Over the last few decades, 30 states and Washington, D.C., have enacted renewable portfolio standard (RPS) programs. These programs vary substantially, with most states having a restriction or preference with respect to whether renewables are located in-state or in-region. This Article takes a cross-disciplinary approach to analyzing these programs: first, by looking at how geographic limitations may run afoul of the dormant Commerce Clause (DCC); and second, by considering empirical research on how geographic provisions affect RPS programs’ cost-effectiveness. Prohibiting or restricting out-of-state renewables from counting toward RPS requirements is likely unconstitutional, but policies applying on a regional basis or pursuing a practical aim are likely to be viewed more favorably by courts. The DCC thus plays an important role in improving uniformity among state RPS programs and promoting free trade and efficiency.

In July 2021, the European Commission published a proposal for a Carbon Border Adjustment Mechanism (CBAM), part of a wider package of laws aimed at implementing the European Union (EU) Green Deal. The exact design of the CBAM is in flux, and priorities will have to be set. The chief concern is the compatibility of a CBAM with the law of the World Trade Organization (WTO). This Article explores whether and how the various CBAM design options under consideration can be reconciled with WTO requirements, focusing on a possible import border adjustment scheme. Last issue’s Part One described different instruments under consideration for the EU’s proposal; this part assesses the validity of these measures against the public policy exceptions contained in Article XX of the General Agreement on Tariffs and Trade, and concludes. The measure will require careful design, and even then there is legal uncertainty in the WTO jurisprudence. In any event, the EU will be required to intensify its efforts to reach out to other jurisdictions to come to globally coordinated solutions.

In 2009, when carbon dioxide (CO2) levels were at 387.43 parts per million, the Center for Biological Diversity and 350.org submitted a citizen petition calling on the U.S. Environmental Protection Agency to take steps necessary to institute a national ambient air quality standard (NAAQS) for greenhouse gas (GHG) emissions under §§108-110 of the Clean Air Act (CAA). For 12 years, the petition was simply ignored. Then, the day President Donald Trump left office, outgoing EPA Administrator Andrew Wheeler issued a letter denying the petition. Six weeks later, Acting Administrator Jane Nishida reversed the denial, and the petition remains pending. This Comment addresses the flaws in the denial’s legal and factual reasoning; outlines the technological, scientific, and policy advancements made in the 12 years since the petition was submitted; demonstrates why a GHG NAAQS, particularly one focused on CO2, meets the statute’s purpose and programmatic specifics; and presents a 2021 take on climate change policy that explains why a CO2 NAAQS is an essential and mandatory tool in the CAA toolbox for accomplishing the Biden Administration’s climate agenda.