Reducing the amount of methane going into the atmosphere via anaerobic digesters and other means is an important short-term step for addressing climate change, a top scientist says.

A lot of the emphasis for reducing greenhouse gases to slow climate change has been on the oil and gas sector, but reducing methane emissions is gaining attention and got a boost from the Global Climate Pledge launched in 2021.

There are 158 countries participating in that initiative, with the goal of reducing methane emissions by 30% from 2020 levels by 2030.

Methane is the “single biggest lever we have to slow warming in the short term,” said Matt Tomich, president of Energy Vision, an environmental research group.

Energy Vision has been researching the potential of organic waste in terms of climate and public health, electricity generation and nutrient recovery for the better part of 15 years. Its new report — Meeting the Methane Challenge — offers a roadmap for how the U.S. can reach its 30×30 goals.

Organic waste

Organic and agriculture waste and the potential to transform the waste streams into a climate benefit versus a liability was at the heart of the assessment, he said.

“So we wanted to know, compared to oil and gas measures, including those on the books now, how does deployment of anaerobic digesters, in particular, stack up,” he said during a livestream congressional hearing on Sept. 20.

Based on existing technology and known feedstocks — whether agricultural or municipal — the research found there is the opportunity to deploy close to 5,000 new anaerobic digester systems across the country, across the different waste streams, he said.

Based on some conservative estimates on leakage, the researchers calculated that would get the U.S. nearly half of the way to the 30% by 2030 goal.

Private investment

Estimates suggest that would require close to $75 billion, and the private sector is poised and lining up to deploy those dollars, he said.

“This strategy alone plus oil and gas measures based on our research essentially gets us to the 30% goal and beyond. But time is of the essence, seeing as we’re late in ’24 and 2030 is less than six years away,” he said.

Research in collaboration with Argonne National Laboratory found the deployment of operational and under-construction natural renewable gas facilities in the U.S. has had 10-fold growth from 2014, with well over 400 now operating or under construction.

“We have seen a significant uptick in this infrastructure but a fraction of what’s potentially available … and what needs to happen in order to ensure we stay on track,” he said.

Win-win

The output of these digesters is biogas, primarily methane, which can be used directly on site for purposes like generating heat and power. If you clean it up, remove CO2 and impurities, it becomes interchangeable with fossil natural gas,” he said.

Looking ahead, there’s a lot of activity, research and excitement around its use as a biointermediate to make things such as renewable jet fuel or bioethanol. So it’s highly versatile, and capturing methane and putting it into production is a win-win, he said

The importance of oil and gas measures can’t be overemphasized, and they are the lowest hanging fruit in terms of cost effectiveness

“But all these different digester-type strategies are … quite compelling on a cost-effectiveness basis,” said.