Delta islands farming produces excessive CO2 pollution
Sometimes the solution to a problem is staring us in the face. But we develop perspectives that blind us from seeing it.
Such is the case with the protracted debate over the sinking islands used for farming in the Sacramento- San Joaquin Delta and the related issue of how to protect the Delta and the state’s water supplies from the inevitable failure of the levees that protect the islands.
Due to oxidation of the organic peat soils of the Delta, farming on the islands has been one of the largest single sources of carbon emissions in California. We need to open our eyes to an opportunity that climate change experts say can significantly reduce carbon emissions, protect water supplies, improve Delta sustainability, and help restore the Delta’s fragile ecosystem.
It is well- documented that longstanding farming practices on the Delta islands generate massive concentrations of carbon dioxide that drive climate change. UC Davis geologist and Delta expert Dr. Jeffrey Mount has joked that “If this was a smokestack, you’d regulate it.”
As farmers till the peat soils, the carbon in it combines with oxygen and is released as the greenhouse gas carbon dioxide. The result: an estimated 1 to 2 million tons of CO2 released into the atmosphere every year. Eliminating these emissions would be the equivalent of removing 300,000 vehicles from California’s roads.
Sadly, farming on these sinking islands is unsustainable. Some of the Delta islands behind the more than 1,100 miles of levees are up to 30 feet below sea level and continue to sink every day.
Due to this land subsidence, early levee construction techniques and rising ocean lev- els, the levees are vulnerable to large earthquakes from faults that are close to the Delta. Like land subsidence, sea level rise may be slow-moving, but its consequences will be devastating. Sea level rise is happening faster than previously expected and could overwhelm the levees unless we act now.
This is urgent because if the ocean imperils the levees, it will be impossible to export water to the Bay Area, the Central Valley and Southern California due to salty water in the Delta. The Delta is 20 percent of the entire state’s water supply and up to 100 percent in some regions. Losing that supply is unimaginable.
The Delta Conservancy, the state agency created to help re- store the Delta, recently won approval for a new carbon banking method that would allow selling carbon credits to help reduce the state’s carbon emissions.
Delta island farmers could begin an inevitable transition of their land by ceasing harmful farming practices and, in accordance with the new standards, selling carbon capture and reduction in much the same way the forest industry has successfully accomplished.
If wetlands vegetation were planted and maintained, accumulation of organic material could begin to bring the islands back up toward sea level, improving ecosystem opportunities and reducing water supply risks.
The benefit for taxpayers could come from a reduced need to continue to heavily subsidize levee maintenance for these private farms. Private sector purchases of carbon credits would reduce the state’s need to spend money to meet our greenhouse gas emission reduction goals.
Experts estimate the payoff in annual carbon reductions from this strategy could be upwards of 5 to 6 tons of CO2 per acre of farmland, or more than a million tons of carbon reduction per year for about 200,000 acres converted.
Let’s help the Delta farmers help themselves, and help us all with early implementation of the new Delta carbon trading method.
Due to oxidation of the organic peat soils of the Delta, farming on the islands has been one of the largest single sources of carbon emissions in California.