California’s climate policy paying dairy farmers to capture methane from manure for biogas production is facing criticism. Researchers warn that the state's approach to methane and carbon dioxide emissions undervalues long-term atmospheric impacts, potentially worsening global warming despite short-term gains.
- Methane offsets undervalue long-term carbon dioxide impact
- Program incentivizes biogas but risks net warming increase
- California extended the program beyond 2050 despite criticism
What happened
California designed a climate initiative that pays cattle farmers nationwide to capture methane from manure using anaerobic digesters, converting it into natural gas. This biogas is then sold to fuel producers who obtain Low Carbon Fuel Standard (LCFS) credits to meet emissions regulations. The system has gained widespread adoption due to its lucrative subsidies and the appeal of reducing methane, a potent greenhouse gas.
However, the state’s metric treats methane as 25 times more impactful than carbon dioxide over a 100-year period. This simplification overlooks methane's rapid atmospheric breakdown in a couple of decades, while carbon dioxide lingers, causing cumulative warming over centuries. Consequently, reductions in methane emissions are being offset by increased carbon dioxide emissions, undermining the overall climate benefit.
Why it matters
This discrepancy in carbon accounting distorts the true climate impact of California’s dairy methane program, potentially locking in more long-term global warming despite short-term methane emission reductions. Allowing transportation fuel companies to buy credits from methane-to-natural gas projects may reduce their immediate carbon footprint but effectively permits more persistent carbon dioxide emissions.
Researchers caution that simply exchanging short-lived greenhouse gas reductions for increases in long-lived gases is a flawed approach that can hinder efforts to stabilize global temperatures. The program thus exemplifies broader challenges with carbon offset schemes that misrepresent real-world atmospheric effects and jeopardize climate targets.
What to watch next
Despite mounting criticism, California regulators decided in 2024 to continue parts of the dairy methane credit program beyond 2050, and current proposals could channel millions more dollars to farmers while easing greenhouse gas restrictions on large emitters. Stakeholders will be watching how policy adjustments respond to climate science concerns and whether reforms improve emission accounting accuracy.
In the near term, scrutiny of the state's Low Carbon Fuel Standard and its reliance on offsets will intensify. Monitoring the implementation and environmental outcomes of these programs will be crucial to determining if California can reconcile economic incentives with robust climate action that addresses both short- and long-lived greenhouse gases effectively.