Climate Change 2001:
Working Group III: Mitigation
Other reports in this collection Institutional Considerations

In contrast to the single-actor paradigm, which assumes that society can be identified with a unique optimizing decision maker, GHG emissions are, in fact, controlled by a multitude of individual agents and multiple decision makers that influence the transformation of individual to collective actions. Thus far, decision analysis has strongly emphasized the most aggregated level of government policy and neglected the multidimensionality of decision-making institutions (Jaeger et al., 1998).

Although there are many country-specific differences in the relationships between national, regional, and local governments, most analysts consider local authorities to be the salient political actors. In addition to acting on their own, local governments serve as an interface between citizens and the nation state, and they are in regular contact with members of the community. O’Riordan et al. (1998) suggest that, as the need for more effective climate policy emerges, it might be useful to broaden the national response strategy to incorporate the local levels and so stimulate the very effective informal institutional dynamics of individuals and households. The rise in the number of informal networks of co-operation dispersed via schools, universities, religious communities and other social groups is regarded as an important step towards including climate change awareness into people’s everyday concerns. This is of great importance, as the individual costs of contributing to climate change are less than the consequent social costs, and thus individual agents generate a changing climate that is socially suboptimal. Becoming aware of the gap between individual and social rationality is assumed to stimulate effective mitigation and adapation measures.

Striking the appropriate balance between mitigation and adaptation will be a tedious process. The need for, and extent and costs of adaptation measures in any region will be determined by the magnitude and nature of regional climate change as a local manifestation of global climate change. How global climate change unfolds will be determined by the total amount of GHG emissions that, in turn, reflects nations’ willingness to undertake mitigation measures. Toth (unpublished) points out that balancing mitigation and adaptation efforts largely depends on how mitigation costs are related to net damages (primary or gross damage minus damage averted through adaptation plus costs of adaptation). Both mitigation costs and net damages, in turn, depend on some crucial baseline assumptions: economic development and baseline emissions largely determine emission reduction costs, while development and institutions influence adaptive capacity.

Different levels of globally agreed limits for climate change (or for atmospheric GHG concentrations, as frequently discussed), entail different balances of mitigation costs and net damages for individual nations. Considering the uncertainties involved and future learning, climate stabilization will inevitably be an iterative process. Nation states will determine their own national targets based on their own exposure and their sensitivity to other countries’ exposure to climate change. The global target emerges from consolidating national targets, possibly involving side payments, in global negotiations. Simultaneously, agreement on burden sharing and the agreed global target determines national costs. Compared to the expected net damages associated with the global target, nation states might reconsider their own national targets, especially as new information becomes available on global and regional patterns and impacts of climate change. This becomes the starting point for the next round of negotiations. It follows from the above that establishing the “magic number” (i.e., the upper limit for global climate change or GHG concentration in the atmosphere) will be a long policy process, hopefully helped by improving science.

Mitigation and adaptation decisions related to anthropogenically induced climate change differ. Mitigation decisions involve many countries, disperse benefits globally over decades to centuries (with some near-term ancillary benefits), are driven by public policy action, based on information available today, and the relevant regulation will require rigorous enforcement. In contrast, adaptation decisions involve a shorter time span between outlays and returns, related costs and benefits accrue locally and their implementation involves local public policies and private adaptation of the affected social agents, both based on improving information. Local mitigation and adaptive capacities vary significantly across regions and over time. A portfolio of mitigation and adaptation policies will depend on local or national priorities and preferred approaches in combination with international responsibilities.

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