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Three-step plan to cut overlooked methane emissions could help us stop global warming faster
Evidence indicates that methane emissions were responsible for about half of global warming between the preindustrial period and the 2010s—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 2°C 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.”
Expert Reaction
These comments have been collated by the Science Media Centre to provide a variety of expert perspectives on this issue. Feel free to use these quotes in your stories. Views expressed are the personal opinions of the experts named. They do not represent the views of the SMC or any other organisation unless specifically stated.
Robert McLachlan, Distinguished Professor in Applied Mathematics, Massey University, comments:
The article by Drew Shindell and fourteen other international climate scientists arrives at a timely moment for New Zealand, as our second emissions reduction plan covering emissions to 2030 and the pathway to 2050 and beyond is in preparation. Two reviews of our methane target are in preparation, one by the Climate Change Commission and one by a separate, newly appointed panel as part of the Government’s Coalition Agreement.
Atmospheric methane levels have accelerated recently and are increasing at twice the forecast rate. Therefore, emissions must decrease faster than anticipated. For a 1.5 ºC future, global methane emissions must fall 35% by 2030 and 53% by 2050. The article supports the split gas approach in which agricultural methane emissions do not need to reach net zero; nevertheless, they should fall 20% by 2030 and 30% by 2050.
However, in a separate commentary, Andy Reisinger (not an author of the study) notes that these projections relied on immediate and deep cuts to all emissions from 2020. As this did not take place, ambition should be raised to include faster cuts in CO2 and/or methane, possibly leading to net zero emissions of all gases.
Shindell et al. suggest that the alternative climate metric GWP* has been misused to argue that current levels of methane emissions cause “no additional warming”, and that this “ignores emissions responsible for roughly half the warming to date and appears to exempt current high methane emitters from mitigation. This is neither equitable nor consistent with keeping carbon budgets within reach.” Two of the five members of the new methane review panel were authors of the original GWP* study.
New Zealand can be proud of our political commitment under the Global Methane Pledge and its opportunity to contribute to this global target.