On December 9, 2011, the Nicholas Institute for Environmental Policy Solutions convened a broad range of stakeholders representing numerous viewpoints to explore  issues surrounding CAA §111(d), including options for states to demonstrate that existing GHG policies are equivalent to the §111(d) requirements. This Article builds upon the discussion during the December 9 workshop and considers some of the major challenges associated with categories of potentially “equivalent” state programs. Although setting the standard and deciding what level of detail to include in the guidance to the states is an important part of the §111(d) rulemaking, the goal of this Article is not to predict how the Agency will act or to offer an opinion as to how the Agency should act. Rather, the goal is to examine the options available for states to demonstrate
that existing GHG policies are equivalent to the §111(d) requirements, and the challenges that may face the states and the Agency regarding equivalency.