For California to meet its climate goals, there must be swift, bold infrastructure changes that facilitate decarbonization of the transportation sector. The California Supreme Court’s decision in Cleveland National Forest Foundation v. San Diego Association of Governments (Cleveland) is a mixed bag for those who would use the California Environmental Quality Act (CEQA) to achieve such infrastructure changes. The case originated in 2011 after the San Diego Association of Governments (SANDAG) prepared its 2050 Regional Transportation Plan (RTP) and, pursuant to CEQA, accompanying draft Environmental Impact Report (EIR), prompting Cleveland National Forest Foundation and others to broadly challenge the EIR’s sufficiency. In 2017, the California Supreme Court took up and decided one, narrow issue in Cleveland: whether the EIR adequately discussed how the RTP’s projected emissions departed from California Executive Order S-03-05 (the Order) and its 2050 goal of reducing total state greenhouse gas emissions 80 percent below 1990 levels. While the court left open the possibility for future state-supported projects to skimp on climate emission reductions, it also indicated that future EIRs will be held to a standard consistent with the legislative and technological context at the time of their drafting—an evolving and increasingly stringent standard. This In Brief first discusses the uncertainties the court left open by issuing such a narrow holding; then it analyzes the court’s dicta, indicating what the court will consider important in future decisions; and finishes with a review of guidance issued since this decision that matches the kinds of resources the court mentioned.