Waste not, want not: How methane biogases can help us reach our climate goals 

The Biden administration is cracking down on methane emissions from oil and gas operations.  

Officially, they account for 28 percent of U.S. methane emissions, though a new study shows their methane leaks are even worse than we thought. But we also need deep cuts in emissions from other major methane sources, including agriculture (currently 34 percent of U.S. methane emissions and rising, as EPA’s latest greenhouse gas inventory notes) and landfills (16 percent of U.S. methane emissions, according to EPA, though new data indicates landfills emit 40 percent more methane than previously reported). 

Slashing methane is urgent because it’s a “climate super pollutant” — 87 times more potent than carbon dioxide over 20 years. It has caused about a third of modern warming, and record-high atmospheric methane correlates closely with 2023’s record high temperatures. Cutting it is the most powerful lever we have for reducing warming in the decades ahead. 

In May, EPA’s New Source Performance Standards for oil and gas production start phasing in. By 2029, they will eliminate 130 million metric tons of methane, or 86 percent of annual methane emissions from oil and gas production (compared to 2020). This year, oil and gas operations will also start paying steep fees for annual methane emissions above 25,000 tons, an Inflation Reduction Act provision which should hasten compliance.  

Assuming lawsuits challenging these measures fail and they get fully implemented, at best they cut overall U.S. methane emissions 17.5 percent. That’s important, but gets us little more than halfway to the goal of cutting methane emissions 30 percent by 2030 (“30×30” for short), considered the minimum required to keep warming within 1.5 degrees Celsius.  

The Global Methane Pledge, which President Biden and European Union leaders spearheaded and 155 countries signed, commits to 30×30. But pledging is one thing, and detailed, adequately funded plans, regulations and laws to fulfill the pledge are something else. Those now on the table might get us to 20 percent reductions globally by 2030, not 30 percent.  

The question is, how can the U.S. meet its own 30×30 goal? If its new oil and gas measures cut methane emissions 17.5 percent by 2030, where will the other 12.5 percent come from? 

Not from phasing out oil and gas. Between data centers powering AI and crypto mining, electric vehicle charging, and ambitions to “electrify everything,” electricity demand is accelerating. To meet it, we’ll need to maintain oil and gas generation well past 2030, while tightening methane leaks and adding renewables as fast as we can.  

But wind and solar can’t get us to 30×30 either. Even the most optimistic scenarios for building them out fall short of 2030 emissions goals. They are lagging behind rising electricity demand, so utilities sometimes resort to extending the lives of carbon- and methane-intensive coal-fired plants. 

Nuclear isn’t the answer, either. It doesn’t emit methane, but it’s fraught with economic and safety problems and can’t help reach 30×30 because conventional nuclear plants take between 10 and 20 years to build, and small modular reactors won’t materialize before 2030 at best. 

But there is one scalable option that could get us to 30×30: tapping America’s massive organic waste streams as a renewable energy resource.  

Food waste and farm manure can be processed in airless tanks called anaerobic digesters (ADs), which capture the methane biogases emitted as they decompose. Instead of letting them escape into the atmosphere and cause more warming, these biogases can be captured and burned for on-site heat and power. That emits CO2, but it’s a big net gain for the climate compared to emitting methane. Alternatively, the biogases can be refined into pipeline-grade renewable natural gas, the lowest-carbon fuel available. 

Renewable natural gas from ADs is often net carbon-negative over its lifecycle, since producing it traps more greenhouse gases than are emitted when it is burned. It can fire power plants, fuel vehicles and do anything else fossil natural gas does. It can also displace other carbon- and methane-intensive fossil fuels, including up to 25 percent of current U.S. diesel road fuel use.  

The AD strategy diverts food waste from landfills, eliminating the cause of 58 percent of landfill methane emissions. It converts methane-intensive dairy and swine manure to renewable energy, bio-fertilizer — and income for farmers. 

All this adds up to deep methane emissions cuts. According to a new study by the NGO Energy Vision, if we built 4,700 new ADs to process half of U.S. food waste (the other half is edible and should be redistributed) plus agricultural manure, it would lower overall U.S. methane emissions 13.6 percent.  

This would be fast and relatively inexpensive to achieve, taking two to six years per project and costing a total of $74.2 billion, the study finds. Private investment could be supplemented by $5 billion in federal grants plus other federal financing under the Inflation Reduction Act. Compare that to Georgia’s Vogtle Unit 3, a single nuclear reactor which took 17 years and cost $35 billion to build. 

Adding the 13.6 percent cut in U.S. methane emissions from a rapid AD buildout to the 17.5 percent cut from new oil and gas measures gets us the rest of the way to 30×30, and then some. While other approaches like composting or methane-eating microbes can also help reduce methane emissions, ADs are proven and scalable now and offer the biggest bang for the buck. U.S. organic waste is a huge climate liability if left unaddressed; it’s also a major renewable energy resource that remains largely untapped. Scaling up ADs can change that. 

Matt Tomich is president of the non-profit organization Energy Vision.