Marin Carbon Project

Can soil carbon sequestration help slow climate change?

The Intergovernmental Panel on Climate Change, comprised of over 2000 scientific, policy, and economics experts, found that even if we stopped all greenhouse gas (GHG) emissions today, atmospheric CO₂ would still be at 1985 levels 100 years from now. [IPCC, 2007]. Reducing emissions, though crucial, will not be sufficient to stop global warming. Additional strategies are needed. One that holds promise is carbon sequestration in soils, a process that takes CO₂ from the atmosphere and stores it in soils in a form that does not contribute to the greenhouse effect.

How does soil carbon sequestration work?

Plants actively take CO₂ from the atmosphere during the process of photosynthesis and convert it to tissues (called biomass). When plant biomass dies it is deposited on or in the soil where microbes, primarily bacteria and fungi, begin the process of decomposition. During decomposition some of the dead plant material is converted back to CO₂ via microbial respiration and some becomes part of the soil, termed soil organic matter. Soil organic matter can be stored for short (<1 year) or long (>100,000 years) time periods. The length of time it is stored depends upon the chemical make up of the plant material, the soil chemical and physical properties, and the climate. Sequestering carbon in the soil through this natural process helps to slow global warming.

Scientists and government agencies agree that soil carbon sequestration is an important strategy for reducing global warming:

“Enhancing the natural processes that remove CO₂ from the atmosphere is thought to be the most cost-effective means of reducing atmospheric levels of CO₂.” [US Department of Energy]

Globally, grasslands are likely to have the potential to sequester more soil carbon per acre than forest. “Soil represents the largest carbon sink over which we have control. Improvements in soil carbon levels could be made in all rural areas, whereas the regions suited to carbon sequestration in plantation timber are limited.” [Jones, 2007]

Increasing soil organic matter in agricultural and rangeland soils by 0.15% per year can offset increases in atmospheric CO₂. This can be maintained for 25 to 50 years [Lal, 2007], buying time to create the bridge to new technologies and super efficiencies.

Is it possible to optimize these relationships, to maximize the rate and amount of carbon sequestration? If so, how can that be achieved?

The Marin Carbon Project was formed to address these questions.

Marin Carbon Project

Contact: info@marincarbonproject.org