This proposed bill did not pass, but CARB is in the process of constructing a webpage that will provide information on proposed offset programs, and the agency affirmatively notes that it will be considering additional offset programs as a part of future rule making activities.Thus, an agricultural soil carbon sequestration offset program may not be far from being proposed and considered as a possible offset program under California’s cap and trade program.Ensuring that emission reductions are quantifiable, permanent, and additional are important considerations for any type of offset program but are particularly difficult in relation to agricultural soil carbon sequestration offset programs. Quantifiability and permanency are especially central concerns about offset programs, and it has been suggested that agricultural soil carbon sequestration plays such a minimal role in major carbon markets because soil carbon is considered difficult to measure, verify, and track.Deciding how to allocate offset credits can be challenging in any carbon sequestration program because it is difficult to accurately quantify how much carbon has really been sequestered.Soil carbon sequestration depends on a complicated living system that is constantly changing and not easy to directly quantify. A variety of factors determine how much carbon a unit of soil can sequester, including seasonal variations, weather, precipitation, plant species present, and the variation in soil type and quality.This problem does not arise in offset programs that decrease emissions from point sources, such as smokestacks or manure lagoons,rolling benches for greenhouse where measurement is more concentrated and accurate methods of measurement are established and verifiable. For example, a manure lagoon equipped with a BCS can use a meter to determine methane emissions from the entire lagoon. Adding to the complication of quantifiability, some studies dispute whether conservation tillage practices actually sequester carbon at all.
The goal of permanency is problematic in agricultural soil carbon sequestration programs because the carbon reduction is easily reversible.When carbon is sequestered in soil, it can be re-released into the atmosphere from a disturbance such as increased intensity of tilling, wind or water erosion, or a natural disaster such as an earthquake, fire, or disease outbreak.One agricultural soil carbon sequestration offset program incorporates a 60% discount into its program to account for the uncertainty of permanency.Compare this to destroying a unit of methane with a BCS or reducing a unit of carbon emissions from a smokestack by installing new technology. When that methane or carbon unit is destroyed or never created, that reduction is not reversible because it never existed.Simple disturbances can cause the loss of some or all of the carbon that was stored in the soil and essentially negate any climate change benefit.Additionality is also at issue with agricultural soil carbon sequestration offset programs because cropland conservation practices such as no till and conservation tillage are already widely used in at least some parts of the United States due to incentives programs set up by the USDA starting in the 1960s and 1970s.The USDA study on cropland conservation practices in the Missouri River Basin indicates that within the 95 million acres of cropland studied between 2003 and 2006, 46% of the cropland met no-till criteria and 97% of the cropland “had evidence of some kind of reduced tillage on at least one crop in rotation.”Considering that cropland conservation practices seem to be common in at least some parts of the country, it may be difficult to tell if any given offset project under an agricultural soil carbon sequestration offset program would have occurred anyway in a business-as-usual scenario for purposes of determining additionality.The checkpoints for offset programs—that the offset credits generated are quantifiable, real, permanent, and additional—do not explicitly include an analysis of the trade offs or incidental effects of an offset program. However, in agricultural soil carbon sequestration offset programs, the considerations of incidental effects caused by the offset program should be a critical checkpoint to consider.
Some of the conservation practices that most effectively sequester carbon in agricultural soil can present trade offs that bring new problems for farmers that must be fixed through alternative means. Primarily, tilling decreases weed growth, so farmers who infrequently or never till typically use more herbicide to keep weeds out of their field.Farmers using the other sequestration practices encouraged under soil carbon sequestration programs besides no-till and conservation tillage are also reported as using much larger quantities of herbicide. For example, the Kenya Agricultural Carbon Project does not address the use of herbicides, and the World Bank reported that herbicides are heavily used on farms that are involved with the project.An environmental and social monitor for a soil carbon sequestration program reported that “the herbicides are applied . . . without due regard to environmental consequences.”At least one assessment reported contrary findings, that less herbicide was used when conservation practices were employed.However, this assessment utilized many types of conservation practices including improved pesticide management practices, which could explain the decrease in herbicide use in this study. Increased herbicide use can be detrimental for reasons including environmental harm, pollutant emissions, and human health. Herbicides can migrate into the surrounding environment through soil, air, and waterways.The resulting chemical residues can negatively affect the natural surroundings, as any chemical might.The effects would depend largely on the toxicity of the chemicals used in the herbicide, the quantity used and leached, and the sensitivity of the surrounding environment. Additionally, harmful air pollutants, including greenhouse gases, are released when using herbicides.Herbicides release a large amount of nitrous oxide, a powerful pollutant with an estimated 298 times the global warming potential of carbon dioxide.This can be seen as similar to the problem of copollutants. Co-pollutants are pollutants that are released simultaneously and from the same source as the greenhouse gas or pollutant at issue. Increasing emissions of the pollutant at issue will often increase co-pollutant emissions, which can be more localized and harmful in smaller quantities. Similarly, increasing herbicide use will increase nitrous oxide emissions that would not have otherwise occurred if not for increased herbicide use. Thus, even if an agricultural soil carbon sequestration offset program is measured to be carbon neutral, it may unintentionally provide an avenue for increased nitrous oxide emissions and harm to the environment. Another incidental effect of increased herbicide use is that more chemicals will be put onto our food products and affect human uses of soil, water, and air.Herbicides have been linked to serious diseases, such as non-Hodgkin’s lymphoma, soft-tissue sarcoma, and Parkinson’s disease.Due to these health risks, some countries have started to mandate that farmers reduce the amount of herbicide used on their crops due to the harmful human health effects of herbicides.
