change. And in any statutes setting performance standards, language should be included that requires the implementing agency to update the standards based on new scientific and technical information. These sorts of regulatory mechanisms can themselves serve as focal points for agency action and for advocates on all sides of the climate debate to encourage agency responsiveness.

Adaptive policy mechanisms can also be applied to market-based policies. For instance, harvesting caps in fisheries around the world are often set annually, rather than having a fixed cap. The annual cap is based on the best available science on fish stocks for that year. Rights to harvest a specific amount of fish each year (akin to emissions allowances in a cap-and-trade program) are then allocated to rights holders as a percentage of the cap (NRC, 1999). Similarly, Congress could consider providing authority to the administrator of a cap-and-trade program to alter the cap on a periodic basis in response to new information about progress in meeting long-term emissions goals, the cost of pricing mechanisms, and changes in available technologies.

An example of another policy evolution mechanism is Japan’s Top Runner Program, which uses progress in the commercial development of efficiency technology for vehicles and appliances to set efficiency standards. The program works by using the energy performance of the best available technology on the market to set standards. The standards typically take effect 4 to 8 years after the technology is available commercially. For passenger automobiles, for example, Japan set Top Runner standards in 1999 to improve fuel economy by 22.8 percent by 2010; the targets were met by 2005. Preliminary analysis suggests that the program has been quite effective in moving Japan toward its targets for cutting GHG emissions (METI, 2008; Nordqvist, 2006).

Similarly, statutory deadlines that require the adoption of updated efficiency standards for appliances and automobiles can produce policy evolution. As noted above, however, federal agencies have frequently missed statutory deadlines, so care needs to be taken that the responsible agency has sufficient resources and staffing in place to meet deadlines.


The strategies and policies discussed in this report are complex efforts with extensive implications for other domestic issues and for international relations. It is therefore crucial that policies be properly implemented and enforced, and that they be designed in ways that are durable and resistant to distortion or undercutting by subsequent pressures. At the same time, policies will need to be sufficiently flexible to allow for adaptation as we gain experience and understanding. There are inherent tensions

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