Atmospheric Methane Removal Principles

The Why

• We’re in the midst of an unfolding and accelerating climate crisis, leading to an increasingly unstable climate system, with accelerating human system impacts.
• Decreasing long-term (centuries-scale) warming is crucial for climate systems stability, and should be targeted to return to stable regimes to repair the climate. Even a 1.5°C world is not a safe one, and our ambition must be to return the climate to a stable state. In addition, the path we take to get there matters, and near-term warming over the next few decades will play a large part in dictating peak temperatures, with resultant climate feedback and tipping element impacts.
• Methane emissions reductions, alongside CO₂ reduction and removal, are all absolutely necessary to stabilize the climate system, but are unlikely to be sufficient given the state of warming today, warming trajectories, and earth system risks.
• Climate feedbacks and tipping elements add more risk to the climate system than has been fully integrated into current earth systems models and general discourse. Peak temperatures and overshoot will influence the number and scale of these feedbacks that perturb the system, some of which further contribute to warming, some of which are irreversible, and all of which will further impact human and ecological systems.
• A number of these feedbacks emit methane, driving the risk of methane-driven warming feedback loops. Our number one job is to avoid triggering these feedbacks in the first place by mitigating warming. However, given the current state and the risks these feedbacks pose, ways of preparing for, and mitigating the impact of, these scenarios must also be pursued in parallel, even without their full risk yet being known.
• Natural methane emissions are increasing as the planet warms and this increase may be nonlinear. Elevated methane emissions from wetlands have not yet been incorporated into most model outputs used by the IPCC (source). Thawing permafrost will be a source of additional greenhouse gas emissions, and the split between emitted carbon dioxide and methane is currently poorly constrained (source). Undersea methane hydrates pose some additional risk of high-impact methane release events (source).
• There’s high value in building out a portfolio of “risk management” solutions that can help to decrease future risks and uncertainties in how the climate system evolves. It’s crucial that where different approaches can and should be additive to each other, that they’re not treated as alternatives to each other. No risk management portfolio is perfect, and reducing risk in the first place (emissions reductions) is always the best first line of defense.
• Atmospheric methane removal is one category of approaches that could help avert the worst outcomes by preventing or reducing future feedbacks, or as an emergency response to sudden increases.

The How

• There are a number of potential technology-based atmospheric methane removal pathways. All of them require additional research, development, testing, and evaluation to determine which may ultimately be most useful to society.
• Accelerated and expanded research and development is urgently needed on atmospheric methane removal pathways, additional approaches to these same risks, and supporting advancement of climate science and modeling around short-lived climate pollutant atmospheric dynamics and natural feedbacks.
• We believe that for atmospheric methane removal to be most impactful as a climate solution, we need to be beginning to reach meaningful scale (e.g. >10Tg methane per year) by 2035, and that more work is needed in setting target scales for this set of approaches. This demands of us acting with purpose and rigor in order to push forward on research efforts, while also identifying and pre-emptively working through potential roadblocks to solution development.
• After robust research efforts, it may be found that there aren’t safe, scalable, and effective atmospheric methane removal solutions. Knowing that is success, too. 
• The future available scale, if any, of atmospheric methane removal solutions is not known. We must not depend on these solutions coming into existence, or at large scale. Research into this area is no reason to decrease any greenhouse gas avoidance ambition. Should an atmospheric methane removal pathway be developed to the stage of possible deployment, it should never be done in place of available methane emissions avoidance options.
• Potential atmospheric methane removal pathways greatly vary, from potential biological systems, to relatively closed systems with air flowing through them, to atmospheric intervention methods. Each method will need to be treated differently with respect to governance, community engagement, and oversight at the testing and at various deployment stages, based on its estimated set of ecosystem impacts. Some of these methods may be able to help reduce climate risks eventually, but at present we do not have enough research and testing to know the efficacy and impacts of each of these methods.
• We believe that it is critical to support every piece of the system and not skip steps (basic science, solution R&D, understanding of broader impacts, government & policy, social license) in developing a solutions field; skipping steps creates a greater risk of unacceptable unintended consequences, and puts the rapid and safe deployment of a given solution at a meaningful scale at risk due to lack of support.
• Controlled field trials are a core part of research and development, but should always have clear scientific value that can’t as readily be achieved another way. If executed rigorously, they provide crucial information to evaluate efficacy and real-world impacts.
• Rigorous and transparent monitoring and evaluation frameworks to study environmental, social, and economic effects are critical to avoid unintended consequences and to develop public awareness and confidence in the approaches.
• Sound and inclusive governance systems will be essential to planning, testing, development, and any potential future deployment of atmospheric methane removal methods. A well-developed governance system would ideally provide mechanisms to balance the risks of testing atmospheric methane removal technologies against the risks of failing to develop adequate solutions. Governance systems should also facilitate transparency and information dissemination to ensure that atmospheric methane removal develops equitably and globally.
• We believe that decisions in this space should involve the affected parties and be well-informed of the potential earth systems risks. To that end, we support the creation of the best information possible to guide the best decisions possible.
• Earth and human systems are complex. When looking at any potential solution, we need to consider the  set of direct and indirect impacts on climate, human health, ocean and terrestrial system impacts, and biological systems impact. Good intentions don’t guarantee good outcomes. Narrowly focusing on a single type of positive impact can miss realizing that there is a different type of negative impact elsewhere in the system.
• We believe that the consideration of the deployment of any solution must be compared to other options immediately on the table, and the impact of not deploying, and then the associated risks and potential impacts that come with each option. The status quo climate system comes with many of its own risks, including irreversible ecosystem changes, increased frequency and severity of severe weather events, further climate tipping elements and feedbacks, etc.
• We believe in communicating progress cautiously, staying in sync with the latest published science to minimize the risk of overpromising or prematurely closing pathways.
• We wholeheartedly second the UNFCCC Article 3 Principles, including: “The Parties should take precautionary measures to anticipate, prevent or minimize the causes of climate change and mitigate its adverse effects. Where there are threats of serious or irreversible damage, lack of full scientific certainty should not be used as a reason for postponing such measures, taking into account that policies and measures to deal with climate change should be cost-effective so as to ensure global benefits at the lowest possible cost. To achieve this, such policies and measures should take into account different socio-economic contexts, be comprehensive, cover all relevant sources, sinks and reservoirs of greenhouse gases and adaptation, and comprise all economic sectors. Efforts to address climate change may be carried out cooperatively by interested Parties."