The methane imperative: Three actions and a tool to cut methane emissions and slow global warming
Renaud de RICHTER
Reducing methane emissions—the “easy” way to keep 1.5 alive?
Three actions and a tool to cut methane emissions and slow global warming
Evidence indicates that methane emissions were responsible for about half of global warming we’ve experienced so far—but compared to carbon dioxide, methane has received comparatively little attention. A team of researchers writing in Frontiers in Science raises the alarm and lays out the three critical imperatives we need to meet to prevent methane emissions spiraling out of control, as well as unveiling a new tool for a tailored, country-specific approach to managing and reducing methane emissions.
To control the climate crisis, we must tackle methane emissions now. Methane has contributed about half the global warming we’ve experienced so far, and emissions are climbing rapidly. An international team of climate researchers writing in Frontiers in Science set out three imperatives to cut methane emissions and share a new tool to help us find the most cost-effective ways of doing so.
“The world has been rightly focused on carbon dioxide, which is the largest driver of climate change to date,” said Professor Drew Shindell of Duke University, lead author. “Methane seemed like something we could leave for later, but the world has warmed very rapidly over the past couple of decades, while we’ve failed to reduce our CO₂ emissions. So that leaves us more desperate for ways to reduce the rate of warming rapidly, which methane can do.”
Reduce, coordinate, and incentivize
Methane is the second most potent greenhouse gas, but only about 2% of global climate finance goes towards cutting methane emissions. These emissions are also rising fast, due to a combination of emissions from fossil fuel production and increased emissions from wetlands, driven by the climate crisis. To slow the damage from climate change and make it possible to keep global warming below 2°C, we need to act immediately, following the Global Methane Pledge to reduce methane emissions by 30% from their 2020 level by 2030.
The scientists lay out three critical imperatives for action, backed by analyses of satellite remote sensing data, reported methane emissions, and the interaction of abatement options with market forces. Firstly, we need to bring methane emissions down. Secondly, we need to coordinate efforts to tackle methane and carbon dioxide emissions—only cutting carbon dioxide won’t stop warming quickly enough, but only cutting methane just delays global heating. Thirdly, we need to incentivize and enforce methane abatement.
This is a life-saving, cost-effective measure. Estimates indicate that every tonne of methane emitted in 2020 caused US$470-1700 of damages. But this may be a significant underestimate: taking into consideration the effect on air pollution that damages human health, the true cost could be up to $7,000 per tonne—and rising.
“The benefits of methane mitigation nearly always outweigh the net costs,” explained Shindell. “Many methane mitigation options provide net economic gains even without accounting for environmental impacts.”
Methane doesn’t accumulate in the atmosphere in the long term, so emissions reductions take effect more quickly. If we could cut all methane emissions tomorrow, in 30 years more than 90% of accumulated methane—but only around 25% of carbon dioxide—would have left the atmosphere.
“The most important mitigations are the available mitigation options across all sectors that aren’t too expensive, because we really need to do everything to reach climate targets such as 1.5 or 2C warming,” said Shindell. “Controlling methane from only one sector wouldn’t be enough. We need a broad portfolio of actions.”
The right tools for the job
The most impactful opportunities to fight methane will depend on the measures a country has already taken and the industries it relies on. So the authors created an online tool to identify the most effective measures for abatement in different countries. For big fossil fuel producers, regulating production, incentivizing the capture of methane, or charging companies for methane emissions could be the most effective options. For others, focusing on emissions from landfills could offer the biggest rewards. Individuals can help by making lifestyle changes and by thinking about the environment when they vote.
“People can make sure they avoid overconsumption of beef and dairy, and compost their organic waste whenever possible,” said Shindell. “If it’s not possible where they live, they can vote for those who’ll create programs for composting in their towns. They can also vote for those who will make polluters pay for methane emission rather than letting them profit while society picks up the tab for the damages they’re inflicting.”
“There are uncertainties, of course,” cautioned Shindell. “We don’t yet have enough data to fully parse out the contributions of individual factors to the recent surge in the observed growth rate, for example. But it is imperative to rapidly reduce methane emissions to reduce the accelerating climate damages so many people around the world are suffering.”
The article is part of the Frontiers in Science multimedia article hub ‘Imperatives for reducing methane emissions’. The hub features an editorial, two viewpoints,
and a policy outlook from other eminent experts: Dr Lars Peter
Riishojgaard (formerly at the World Meteorological Organization,
Switzerland) and Dr Oksana Tarasova (World Meteorological Organization,
Switzerland), Dr Andy Reisinger (Australian National University,
Australia), Fiona M. O’Connor, (Met Office Hadley Centre, UK), and
Durwood Zaelke (Institute for Governance & Sustainable Development,
USA)—as well as an explainer with infographics.
