This analysis provides an assessment of net reductions in greenhouse gas (GHG) emissions relative to total U.S. emissions that could be achieved by pollution reduction proposals currently under consideration in the 111th Congress. This assessment is an update to a previous analysis WRI released on December 17, 2009, and includes an analysis of the American Power Act (APA), introduced as a discussion draft on May 12, 2010 by Senators Kerry and Lieberman. The APA draft is compared against S. 2877, the Carbon Limits and Energy for America’s Renewal Act (CLEARA) as introduced by Senators Cantwell and Collins, and H.R. 2454, the American Clean Energy and Security Act (ACESA) sponsored by Representatives Waxman and Markey, as passed by the House of Representatives June 26, 2009.