In response to the growing role that methane plays in the climate crisis, yesterday the National Academies of Sciences, Engineering, and Medicine released a report – and helpful interactive overview – on methane removal, describing the first of a recommended two-phase assessment, recommending $50-80 million per year in research funding for the next 3-5 years to advance understanding of atmospheric sinks and sources, possible methane removal technologies, related governance and social science questions, and systems-level application considerations. This report is timely as atmospheric methane concentrations continue to increase at an accelerating rate, with two of the last four years having the highest growth rate on record. Methane is 80 times more potent than carbon dioxide over a 20 year period and has caused 0.5℃ of current warming, posing a serious, growing, and severely under-addressed risk.
Emissions reductions are the first priority to limit atmospheric methane concentrations. Even if all known emissions reduction approaches are implemented, there is still a gap between the level of emissions reductions needed to achieve temperature targets and the level of emissions that can be achieved by implementing all technically available mitigation measures. This motivates research into new emissions reduction approaches and potential methods to accelerate the breakdown or removal of methane from the atmosphere.
Spark is excited to see this newly published report synthesizing the growing body of scientific work on methane removal. The recommendations in the report align with and expand on the research Spark has been funding over the last three years, and, if implemented, will grow the field in important ways, and help to answer priority research questions. The National Academies report calls for “integrative and transdisciplinary” research across multiple dimensions to address knowledge gaps and develop an assessment framework.
Despite evidence of growing natural methane emissions, and associated risk of near-term temperature overshoot and triggering of climate tipping points, scientists have only started to scratch the surface of potential high-impact research into methane removal approaches. Funding specific to methane removal has been minimal to date, with no dedicated public funding programs, and an estimated less than $10 million put into the research field from all sources, globally, the majority of which has been done philanthropically through Spark. Carbon dioxide removal research similarly struggled with insufficient support until focused attention from leading bodies – such as the National Academies, the IPCC, and climate-motivated philanthropies and non-profits – provided sufficient structure and motivation to advance the field. There is particular urgency associated with the methane challenge, as its very high near-term potency poses a risk of overshooting temperature targets. The report calls for the creation of “transparent funding streams and maximizing publicly funded research [that] can help build credibility and legitimacy and ensure that publicly-interested research remains in the public interest.”
Highlights from the report include:
Rising atmospheric methane concentrations present near-term warming and temperature overshoot risks. Methane and carbon dioxide play different roles in the climate system: carbon dioxide drives long-term warming while methane drives near-term warming and potential temperature overshoot. As detailed by the National Academies report, reducing methane “can influence both the timing and magnitude of peak warming compared to deep decarbonization scenarios that only reduce carbon dioxide emissions.”
There are multiple motivations for methane removal. These include, (1) in response to potential large increases in natural methane emissions (e.g. amplified emissions from wetlands or permafrost), (2) to restore atmospheric and ecological health, and (3) to address the methane emissions gap, where the required emissions reductions exceed “the maximum technical potential for reducing anthropogenic methane emissions.”
Methane removal approaches could take multiple forms—some could be open, lacking physical boundaries, or partially closed, constrained by physical boundaries. Open system approaches may hold more potential for impact and scalability, but also have increased risk for unintended consequences and social acceptability constraints. Partially closed system approaches, including reactors and concentrators, may have lower risks and fewer unintended consequences, but may also have more limited potential for scalability and impact. Governance and social considerations will vary accordingly.
Methane removal approaches all require scientific and/or technological advancements. The global mean methane concentration is currently slightly below 2 ppm, ~200x lower than the concentration of carbon dioxide. Methane’s dilute concentration, coupled with its stability, makes it a difficult target for removal. Most potential approaches oxidize methane, which doesn’t require it to be separated or stored, and provides potential pathways to enhance existing natural oxidation pathways.
Understanding potential methane removal approaches depends on advancing both physical and social sciences foundational research iteratively and in parallel. The National Academies report identifies that “the recommended foundational research not only would advance understanding of atmospheric methane removal but also would be an investment in filling knowledge gaps in other related fields, representing a co-effective use of limited resources for research.”
Several open system methane removal approaches mirror natural methane breakdown mechanisms. Atmospheric reactions account for ~95% of natural methane breakdown, while methane-consuming microbes account for the remaining ~5%. Exploring ways to learn from and amplify the natural removal processes is the basis for some of the approaches that are being considered. Unlike carbon dioxide removal technologies, these methane removal processes don’t require durable sequestration, but rather chemical or biological conversion to be less potent.
An overarching theme for all potential methane removal approaches is the need for systems level assessment to evaluate feasibility, scalability, net climate impact, social acceptability, and legal frameworks. As outlined in the report, it is essential to fold these considerations in from the onset so that they can iteratively inform each other. The report identifies methane removal as a sociotechnical problem, and calls for both foundational and systems level research. Transdisciplinary and convergence research across multiple dimensions is essential to avoid unanticipated impacts, as highlighted by the challenges faced in other early climate intervention fields.
To date, research into promising potential methane removal approaches has been funding limited. Early funding in this space has been outpaced by researcher demand, with researchers coming forward with innovative, high-impact research topics that are in dire need of more funding support. The National Academies report identifies five distinct areas in need of support to advance the understanding of methane removal: 1) Methane sinks and sources, 2) Methane removal approaches, 3) Social science research, 4) Applied social dimensions research for methane removal, and 5) Understanding the applications of methane removal.
The National Academies report will serve as a focal point for the research community, as well as the agencies and organizations who support this nascent field, to coalesce around a body of ideas and priorities. To build the foundational and system understanding to assess next steps for methane removal approaches, and meet the creativity and ambition of researchers entering—and wanting to enter—the field, funding will need to grow across federal agencies, as well as philanthropically. The report funding recommendations for a first phase of assessment serve as a good starting point for further field growth. Spark is eager to see a swell of support for the priorities that are identified in the report, recognizing this as a pivotal opportunity to develop knowledge around methane removal as a potentially critical part of the climate response portfolio.
