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The latest United States Environmental Protection Agency (EPA) greenhouse gas data reaffirms the role of factory farms in driving up the agriculture sector’s emissions. In particular, methane emissions from factory farms continue to rise, raising questions about the Biden administration’s ability to meet its agriculture goals under the Global Methane Pledge.

The new EPA data is relevant to climate targets set by the Biden administration. In rejoining the Paris Climate Agreement, the U.S. committed to reduce GHGs by 50% of 2005 levels by 2030. The new data shows that overall U.S. emissions have declined by 21.5% since 2005. It is possible emissions will rise again because the unique conditions during the pandemic year of 2020 that resulted in an overall 10 % decline in emissions from 2019.

At the Glasgow Climate Summit, the Biden administration committed to the Global Methane Pledge to reduce methane emissions by 30% (of 2020 levels) by 2030. Methane is a potent, short-lived greenhouse gas. While carbon dioxide emissions can remain in the atmosphere for 100 years or more, methane emissions cycle out after 12 years. Sharply reducing methane emissions now can more immediately slow climate change and buy time as the world reduces carbon dioxide emissions. The new EPA data sets an initial 2020 baseline for U.S. methane emissions reductions by 2030.  

The EPA data, covering emissions from 1990-2020, shows declines in most sectors. Agriculture is an exception, where emissions have risen 7.8% since 1990, now accounting for 11.4% of emissions when including on-farm energy use. More specifically, there are worrying trends on agriculture’s methane emissions. While overall methane emissions have declined 16.6% since 1990, agriculture-related methane emissions, deriving primarily from enteric fermentation in ruminants (mostly beef and dairy cattle) rose by 7.2% since 1990. And methane emissions increased a whopping 71% from manure management. The EPA tied the growth of manure-related methane and nitrous oxide emissions since 1990 to the factory farm system of hog (44% increase in methane) and dairy (122% increase in methane) production that liquify their manure.

The EPA explained, “When livestock manure is stored or treated in systems that promote anaerobic conditions (e.g., as a liquid/slurry in lagoons, ponds, tanks, or pits), the decomposition of the volatile solids component in the manure tends to produce CH4 (methane). When manure is handled as a solid (e.g., in stacks or drylots) or deposited on pasture, range, or paddock lands, it tends to decompose aerobically and produce CO2 and little or no CH4.” (p. 425)

“In many cases, manure management systems with the most substantial methane emissions are those associated with confined animal management operations where manure is handled in liquid-based systems… The shift toward larger dairy cattle and swine facilities since 1990 has translated into an increasing use of liquid manure management systems, which have higher potential CH4 emissions than dry systems,” concludes the EPA.

Agriculture’s other primary GHG source is the potent nitrous oxide (299 times the potency of carbon dioxide over a 100-year period). The largest source of U.S. nitrous oxide emissions is through agriculture fertilizer application, often for animal feed crops like corn, accounting for 74.3%. While fertilizer related nitrous oxide emissions have remained relatively flat, those linked to the liquified manure systems of factory farms have risen 41.2%, according to the EPA.

The Biden administration plan to meet the Global Methane Pledge includes an agriculture strategy devoted almost entirely to subsidizing the expanded use of factory farm gas digestors on large-scale operations. The digestors would capture the methane (the nitrous oxide emissions remain) from these operations and send it to natural gas pipelines often as part of partnerships with companies like Shell or Chevron. The digestors are highly controversial in rural communities because the manure remains and is spread on neighboring land causing water and air pollution. There are growing indications that a factory farm gas buildout creates perverse incentives for operations to expand their animals and manure production, leading to further consolidation in the dairy industry. The creation of factory farm gas and associated pipelines poses additional risks for rural residents. Methane is highly flammable and explosive, and exposure can cause short and long-term health risks.

The Biden administration’s commitment to the U.N. Paris Climate agreement and the Global Methane Pledge will need to account for rising emissions linked to factory farm system. This system is propped up by Farm Bill programs that incentivize cheap (often below cost) animal feed, and different types of direct subsidies and government backed loans. Factory farms also benefit from a regulatory system that has turned a blind eye toward the industry’s water and air pollution for many years.

Last year, IATP and other environmental justice and climate groups petitioned the EPA to begin to regulate methane emissions from the largest hog and dairy operations under the Clean Air Act. The EPA has yet to act on the petition. Regulatory action needs to be coupled with a reformed 2023 Farm Bill to support farmers raising animals in more agroecological systems and those transitioning out of the factory farm system. These steps would set a clear and predictable path for reaching the 2030 Methane Pledge target and contribute to the country’s Paris Climate agreement commitments.