A number of congressional proposals to advance programs designed to reduce greenhouse gases have been introduced in the 110 th Congress. Proposed Senate Legislation: Comparison of S. 1766 and S. 2191

S. 1766 . Senators Lieberman and Warner introduced S. 2191 on October 18, 2007. On May 20, Senator Boxer introduced S. 3036 , which is identical to the reported version of S. 2191 except that it contains the above deficit reduction amendment. On June 2, 2008, the Senate invoked cloture on a motion to proceed on S. 3036 . In the case of these alternatives, S. 2191 leans toward the quantity (total emissions) side of the equation; S. 1766 leans toward the price side of the equation. The reduction targets under S. 1766 are not as stringent as the emissions cap under S. 2191 , as discussed earlier. Conclusion

The two proposals— S. 1766 and S. 2191 —would establish market-based systems to limit emissions of greenhouse gases. However, the proposals differ in how those systems would work. S. 2191 would establish an absolute cap on emissions from covered entities, and would allow entities to trade emissions under that cap. S. 1766 would establish emissions targets on covered entities and allow those entities to meet those targets, either through trading program or by making a safety valve payment in lieu of reducing emissions. Under both proposals, short-term U.S. emissions would likely be below a business-as-usual scenario, although reductions under S. 2191 are guaranteed and projected to be larger, particularly over the long-term. In contrast, the cost of S. 1766 is likely to be less and more predictable than S. 2191 . Hence, a major policy question is whether one is more concerned about the possible economic cost of the program and therefore willing to accept some uncertainty about the amount of reduction received (i.e., a safety valve); or one is more concerned about achieving a specific emission reduction level with costs handled efficiently, but not capped (i.e., pure tradeable permits).
Several proposals designed to address greenhouse gases have been introduced in the 110th Congress. Two proposals, S. 1766, introduced by Senators Bingaman and Specter, and S. 2191, introduced by Senators Lieberman and Warner and reported by the Senate Committee on Environment and Public Works on May 20, 2008, are receiving increased scrutiny in preparation for Senate debate on S. 2191. On May 20, 2008, Senator Boxer introduced S. 3036, which is identical to the reported version of S. 2191 except that it contains a proposed budget amendment to make the bill deficit neutral. On June 2, 2008, the Senate invoked cloture on a motion to proceed on S. 3036, allowing discussion of the bill, but not allowing amendments to be introduced. As of June 4, 2008, it is unclear whether the Senate will agree on the motion to proceed, leading to further discussion and allowing amendments to be introduced.
The two proposals—S. 1766 and S. 2191—would establish market-based systems to limit emissions of greenhouse gases. However, the proposals differ in how those systems would work. S. 2191 would establish an absolute cap on emissions from covered entities and would allow entities to trade emissions under that cap. S. 1766 would establish emissions targets on covered entities and allow those entities to either meet emission reduction targets through a trading program or make a safety valve payment in lieu of reducing emissions. Under both proposals, short-term U.S. emissions would likely be below a business-as-usual scenario, although reductions under S. 2191 are guaranteed by the cap and are projected to be larger, particularly over the long-term. In contrast, costs under S. 1766 are likely to be lower and more predictable than under S. 2191.
A major policy question is whether one is more concerned about the possible economic cost of the program and therefore willing to accept some uncertainty about the amount of reduction received (i.e., favoring a "safety valve" like S. 1766); or one is more concerned about achieving a specific emission reduction level with costs handled efficiently, but not capped (i.e., pure tradeable permits as in S. 2191). S. 2191 leans toward the quantity (total emissions) side of the equation; S. 1766 leans toward the price side of the equation.