These circumstances have led some to sharply oppose the increased use of herbicide. If CARB considers including an agricultural soil carbon sequestration offset program in AB 32’s repertoire of offset programs,cannabis grow systems the issues of quantifiability, permanency, additionality, and incidental effects of the offset projects should be addressed. Implementing a new agricultural soil carbon sequestration offset protocol under AB 32 without considering and compensating for these issues would jeopardize the purpose of AB 32’s cap and trade program and likely inflate AB 32’s carbon market with credits that do not actually represent the additional sequestration of one ton of carbon dioxide or its equivalent.These issues may be most completely and accurately addressed by using an ecosystem approach to design the offset program and to approve and implement the resulting offset projects in a case-by-case manner. An ecosystem management approach acknowledges the inter connectivity of the parts within an ecosystem and sees the environment as a single functioning landscape.This approach recognizes that considering only a single species, pollutant, or practice can be detrimental when it successfully decreases one harm but incidentally increases another harm that may be just as, if not more, harmful to the ecosystem. Accordingly, any increase in herbicide use, and subsequent nitrous oxide emissions, or any other potentially harmful externality would be accounted for in the offset program. Under an ecosystem approach, offset programs would not favor projects or regulations that induce harms of a larger or more detrimental magnitude than the harm which is to be prevented by the program. The need for an ecosystem approach, and the regulating agency’s response to this need, is illustrated by the Endangered Species Act.Certain species are listed and protected under the Endangered Species Act and a federal budget is allocated to preserving those listed species. However, many believe that the environment and society would be better served by protecting and managing ecosystems on a larger scale as opposed to individual species.Recognizing this and similar needs in different areas under their jurisdiction, the U.S. Fish and Wildlife Service published An Ecosystem Approach to Fish and Wildlife Conservation, which includes guidelines the FWS strives to use in order to incorporate the ecosystem approach into their conservation work. The Pacific Islands Forum Fisheries Agency , a group formed to help its Pacific Island members to manage, control, and develop the fisheries within the Exclusive Economic Zones, encourages its countries to utilize an ecosystem approach to manage their fisheries.The FFA’s Ecosystem Approach to Fisheries Management consists of four steps.The first step is to determine the scope of the assessment by clearly identifying what is to be managed.The second step is to identify all the issues to be assessed within five key areas and to agree on the values that are to be achieved for each issue.The third step is to determine which issues should be directly managed.The last step is to determine acceptable performance levels, what management arrangements will achieve these levels, and the review process for assessing performance.During the creation of the offset program, an ecosystem approach could be utilized to determine whether the program should be created at all. If no agricultural soil carbon sequestration offset project could ever in theory have a net benefit when considering all the greenhouse gas sources and sinks and other externalities created by an individual project, then the analysis under an ecosystem approach may indicate that the offset program should not be approved. If the analysis of the offset program under an ecosystem approach indicates that only certain types of projects could result in a net benefit to the environment, the program could be limited to those particular types of projects. The ecosystem approach could also be used to assist in determining on a case-by-case basis whether an agricultural soil carbon sequestration offset project should be approved under the offset program. Because the variables associated with each agricultural soil carbon sequestration project will be different for each project and have the potential to vary greatly, a case-bycase ecosystem approach for the approval process for each project would help decision makers to properly determine whether the offset project is quantifiable, permanent, real, and additional. Which externalities should be included in an ecosystem approach analysis of agricultural soil carbon sequestration projects would be a basis for much disagreement, and would depend on scientific and policy analysis beyond the scope of this Comment. However, at a minimum, the effects of increased herbicide use on the surrounding ecosystem and the increase of nitrous oxide emissions should be included in the analysis, as those are some of the more egregious oversights in certain existing agricultural soil carbon sequestration programs, as discussed in Part V.B. In addition to legitimizing a future offset program and resulting offset projects in general, applying case-by-case and ecosystem approaches have the potential to resolve specific issues regarding quantifiability, additionality, and incidental effects identified in Part V.At least two main methods of quantifying agricultural soil carbon sequestration for the purposes of allocating credits for agricultural soil carbon sequestration offset projects could be envisioned. One is a simpler standards-based approach and the other follows a case-by-case process. Although a case-by-case approach may be impracticable in practice, this example illustrates why a case-by-case approach would be more appropriate and crucial for an agricultural soil carbon sequestration offset program. The standards-based option is to give an offset credit per a certain acreage of land covered by an offset project.That particular acreage of land would, on average, sequester one metric ton of carbon dioxide or carbon dioxide equivalent regardless of individual features of the land.