (or may not) reduce the (marginal) cost of mitigation, because it either expands the set of possible mitigative options or because it reduces the constraints that stand in the way of their efficient application. Adding to the list of available technological options can, of course, lower the cost of implementing a specific policy designed to accomplish a specific objective, but the additions must be more socially acceptable than the existing alternatives, as well as structurally, socially, politically, and culturally feasible. If not, they will not be adopted. Furthermore, their informational requirements must not exceed the informational capacity of the host country.
A nation, region, or communitys international position can play a significant role in determining its ability to exercise its mitigative capacity, because outside entities can influence the effectiveness of technological options and/or domestic policy alternatives. External forces can have a secondary but nonetheless significant effect on the likelihood that mitigation will occur. Section 1.2 highlights the value of international co-ordination. Trade policies, be they global or the domestic policies of significant trading partners, directly influence national incomes and their distribution. Trade also influences the degree to which a countrys development plans put pressure on its stocks of social, human, and natural capital. Each of these factors subsequently affects the constraints that determine the set of feasible mitigation technologies and policies.
Developing indicators of mitigative capacity could help determine who should be expected to do what in terms of mitigation. Examining the determinants of mitigative capacity can identify weak points in the links required for countries to recognize and to act upon the need for climate mitigation This approach can organize existing information effectively as well as suggest new research directions. Specifically, attention to mitigative capacity underlines the role of instruments and targets in framing policy discussions. There are, typically, multiple targets (environmental improvement being one of them) and multiple instruments to achieve them. Contemplating the determinants of mitigative capacity suggests that there is a benefit from broadening the range of instruments used in climate policy. This may be especially so if climate policy is understood to include mechanisms to achieve environmental goals, sustainability goals, equity goals, and development goals. In this light, mitigative capacity highlights the necessity to observe market failures, political failures, and other failures that might otherwise be overlooked. The fundamental questions are, then, ones of a broad perspective to see exactly how much public policy should be devoted to enhancing mitigative capacity in ways that can help answer questions like Where are the payoffs clearly greater than the costs? or Where is the low-hanging fruit that deserves picking?
Contemplating the complexity of mitigative capacity reveals that the sources of uncertainty in understanding mitigation extend far beyond the boundaries of the uncertainties that cloud how various technologies might be applied and how various policy designs might function. The same determinants of mitigative capacity that bring development, equity, and sustainability factors into play add to the list of these sources, just as they do on the impact side of the climate change calculus. In short, therefore, anticipating how mitigation might evolve, how much it might cost, how effective it might be, and how the costs and benefits might be distributed is just as uncertain as anticipating how systems might adapt to the impacts of climate change and climate variability.
Understanding the determinants of mitigative capacity offers a way of organizing not only the analysis of mitigation, but also the negotiations over how to meet the mitigation challenge. Indeed, enhancing mitigative capacity can be a policy objective in and of itself. The means by which this enhancement might be accomplished can be drawn directly from an understanding of how the determinants work within and across countries, how they might complement one another, and how they might conflict. Of course, the opportunity cost of enhancing mitigative capacity, measured in terms of cost of regressing against other objectives, is critical in evaluating its desirability. It is also clear, given the way in which its determinants can be expected to interact, that enhancing mitigative capacity means more than simply transferring resources from one nation to another. Weakness beyond access to adequate resources can surely impede the capacity to mitigate any stress; and so it follows that these weaknesses can undermine significantly the efficacy of offering or requesting simple financial support.
Broadening the domain of analysis to include concerns of development, equity, and sustainability over multiple time scales adds enormous complexity to policy deliberations. A portfolio of strategies (not just policy instruments) that draw on efficiency and cost-effectiveness, equity, and sustainability considerations may nonetheless offer the promise of identifying new options and synergies that may make the job of implementing climate policy less disruptive to societies and economies. In particular, it may help to broaden the range of winwin options.
Concepts like mitigative capacity can help to clarify the trade-offs within and between this expanded range of options. It can show how the assessment of climate change mitigation opportunities contained in this volume can be used and integrated to confront the problem of climate change most effectively. This is especially true when the broad lessons from WGIII herein are taken in concert with lessons drawn from the assessment provided by WGII (IPCC, 2001) on impacts and adaptation. Many of the determinants of adaptive capacity are essentially the same as those of mitigative capacity. Therefore, a portfolio of policy strategies that enhances the capacity to mitigate most effectively should also be effective in enhancing the capacity to adapt. A number of lessons and directions for future research can be enumerated.
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