On Monday, September 10, 2018, two days before kicking-off the Global Climate Action Summit he is co-hosting in San Francisco, California Governor Jerry Brown signed SB 100 (De León), The 100 Percent Clean Energy Act of 2018, which sets a state policy that eligible renewable energy and zero-carbon resources supply 100 percent (%) of all retail sales of electricity in California by 2045. (Our summary of SB 100 is here.)

Perhaps even more importantly, at the same signing ceremony, the Governor also issued a new executive order (EO), EO B-55-18 To Achieve Carbon Neutrality, establishing a new statewide goal “to achieve carbon neutrality as soon as possible, and no later than 2045, and achieve and maintain net negative emissions thereafter.” EO B-55-18, § 1. The EO says that this new goal “is in addition to the existing statewide targets of reducing greenhouse gas emissions.” Id. Those include the targets previously established by Governor Brown and the Legislature of reducing emissions to 40% below 1990 levels by 2030 (by EO B-30-15 and SB 32 in 2015 and 2016, respectively) and a decade earlier by Governor Arnold Schwarzenegger of reducing emissions to 80% below 1990 levels by 2050 (by EO S-3-05).

Governor Brown’s new order requires the California Air Resources Board (CARB) to “work with relevant state agencies to ensure future Scoping Plans identify and recommend measures to achieve the carbon neutrality goal.” EO B-55-18, § 3. The most recent Scoping Plan adopted by CARB sets forth the strategies the state will implement to achieve the 2030 emissions reduction target–40% below 1990 levels–and put the state on the trajectory towards achieving the 2050 target of reducing emissions to 80% below 1990 levels.

The new goal of carbon neutrality by 2045 could be even more ambitious, requiring not only that emissions be reduced to 80% below 1990 levels by 2050, but that, by no later than 2045, the remaining emissions be offset by equivalent net removals of carbon dioxide (CO₂) from the atmosphere, including through sequestration in forests, soils and other natural landscapes.

Upon adopting the current Scoping Plan last December, CARB’s Board adopted a goal of sequestering and avoiding at least 15-20 million metric tons of CO₂ in the natural and working lands sector by 2030. CARB Resolution 17-46, Dec. 14, 2017, at 9. The Board also ordered CARB staff to reevaluate this goal by no later than September 30, 2018, and to establish a carbon accounting framework and implementation plan for natural and working lands. Id. These efforts are ongoing.

While a study published in the Proceeding of the National Academy of Sciences last year indicates that up to 13.3% of the cumulative reductions needed to meet California’s 2050 target could be achieved from natural and working lands, how one accounts for those reductions and whether a sufficient number will indeed be available to offset all remaining emissions by 2045 is by no means certain. If they fall short, then this new goal could require the state to look to other sectors to take up the slack.

In other words, a goal of net zero emissions by no later than 2045 could require emitting sectors to reduce their emissions even more deeply or sooner than the existing 2050 target, depending upon how the state accounts for land-based sinks of CO₂. This could catalyze stakeholders from emitting sectors to focus more intently on the development of the accounting methods and science needed to demonstrate reductions from natural and working lands, lest emitters be forced to shoulder the burden of any shortfall. At the very least, it assures that land-based reductions share the spotlight with SB 100’s goal of 100% zero-carbon energy at this week’s Global Climate Action Summit.