I. INTRODUCTION II. THE BASICS OF AB 32 AND ITS CAP AND TRADE PROGRAM III. THE BASICS OF OFFSET PROGRAMS IV. AGRICULTURAL OPPORTUNITIES FOR OFFSET PROGRAMS A. Decreasing Livestock Emissions Through Manure Management B. Decreasing Cropland Emissions Through Agricultural Soil Carbon Sequestration 1. Agricultural Soil's Ability to Sequester Carbon 2. Existing and Proposed Agricultural Soil Carbon Sequestration Offset Programs 3. A Future Agricultural Soil Carbon Sequestration Offset Program for California?... V. THE DIFFICULTIES WITH SOIL CARBON SEQUESTRATION OFFSET PROGRAMS A. Difficulties in Quantifiability, Permanency, and Additionality B. Increased Herbicide Use Replaces Tilling When Sequestering Carbon VI. REDUCING UNCERTAINTY AND HARM IN AGRICULTURAL SOIL CARBON SEQUESTRATION OFFSET PROGRAMS THROUGH AN ECOSYSTEM APPROACH A. Quantifying Carbon Sequestered in Agricultural Soil B. Additionality of the Offset Project C. Understanding and Decreasing Herbicide Use VII. WEAKNESSES WITH CASE-BY-CASE ANALYSES WITHIN THE ECOSYSTEM APPROACH VIII. CONCLUSION
In 2006, California signed the Global Warming Solutions Act of 2006, or Assembly Bill 32 (AB 32), into law. (1) AB 32 aims to reduce California's greenhouse gas emissions to 1990 levels by 2020 through a variety of regulations promulgated by the California Air Resources Board (CARB) including a cap and trade program. (2) The cap and trade program already includes four offset programs that give capped entities the opportunity to meet their emissions limitations in the most economically efficient way available. Whereas the level of emissions in a compliance obligation that may be accounted for through an offset program is capped at 8%, the number of existing offset programs that may be used to reach this 8% can be increased to include additional offset programs. (3) Adding offset programs may be attractive to covered industries and government alike because offset programs allow covered entities to determine what the most economically efficient way to comply with emission limitations is for that specific entity while still complying with the overall program emissions cap.
CARB's implementing regulations for AB 32 do not address California's large agriculture sector as directly as other sectors, as its dominant strategy to reduce agricultural emissions is to encourage dairies to voluntarily install manure digesters. (4) However, California's agricultural sector, primarily manure and cropland management, provides ample opportunity for offset programs. It is a sector with significant greenhouse gas emissions and sinks that is not otherwise regulated by the cap and trade program. one offset program already takes advantage of this opportunity by issuing offset credits for capturing and destroying methane from dairies and swine farms using particular manure management systems. (5) Another opportunity for an agricultural-related offset program arises from the ability of agricultural soil to sequester carbon. Soil is an important sink for carbon, and the United Nations Food and Agriculture Organization estimates that soils can sequester over 10% of the anthropogenic carbon emissions in twenty-five years. (6) Whereas some cap and trade programs, such as the European Union's European Trading System and the first compliance period of the Kyoto Protocol, do not recognize offset credits from most carbon sequestration offset programs because the emission reductions are difficult to measure, verify, and track, future sequestration programs under AB 32's cap and trade program are possible. (7) AB 32's cap and trade program already includes two carbon sequestration offset programs, both stemming from the power of trees to sequester carbon, and other types of sequestration programs are not prohibited in the regulations. (8)
Consequently, adopting an agricultural soil carbon sequestration offset program seems like a possible option for a future offset program under AB 32. …