Biogas and Synthetic Gas Not the Solution to Polluting Natural Gas in Today’s U.S. Energy System

SAN FRANCISCO – Neither synthetic gas nor biogas derived from food scraps, animal waste, or woody biomass are viable replacements for America’s consumption of polluting natural gas, according to a report published today by NRDC (Natural Resources Defense Council). These resources may play a small role in reducing climate pollution, but the best alternatives to natural gas (more accurately described as “fossil gas”) are emissions-free energy efficiency and electricity from renewable sources like the sun and wind.

Synthetic gas (which is created using electricity) and biogas are touted by the gas industry as “renewable” substitutes, but they could replace only 3 to 7 percent of today’s U.S. fossil gas use for heating, cooking, and other purposes. These alternatives would be extremely costly (up to 18 times more than fossil gas), still damage human health, and can have negative environmental effects, according to NRDC’s Issue Brief, “A Pipe Dream or Climate Solution? The Opportunities and Limits of Biogas and Synthetic Gas to Replace Fossil Gas.”

“Biogas and synthetic gas do have a small role to play but have far too many limitations to be a primary solution to the significant climate and health impacts from burning so-called ‘natural’ gas,” said NRDC scientist and report author Merrian Borgeson.

“These gas-based alternatives could be used in sectors that are difficult to electrify, such as some industrial processes and long-distance transportation, or at the site where the gas is generated to avoid transporting methane and building new pipelines,” she said. “The vast majority of the solutions to dirty fossil gas will come from transitioning to truly renewable, emissions-free clean electricity if we have any hope of slowing the worsening climate crisis.”

  • Biogas is primarily methane produced from organic sources like food scraps, animal waste, or woody biomass. Biogas resources are limited in supply, and often have significant environmental consequences. Many sources also have more beneficial uses than being converted to methane, the true name for natural gas. NRDC estimates biogas could replace just 2 to 5 percent of today’s fossil gas use.
  • Synthetic gas is methane or hydrogen created using electrical power. It has some potential to scale with the growing supply of renewable electricity, but is still projected to be very expensive in 2040 and 2050. In the Issue Brief, NRDC uses the American Gas Foundation (AGF) estimate that synthetic methane could replace just 1 to 2 percent of current gas use.

The AGF study projects that biogas and synthetic gas will cost $7 to $45 per million British thermal units (mmBtu) by 2040 (reported in 2019 dollars), which is about 3 to 18 times more costly than the current market price for fossil gas of about $2.50 per mmBtu.

The United States uses more than 31,000 trillion British thermal units (TBtus) of natural (fossil) gas annually for generating electricity; heating and cooking in residential and commercial buildings; industrial processes; producing, transporting, and processing gas; and fueling vehicles.

When gas (which is primarily methane) is burned, it produces carbon dioxide and other emissions detrimental to human health, like nitrogen oxides (NOx), contributing to climate and air pollution. Even if the methane is produced from organic materials or generated synthetically through chemical processes rather than fracked from the earth, burning it produces the same pollutants.  

Biogas is often inaccurately labeled “zero emissions” because its fuel sources—organic material—have absorbed carbon from the atmosphere and would have released it as part of a natural carbon cycle. However, as the Issue Brief notes, evaluating the climate impacts of biogas and synthetic gas must account for the energy required to produce them and the associated emissions, whether the source creates new methane where none or little would have existed, and how much of the climate super-pollutant methane leaks during production.

For additional information, see this blog by Merrian Borgeson.


NRDC (Natural Resources Defense Council) is an international nonprofit environmental organization with more than 3 million members and online activists. Since 1970, our lawyers, scientists, and other environmental specialists have worked to protect the world's natural resources, public health, and the environment. NRDC has offices in New York City, Washington, D.C., Los Angeles, San Francisco, Chicago, Bozeman, MT, and Beijing. Visit us at


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