The Biological Carbon Sequestration Capacity of Forests and Soils: Implications for Climate Change Mitigation Reductions in California

Biological carbon sequestration capacity refers to the maximum amount of carbon vegetation and soils could store from carbon dioxide (CO₂). CO₂ levels in the atmosphere are rising due to human activities such as burning fossil fuels for transportation. In California significant climate change policies are being tested. For example AB32, or The Global Warming Solutions Act (2006), quantified annual greenhouse gas (GHG) reduction targets and established other mitigation strategies. In addition to annual GHG rates, estimates of cumulative carbon sequestration capacity and existing carbon storage are important for quantifying CO₂ reduction options. Here I explore how datasets of forest biomass, soils, and potential vegetation can be used to estimate cumulative measures of biological carbon storage and biological carbon sequestration capacity in California. I will compare these estimates to other mitigation options and to cumulative AB 32 emission reduction targets. My analysis is based on data available from state inventories and reports, and from maps and assessments published by the U.S. Geological Survey. I anticipate that my estimates of California’s biological carbon sequestration capacity will demonstrate the importance of understanding cumulative measures over time, in addition to annual rates. I will also show how trade-offs are critical when considering carbon enhancement projects. For example, converting farmland back into wetlands, which store large amounts of carbon, decreases crop production but increases carbon storage. Estimates of multi-year cumulative biological carbon storage and sequestration capacity, and full consideration of trade-offs and other mitigation options are needed in order to craft effective CO₂ reduction strategies.