local actions, while tough choices are made about the extent to which national policies should prevail. In some instances, it may be appropriate to limit state and local authority and instead mandate compliance with minimum national standards. But Congress could promote regulatory flexibility and innovation across jurisdictional boundaries when this is consistent with effective and efficient national policy. To this end, we suggest that Congress avoid punishing or disadvantaging states (or entities within the states) that have taken early action to limit GHG emissions, avoid preempting state and local authority to regulate GHG emissions more stringently than federal law without a strong policy justification, and ensure that subnational jurisdictions have sufficient resources to implement and enforce programs mandated by Congress.

Design policies that balance durability and consistency with flexibility and capacity for modification as we learn from experience (see Chapter 8).

The strategies and policies outlined above 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 be designed in ways that are durable and resistant to distortion or undercutting by subsequent pressures. At the same time, policies must be sufficiently flexible to allow for modification as we gain experience and understanding (as discussed earlier in this Summary). Transparent, predictable mechanisms for policy evolution will be needed.

There are inherent tensions between these goals of durability and adaptability, and it will be an ongoing challenge to find a balance between them. Informing such efforts requires processes for ensuring that policy makers regularly receive timely information about scientific, economic, technological, and other relevant developments. One possible mechanism for this process is a periodic (e.g., biennial) collection and analysis of key information related to our nation’s climate change response efforts. This effort could take the form of a “Climate Report of the President” that would provide a focal point for analysis, discussion, and public attention and, ideally, would include requirements for responsible implementing agencies to act upon pertinent new information gained through this reporting mechanism.