Learn more about the state, motivation, and needs of the emerging climate field of methane removal.
Methane is a short-lived, powerful greenhouse gas, currently responsible for 0.5°C of current warming—roughly a third. Staying within safer climate guardrails depends on sharp decreases in its atmospheric levels. However, atmospheric methane levels continue to rise. Cutting anthropogenic methane emissions is our first and most important tool to start bending the curve. At the same time, though, natural methane sources are expected to increase in a warming world. Scientists are increasingly concerned that these changes have already started, and that methane emissions from tropical wetlands are rising today. Permafrost thaw adds additional risk this century, and emissions from both systems will only get worse with more warming.
The emerging field of methane removal may help to address a portion of methane-driven warming and mitigate some of the risks from increasing natural methane emissions, but it cannot replace aggressive greenhouse gas emissions reductions or carbon dioxide removal. Much more research is needed to determine the feasibility and safety of methane removal approaches before deployment could responsibly be considered. This emerging solutions set has unique needs that will require significant support to facilitate integrated research programs and engage partners towards standing up a pragmatic and collaborative new field.
Methane removal approaches are being researched to determine how methane, once in the atmosphere, can be broken down or captured faster than with existing natural systems alone. Methane removal could help to lower peak temperatures and mitigate some of the impact of elevated natural methane releases from wetlands and permafrost as a result of our changed climate.
Should they prove feasible and safe, any deployment of methane removal approaches would need to be in addition to, not instead of, other climate solutions. Any future methane removal capacity should be strictly additive to greenhouse gas emissions reductions, and maximal carbon dioxide removal capacity, each of which will have their own scaling considerations.
Greenhouse gases are not interchangeable. Emissions reductions and removals are not, either.
Carbon dioxide stays in the atmosphere for centuries, while methane stays in the atmosphere for decades. Targets for reductions in both should be managed separately, as their impacts are not fully interchangeable.
It’s also important to distinguish between emissions reductions and removal targets. The conversation has mostly been around carbon dioxide to date — we need to both reduce carbon dioxide emissions as aggressively as possible and in parallel enable the scale up of carbon dioxide removal approaches to enable long-term net-negativity, with separate targets also suggested.
Our overall climate solution portfolio and ambition must grow with further climate challenges, such as anthropogenically amplified natural feedbacks. In the same way that carbon dioxide and methane emissions reductions are not interchangeable, and carbon dioxide reductions and removals should be assessed separately, research towards potential methane removal approaches will need to advance strategically to ensure that our climate ambition scales to match available solutions, rather than substituting continued emissions.
Methane has a short atmospheric lifetime, about a decade, due to substantial methane sinks. The primary methane sink is atmospheric oxidation, from hydroxyl radicals (~90% of the total sink) and chlorine radicals (0-5% of the total sink). The rest is consumed by methane-consuming bacteria and archaea in soils (~5%).
Methane isn’t captured from the atmosphere and stored, like it is for carbon dioxide, but “broken down.” Some methane removal approaches being studied would enhance natural sinks. Others draw inspiration from the biology and chemistry of existing sinks to find new ways to further drawdown methane from the atmosphere faster.
Research into methane removal approaches is ongoing and growing, but still a small research field relative to the scale of need and potential. Robust scientific progress in these areas is important for both approach development and careful study of any potential unintended consequences.
Several categories of approaches are starting to be researched for methane removal:
The scientific field around methane removal is still in its infancy today, but scientific interest in methane removal is quickly growing as awareness of the need and potential becomes more widespread. With no dedicated public funding programs supporting the field, research funding remains a major bottleneck to further growth.
The National Academies of Sciences, Engineering, and Medicine (NASEM) has an active study on atmospheric methane removal, expected out in late summer or early fall 2024.
As an emerging field, methane removal has significant financial, research and policy needs that can best be addressed by civil society and government. Pioneering climate foundations are supporting critical early work in the field.
Integrated research programs are needed to develop and evaluate critical new approaches for methane removal. Such programs will seek to improve foundational understanding of potential methane removal approaches, and move promising approaches to early phase technology development. A combination of direct early philanthropic research funding and government and university engagement will be required to catalyze and support a robust RD&D program.