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Front. Sci., 30 July 2024
Three actions and a tool to cut methane emissions and slow global warming
Methane is the second-most important greenhouse gas driving climate change—and levels are rising fast, especially since 2020. Despite this, little action has been taken to reduce methane emissions.
Shindell et al. highlight the faster-than-predicted rise in methane emissions, the reasons for it, and how this threatens our ability to limit global warming to 1.5°C or 2°C. Their Frontiers in Science lead article also outlines three methane “imperatives” for reducing emissions—and provides analyses and a new online tool to help countries optimize cost-effective strategies for reducing methane emissions.
This explainer summarizes the article’s main points.
Why do methane emissions matter?
Methane is a potent greenhouse gas, responsible for about half of global warming since preindustrial times. Alarmingly, methane emissions have risen rapidly since 2006, with 2021 and 2022 recording the largest emissions on record. This rise is much faster than projected by models and, if not addressed, puts our ability to meet climate targets at risk. On the flip side, reducing methane is a cost-effective way to rapidly slow warming.
Methane impacts human health and agriculture too, by contributing to the formation of ground-level ozone. This harmful air pollutant causes premature deaths in adults through respiratory illness and cardiovascular disease and in children under five years old, especially in low- and middle-income countries. Ozone is also harmful to many plants and reduces crop yields.
Why are methane emissions growing?
Previous studies identify three main sources of rising methane emissions since 2006:
fossil fuels, through leaks and incomplete flaring of gas during the extraction, processing, and transport of oil, natural gas, and coal
agriculture, mainly through increased numbers of livestock and, to a smaller extent, expanding rice production in Africa
natural wetlands, where global warming is causing faster decomposition of organic matter by methane-producing microbes.
Shindell et al. conclude the 2020-2023 spike is driven mainly by the fossil fuel sector, especially oil and gas operations, and surging emissions from wetlands due to La Niña conditions.
While landfill is another major source of anthropogenic emissions, these are unlikely to have increased recently. Other natural sources, such as thawing permafrost, currently make only a small contribution to total methane emissions.
What are the three methane imperatives?
The authors call for three actions, or imperatives, for reducing methane emissions.
1. Reverse the growth in methane emissions across all major anthropogenic sources: fossil fuels (coal, oil, and gas), agriculture (livestock and rice), and landfill.
2. Align methane and carbon dioxide (CO₂) mitigation to reduce atmospheric levels of both gases simultaneously, instead of the current focus on CO₂.
3. Optimize technologies and policies for methane abatement at a global, national, and sector level.
How can we reduce methane emissions?
Reducing methane emissions requires a mix of technological solutions and systemic changes to practices and behaviors. The authors show the majority of these are cost-effective—but need strong policy measures to support their broad adoption.
Technological solutions include capturing methane and using it for energy generation; minimizing leaks from fossil fuel operations by repairing infrastructure; improving the efficiency of gas flaring and eventually phasing it out; and inhibiting methane-producing microbes in cattle, through vaccines and feed supplements, as well as in treatment facilities for manure and other organic waste.
Systemic changes include reducing livestock numbers through improved productivity and dietary shifts towards plant-based foods; reducing emissions from livestock; using rice cultivars with lower methane emissions; improving water and fertilizer management in rice cultivation; and diverting organic waste from landfills through recycling, composting, and reducing food loss and waste.
Policy measures for methane abatement include emission reduction targets, enforceable regulations, and financial incentives such as subsidies and methane pricing.
Why do we need to reduce CO₂ and methane emissions at the same time?
Methane and CO₂ are the largest contributors to global warming—so we need to cut both to meet climate goals. Their different properties mean we can maximize climate benefits by reducing each at the same time.
CO₂ remains in the atmosphere for centuries, leading to long-term warming. Methane, on the other hand, is a much more potent greenhouse gas, but has a much shorter atmospheric lifespan of about a decade. By limiting short-term warming through cuts to methane emissions, we can more easily achieve long-term CO₂ reduction goals and minimize reliance on carbon removal technologies. This integrated approach ensures we can keep the 1.5°C global warming target within reach, reduce overall climate impacts, and avoid the worst effects of climate change.
How can countries optimize methane reduction strategies?
Countries need to prioritize investments in the sectors, technologies, and practices that can reduce the most methane emissions within their national context. To guide this, the authors mapped the sector per country with the largest and most feasible potential for methane mitigation. They then analyzed the cost-effectiveness of options in different sectors, in the 50 countries with the largest potential for reducing methane emissions in the next decade.
The authors created a new online tool that allows countries to explore these options and generate an optimized, economically viable national methane reduction strategy. The tool also incorporates some data from satellite observations, with more planned. These data enhance the accuracy of emission estimates and allow identification of methane super-emitters—helping countries to target their efforts to the most significant emission sources. Real-time satellite data can also ensure accountability and track progress towards methane reduction targets.