California is reducing greenhouse gas emissions. Existing laws and regulations have put the state on track to meet our aggresive climate goals for 2020 and 2030. That’s the good news.
But we need to do a lot more to avoid catastrophic warming in the longer term. That’s the difficult news.
The good news and the difficult news both come from a new study by Jeffery Greenblatt, a scientist at the Lawrence Berkeley National Laboratory. He has modeled the effects of current and proposed state policies and then compared them to the disastrous result if all climate laws were repealed, which he labels Counterfactual (S0). Under other potential scenarios, Greenblatt writes, “not only will California meet its 2020 reduction goals under AB 32, but it could achieve reductions of at least 40 percent below that level in the 2030 time frame.”
The study, “Modeling California policy impact on greenhouse gas emissions,” has been published in Energy Policy. Besides the counterfactual, Greenblatt develops three other scenarios. Committed Policies (S1 in the chart) “have the force of law and are being implemented,” such as efficiency improvements in light-duty vehicles, building energy efficiency standards, and the mandate for 33 percent renewable electricity generation. S1 yields a modest reduction in greenhouse gases to 2020, but after that it flattens out and begins to creep upward.
Uncommitted Policies (S2) lack detailed implementation plans or firm financial support, but all of these policies have been credibly proposed. Examples are new efficiency targets for buildings, completion of high-speed rail, and increased biofuels use. S2 also meets the targets for 2020, but later reductions are disappointingly gradual.
The third path, Potential Policies and Technologies (S3), projects a more hopeful future. It includes some speculative changes, including aggressive vehicle efficiency improvements, building electrification, and a more stringent renewable portfolio standard. S3 achieves the targets for greenhouse gas emissions for 2020 and for 2030, when we need to be 40 percent below 1990 emissions.
The target for 2050 is for California to emit a daunting 80 percent less than we did in 1990, and not even S3 achieves that essential result. Fortunately, Greenblatt’s research outlines a method for devising new policies to reach the 80 percent target. He explains:
One of the most important results of this study is that the GHG [greenhouse gas] impact of each individual policy is quantified for the first time. This allows policymakers to compare policies in different sectors and evaluate trade-offs…. Additional policies beyond those in S3 would be needed to continue reduction beyond 2050, but focusing on cumulative reductions may offer a more flexible policy framework.
The takeaway from Greenblatt’s study is that we can be pleased at the strides California has taken. Laws like AB 32 and stringent regulations have begun to reduce greenhouse gas emissions significantly. But we cannot become complacent. Continued effort and innovative policies are essential if we want to remain on the path toward a livable planet.