U.S. Biogas Production is Key to Meeting COP26 Global Methane Pledge Goals

By John Hanselman, Founder and Chief Strategy Officer, Vanguard Renewables

Special to The Digest

At COP26, the United Nations climate change summit, top leaders from around the world (save a few) came together to collaborate on solutions for keeping the planet’s temperature from rising above 1.5 degrees Celsius compared to pre-industrial levels. They agreed that the most pressing matter is to mitigate emissions of the harmful greenhouse gas (GHG) methane, which, due to its high potency and short life expectancy in the atmosphere relative to other GHGs, would yield a tremendously positive impact if immediately sequestered.

Methane has about 30 times the global warming potential over a century compared to carbon dioxide and there are viable solutions in the market today that can help mitigate its release. But monetary incentives sometimes get in the way of methane sequestration methods becoming more widespread; it is often necessary for governments to make sure economic opportunities for growth are in place. Perhaps the most substantial outcome from COP26 was a coalition of 100 countries, including the U.S. and EU, which launched the Global Methane Pledge, an agreement compelling participating countries to decrease methane emissions by 30% from 2020 levels by 2030.

Assuming current trends continue, methane emissions are projected to increase year-over-year until 2040 at the earliest. The countries signed onto the pledge comprise nearly 50% of global anthropogenic methane emissions and over two-thirds of the global GDP. If the measures in the Pledge are implemented as written, they are expected to prevent 0.2˚C of global temperature warming by 2050.

Reducing human-induced methane emissions is an effective strategy to rapidly reduce the rate of warming and benefit the public health of these nations. But what does decreasing methane emissions look like on the ground? What are the common causes of methane emissions, and are there existing solutions ready to tackle the challenge?

Where Do Methane Emissions Come From?

With a defined emission reduction goal, individual countries must now address the sources of their methane emissions. The face of the climate mitigation enemy is the fossil fuel sector as it accounts for 35 to 40 percent of annual methane emissions from oil, gas, and coal extraction and transportation. While fossil fuel contribution to global warming is significant, two other sources that account for approximately 60 percent of the total global emissions are often overlooked: waste and agriculture. Methane emissions from waste and agricultural product decomposition account for 20 and 40 percent of the total, respectively.

Waste Methane

• Methane derived from waste is produced when bacteria decompose organic material in food waste or sewage. Food waste can range from inedible byproducts of food production to unconsumed food.
• Population growth and income growth in regions with underdeveloped waste management systems are expected to result in an increase of about 13 Mt/yr of additional methane emissions, according to the Climate and Clean Air Coalition.

Agriculture Methane

• Agricultural methane is derived from cattle, dairy, and crop production. What is it? Manure, what’s leftover in the fields after harvest?
• An increase in emissions from enteric fermentation and manure management of around 6 Mt/yr is projected from increased demand for protein because of population growth.

Because food and farm waste are the major contributors to methane emissions, and are projected to increase, we need to focus on solutions to sequester the natural expulsion of methane from agriculture and waste decomposition. The most obvious and promising solution I see involves the production of biogas and renewable natural gas (RNG). This solution can be supported through Biden’s Rural America plan in which American agriculture will achieve net-zero emissions, developing bio-based manufacturing, ethanol, and the next generation of biofuels.

Anaerobic Digestion is a Viable Methane Sequestration Method

According to the EPA, 63.31 million tons of food waste were generated in the United States in 2018. When food waste decomposes in a landfill, it releases methane into the atmosphere. Anaerobic codigestion of manure and food waste harnesses the methane released from food waste and converts it into a carbon-negative fuel source, RNG. Instead of allowing the decomposition of waste materials and agricultural byproducts to release methane into the atmosphere, this natural process can transform into something great in an anaerobic digester. Anaerobic digesters are large tanks or lagoons with attached gas-capturing mechanisms that harness biogas, composed of methane and carbon dioxide, that is expelled from decomposing cow manure and food and beverage waste. This process results in two products: biogas and liquid digestate. The captured biogas is then converted into RNG that can power the electrical grid. Liquid digestate provides a nutrient-rich fertilizer which enhances crop growth. Biogas and digestate capture through anaerobic digestion supports a circular pathway and economy, turning a negative into a positive force. Because anaerobic digestion process sequesters methane from emissions that normally come from the decomposition of manure and food waste, RNG yields a better GHG reduction profile than solar or wind.

Ramping Up Anaerobic Digestion Production is Key

To adhere to the Pledge, the signatories must begin looking for alternative methods to curb their methane emissions. Methane sequestration methods such as anaerobic digestion offer a viable, fast-acting solution. Simultaneously, the natural gas industry is under pressure from regulatory and environmental communities to reduce its carbon intensity from brown gas harvesting practices and using non-renewable resources. This is fostering a significant demand for RNG to replace a percentage of current pipeline gas that emits dangerous GHGs.

Despite the daunting prospect of suppressing global warming, our current precarious state presents us with an incredible opportunity to enact sustainable change. At Vanguard Renewables, we are doing just that. Vanguard Renewables is an organic waste to renewable energy company with a network of operating farm-based anaerobic digester facilities that convert organic waste and dairy manure into carbon negative RNG. We operate six Farm Powered anaerobic digesters in the northeastern United States and are expanding our footprint nationwide with over 100 anaerobic digesters by 2025.

The methane emission reduction goals targeted by the Methane Pledge require anaerobic codigestion of manure and food waste. We need to ramp up anaerobic digestion across the country; the World Biogas Association (WBA) reaffirms that a prompt deployment of anaerobic digestion technology can help deliver on the Pledge’s commitment. Biogas is the future of renewable energy, and anaerobic digestion will lead the charge.

About the Author

John Hanselman is Founder and Chief Strategy Officer of Vanguard Renewables — the U.S. leader in farm-based organics to renewable energy. John launched Vanguard Renewables in 2014 to connect farm-based anaerobic digestion to agricultural resilience and produce renewable energy. His work includes finding a decarbonization pathway for the food and beverage industry by enabling the repurposing of unavoidable manufacturing and supply chain waste into renewable natural gas. John’s strength is bringing together partners in the decarbonization journey and Vanguard has strategic partnerships with Dairy Farmers of America and Dominion Energy, among others. In 2020, Vanguard Renewables launched the Farm Powered Strategic Alliance alongside founding members Dairy Farmers of America, Unilever, and Starbucks, a pre-competitive movement to explore decarbonization strategies, to recycle unavoidable food waste at farm-based anaerobic digesters, and convert a portion of thermal load to renewable natural gas. Vanguard currently has six operating farm-based anaerobic digesters, seven under construction, and 10 in development across the U.S. The company plans to expand its program to more than 100 operating anaerobic digesters over the next five years.