Set out below is a summary of the key findings of this peer-reviewed study. The aggregate range of potential federal reductions in key sectors is provided first, based on assessments from available literature on what is technically feasible, as well as the corresponding regulatory ambition required to achieve the technically feasible reductions. An explanation of how potential reductions were assessed for each sector and/or category of sources follows, including: (a) a description of the sector or category of sources affected; (b) a discussion of the regulatory policy or policies available to achieve reductions in the sector or category of sources; and (c) an explanation of how available studies were used to construct three potential reduction scenarios for each sector or category of sources.