Sierra Club v. County of San Diego

The California Court of Appeal affirmed a trial court judgment that San Diego County’s greenhouse gas mitigation measures for two housing developments were inadequate under CEQA. The appellate court found that the mitigation measures suffered from the same deficiencies that the court previously identified in 2020 in Golden Door Properties, LLC v. County of San Diego for mitigation measures included in EIR for the County’s Climate Action Plan: they lacked enforceable performance standards and they impermissibly delegated and deferred the determination of whether greenhouse gas offsets were real, permanent, verifiable, quantifiable, enforceable, and additional. The court did not weigh in on whether the mitigation measures were compliant with the County’s general plan update since the general plan’s greenhouse gas-related provisions remained in flux due to ongoing litigation and because the mitigation measures had already been deemed not to comply with CEQA.