Enablers: Public funding advocacy and engagement, scientific field-building and early philanthropic funding
An improved understanding of evolving methane sinks and associated non-linear atmospheric chemistry will deepen our understanding of the climate system and potential interventions such as methane removal. This rich area of exploration spans multiple areas of expertise, from analyzing the microbial mechanisms affecting soil sinks to studying the atmospheric chemical mechanisms and conditions that oxidize methane. Making meaningful progress will require modeling, laboratory, and observational studies.
Better sensors and tools will also help to advance our understanding of the oxidation of atmospheric methane by giving greater insight into its mechanisms. The field stands to benefit considerably from the development of new low-cost and robust sensors that can reliably measure small changes to background concentrations of 2 ppm methane. An improved ability to study methane could also be derived from better sensors and platforms, laboratory equipment, software, or other tools capable of measuring methane, carbon or hydrogen isotopes, nitrous oxide, nitrogen oxides, hydroxyl or chlorine radicals, molecular chlorine, or any proxies for these species, in the atmosphere, in soil, on plants, in water, or from space, on a broad range of scales. The complexity of the methane cycle warrants a concerted effort on Measuring, Monitoring, Reporting and Verification (MMRV) development across environments and reaction stages.
Researchers have proposed several approaches for methane removal, and much more research and development is needed to determine which, if any, are safe, cost-effective, scalable, and net climate beneficial. Developing any pathway successfully will require research to ensure that the climate benefits will outweigh any negative climate impacts, the social benefit of the removed methane will be greater than any costs incurred, and that they will be socially-acceptable in light of any secondary impacts.
All of the potential approaches to accelerate the breakdown of atmospheric methane are in early research stages. In each case, fundamental questions remain about their feasibility, scalability, safety, and potential unintended consequences. Research funding is a bottleneck for much of the field.
There’s evidence that methane, nitrous oxide, and carbon dioxide emissions from natural systems are already rising as a result of climate change, driving further warming, and will likely be exacerbated further with every fraction of a degree—yet these dynamics are not yet well-represented in the climate models that we depend on for projecting future scenarios. Better monitoring and understanding of these systems will enable more precise climate projections, especially under a changing climate.
Earth System Models continue to evolve in improving the simulation of interactions between the geosphere, biosphere, hydrosphere, atmosphere and cryosphere. Improved ESM modeling capabilities could allow for greater inclusion of dynamic natural systems responses and methane-emitting natural feedbacks. The oxidation of atmospheric methane is also contingent on a variety of factors that could be better reflected in existing models. While an improved understanding of atmospheric sink dynamics and natural systems (described above) will likely be a prerequisite to their full incorporation in ESMs, modelers can lay the groundwork for their inclusion now by planning, developing and testing the appropriate capabilities.
The prospect of removing methane directly from the atmosphere may give the perception that society has a “backstop” if it continues emitting unsafe amounts of greenhouse gases. A concerted effort should be made to minimize any such conceptions. Methane removal is in the very earliest stages of research and development, and we still do not know whether or not any approaches will prove to be viable and safe. While pursuing a deeper understanding of the potential for methane removal, advocates should focus on lifting up responsible parties that embrace the science comprehensively and do not falsely indicate that it can serve as a substitute for emissions reduction. Methane removal should be viewed only as an additive tool that allows us to increase our overall climate mitigation ambition.
Enablers: Responsible research and engagement, policy and market design
Civil society plays an important role in the acceptance and advancement of emerging technologies through the dissemination of knowledge, creation of new talent pipelines and generation of new interest. Methane removal stands to benefit from these features of more robust civil society education and involvement. Several proposed approaches (e.g., atmospheric oxidation enhancement) involve “open-system” climate interventions, which are inherently higher risk and may have difficulty evolving without focused effort to educate and develop support with the public and stakeholder communities.
Enablers: Philanthropy, policymakers, academia, community groups
The prospect of “open system” methane removal approaches that seek to oxidize methane in the absence of any physical barriers with the natural environment are one of several reasons international engagement may prove to be valuable for the field. Such interventions would be better informed and therefore likely better accepted if they incorporate the viewpoints of a diversity of international partners. If methane removal ultimately plays a role in managing methane-emitting natural feedbacks, international engagement will be needed to address questions of responsible and prudent deployment. At a much earlier stage, improved international collaboration on research may also prove to be catalytic, and as more is learned about existing natural methane sinks, specific jurisdictions may be identified where focused research would be most valuable.
Enablers: Philanthropy, advocates, policymakers, academia
Menu
Stay in touch
Sign up to our Spark newsletter and stay updated!
made by
tonik.com