You are here: Home » News & Events » News » ACR Approves Landmark Carbon Offset Methodology for California Wetland Restoration

ACR Approves Landmark Carbon Offset Methodology for California Wetland Restoration

SACRAMENTO, Calif., April 25, 2017 – Today the American Carbon Registry (ACR), a nonprofit enterprise of Winrock International, announced approval of a new carbon offset methodology to scientifically quantify greenhouse gas (GHG) emissions reductions from the restoration of California deltaic and coastal wetlands. The methodology was developed by a high-profile group of partners — the Sacramento-San Joaquin Delta Conservancy as lead agency and HydroFocus as lead author with technical support from the University of California at Berkeley and Tierra Resources. Funding for the methodology was provided by the Sacramento Municipal Utility District (SMUD), the California Coastal Conservancy, the Metropolitan Water District and California Department of Water Resources (DWR).

The new ACR methodology combines California data and restoration techniques to create a rigorous scientific framework for carbon offset project development. Opportunities are abundant to enhance current land-use practices by restoring wetlands or converting to rice cultivation in the Sacramento-San Joaquin Delta, Suisun Marsh, and California coastal areas. Carbon offsets generated by the projects can be sold to corporations to meet their voluntary emissions-reduction goals. Additional sources of offsets are also being considered by California regulators for eligibility in the state’s Cap-and-Trade Program, under which power plants and oil refineries are mandated to reduce or offset their emissions.

Restoration activities that rebuild subsided lands are critical to long-term ecosystem sustainability, are important to reducing the risk of levy failure and sea level rise, and are a significant source of GHG emissions reductions. said Steve Deverel, President of HydroFocus.

In the Bay-Delta Area, more than 90 percent of historic tidal wetlands disappeared in the last 150 years. Over 2.5 billion cubic meters of organic soils have disappeared since delta islands were first diked and drained for agriculture in the late 1800s, resulting in land subsidence up to 25 feet below sea level. Drained and cultivated organic soils continue to oxidize, subside and emit an estimated 1.5 to 2 million metric tons of CO2-equivalent annually — equal to annual emissions from over 300,000 passenger vehicles.

Research in freshwater emergent wetlands on delta organic soils shows that carbon capture wetlands are the most carbon-rich landscape per acre. The U.S. Geological Survey (USGS), DWR, HydroFocus and the University of California at Berkeley have been studying subsidence and GHG emissions of rice and managed wetlands in the delta since the 1980s and have documented very high rates of primary productivity in wetlands. 

“State and federal funding remains insufficient to address land subsidence that threatens the California water system, and carbon market revenues could help fill the funding gap,” said Campbell Ingram, executive officer of the Sacramento-San Joaquin Delta Conservancy. ”The new ACR methodology provides an incentive to landowners in the Sacramento-San Joaquin Delta, Suisun Marsh, and other historically natural wetland areas in California to convert their most subsided and marginal agricultural lands to wetlands or to produce wetlands crops such as rice, which will stop land subsidence and reverse it over time.”