A U.S. economy-wide methane target: essential, achievable, affordable

The Biden administration is preparing to announce a new U.S. greenhouse gas emissions target for 2030 under the Paris Agreement — a pledge known as a Nationally Determined Contribution, or NDC — in advance of this year’s United Nations climate talks. Given the last four years of U.S. climate inaction and denial, it is important that the U.S. put forward an ambitious yet credible target and restore its position as a global leader on climate.

Although many countries pledge a single headline target that includes all greenhouse gas emissions, we believe that a complementary methane target is an essential addition that will considerably benefit the climate. Although it would include methane, a combined target is not sufficient to ensure that immediate and strong actions are taken to reduce methane emissions at the extent warranted.

A combined target is not sufficient because:

1. Methane plays a major role in the rate of warming that is not adequately accounted for in the internationally agreed-upon metrics for greenhouse gas reporting (GWP100), such that only adhering to a combined target will undervalue the amount of methane that should be reduced to slow down warming; and
2. These flawed metrics combined with a tendency for anything not specifically delineated to get lost in the mix mean that maximum methane reductions are unlikely to occur, thus missing an important and rare opportunity to avert major damages to societies and ecosystems.

At least 25% of the warming we are experiencing today is caused by human-made methane emissions (nearly 10% of this is from the U.S. alone). And because methane only lasts in the atmosphere for around a decade, any reductions will have a near-immediate impact in slowing down warming.

Reducing these emissions is the biggest, fastest opportunity we have to slow the rate of warming (even as we continue to reduce carbon emissions as quickly as possible).

What a methane target would look like

A new EDF report calls for an explicit commitment to reduce methane emissions economy-wide by 40% below 2005 levels by 2030 as a component of the new NDC. This level of ambition is consistent with existing targets, such as those proposed and adopted by the State of California (SB 1383) and the U.S. Climate Alliance.

Based on a review of the latest science, economics, and technology, methane reductions on this scale are achievable and often yield a net cost savings, and the pathways are comparatively straightforward.

The methane target would act in parallel with the total net GHG target, of which the EDF report calls for a bold new commitment to reduce total net greenhouse gas (GHG) emissions at least 50% below 2005 levels by 2030 — a target that several analyses show is ambitious yet achievable. A complementary, separate methane target will encourage reductions in methane emissions alongside important actions to reduce carbon dioxide emissions. (The methane reductions would also count towards the total net zero GHG target.)

How a 40% methane cut by 2030 is achievable

Five sectors are responsible for over 90% of current U.S. methane emissions: oil and gas (46%), enteric fermentation (animal digestion; 21%), landfills (13%), coal mining (7%), and manure management (7%) [emissions estimates from EPA 2020 for all sectors but oil and gas; oil and gas estimates from EDF modeling].

There are proven technical, regulatory, and management strategies available in each of these sectors that can lower emissions significantly. At the same time, the decarbonization of the energy system happening in parallel to achieve the total GHG target will further drive down methane emissions by lowering the demand for coal and natural gas.

Key mitigation opportunities by sector include:

Oil and gas: Reducing emissions from the oil and gas sector is by far the most impactful, cost-effective and technologically feasible opportunity we have to achieve this target. Emissions can be halved at no net cost just by applying currently existing best-practice regulations to all localities. Abatement can be further increased by deploying the full set of technically feasible options. Key steps include replacing existing equipment like pneumatic pumps with low-emissions alternatives; installing additional devices like vapor recovery units; and instituting more frequent leak detection and repair. A growing surge in new remote sensing data will make it faster and easier to identify emissions across far-flung oil and gas operations (and to tally reduction progress).

Methane emissions will also be reduced if major oil and gas companies meet — or perhaps strengthen — their current commitments to reduce upstream methane emissions from upstream operations to a leak rate of 0.2% or less (current upstream U.S. leak rates are estimated at around 2%).

Enteric fermentation: Cutting-edge feed additives proven to reduce methane emissions from cattle are moving through approval processes, and could be available in the U.S. within the next few years. Other options to reduce emissions from livestock include selective breeding, feed processing and ration changes, and improved health and productivity.

Landfills: While many U.S. landfills already employ technologies to capture methane emissions, studies suggest that the efficiencies can be greatly improved. Further, many facilities do not capture gases before the landfill is closed, but it’s when facilities are operating that methane emissions are highest. Emissions can also be reduced with improvements to capture technologies, as well as from parallel goals to increase recycling rates, reduce food waste and divert yard cuttings.

Coal mining: More than half of emissions from U.S. coal mining can be eliminated with existing technologies (and that’s without accounting for decarbonization of the energy sector). Coal production in the U.S. was already almost 50% lower in 2020 than it was in 2005. Cleaning up the U.S. power supply to meet a 50% total GHG target means that coal will largely disappear from the fuels used to generate electricity, further reducing methane emissions from mining.

Manure management: Today, large-scale agricultural operations store vast amounts of animal manure in lagoons or large storage pits. The resulting emissions can be reduced by covering those sites and capturing the methane. Cover or digester systems across the U.S. sell renewable biofuel to local utilities and are incentivized by grant programs in various states, as well as by the Low Carbon Fuel Standard and the cap-and-trade program in California.

Essential, achievable, and affordable 

Supplementing the U.S. NDC with a distinct methane target will encourage methane mitigation measures to be scaled up and immediately deployed. While some sectors are easier to address than others, the target can be reached via multiple pathways. Some sectors may ultimately overperform expectations while others underperform. An analysis of available cost information reveals that in aggregate, more than half of the emissions reductions needed to reach a 40% target can be pursued at modest cost.

Acting now to reduce methane emissions will have immediate benefits to the climate that reductions in carbon dioxide cannot provide on their own. Simultaneously reducing emissions in carbon dioxide and methane is our best chance for limiting warming and the associated damages in the next decade and over the next century. And this is critical not just on a national scale, but on a global scale. A U.S. economy-wide methane target will raise ambition and awareness of the importance for other countries to follow suit.