In recent weeks, California appellate courts issued two decisions regarding California Air Resources Board (CARB) programs implemented under AB32, the Global Warming Solutions Act, with mixed results. The first decision upheld the legality of a key element of CARB’s cap-and-trade program, the auction of emission credits. In that case, the Third Appellate District rejected an industry challenge and found that the auctions are within the authority granted to CARB by AB32 and are not an illegal tax. In the second case, the Fifth Appellate District delivered a setback—the second in that court—for CARB’s Low Carbon Fuel Standard (LCFS), finding the agency failed under the California Environmental Quality Act (CEQA) to adequately analyze the potential effects of NOx emissions resulting from the increased use of biofuels mandated by the LCFS. CARB was first ordered by the court to correct this CEQA violation in a 2013 writ of mandate, but the agency failed to do so in its 2015 re-adoption of the LCFS. The court, noting the environmental benefits of this program, however, did not invalidate the LCFS and only froze the required standards at 2017 levels until CARB corrects the CEQA deficiencies. These decisions do little to clarify the muddy waters around how agencies should analyze greenhouse gas emissions under CEQA, as that analysis is inextricably intertwined with the effectiveness of the State’s greenhouse gas regulatory programs.