Climate Break
Methane is one of the most powerful drivers of near-term global warming, and also one of the fastest opportunities to slow it down. In this episode of Climate Break, we explore how a global network of states and provinces is working together to reduce methane emissions through shared knowledge, technical assistance, and peer learning. Ethan Elkind speaks with Shivani Shukla, a methane research fellow at UC Berkeley, about the Subnational Methane Action Coalition (SMAC) and how subnational governments can play an outsized role in addressing this urgent climate pollutant.
Methane is a colorless, odorless gas responsible for nearly one-third of current global warming. Over a 20-year period, methane traps roughly 80 times more heat per molecule than carbon dioxide. Its climate impact is further amplified by the way it contributes to the formation of tropospheric ozone and adds water vapor to the stratosphere, increasing its overall warming effect.
Unlike carbon dioxide, methane comes from a relatively limited set of sources. Major contributors include landfills and wastewater facilities, agriculture (particularly livestock digestion and rice cultivation), and fossil fuel systems such as oil, gas, and coal operations. Because these sources are concentrated and well understood, methane reductions are often technically feasible and cost-effective, especially when captured methane can be repurposed as fuel.
Launched at COP28 in 2023, the Subnational Methane Action Coalition is a global network of state and provincial governments working to reduce methane emissions. SMAC began with 15 founding members, spearheaded by California, and has since expanded to include dozens of subnational governments and observers worldwide.
SMAC is supported by researchers at UC Berkeley’s Center for Law, Energy & the Environment, which provides participating governments with technical assistance on methane inventories, policy design, and action planning. The coalition also connects members with experts, data partners, and peer jurisdictions that have implemented successful methane reduction strategies.
Climate policy is often designed and implemented at the national level, but states and provinces frequently have direct jurisdiction over major methane sources, including waste management, agriculture, and energy infrastructure. Subnational governments are therefore uniquely positioned to pilot solutions that can later be scaled nationally or replicated elsewhere.
Through SMAC’s peer network, members can share lessons learned, adapt policies to their regional contexts, and avoid duplicating efforts. A state that has developed an effective approach to reducing agricultural methane, for example, can share that model with other regions facing similar challenges.
One of SMAC’s key strengths is its emphasis on capacity-building. Many subnational governments (particularly those with limited resources) lack the technical expertise or staffing needed to design and implement methane mitigation programs. SMAC addresses this gap by offering tailored technical support, expert-led webinars, and communities of practice focused on specific methane sources.
Methane mitigation also offers strong near-term climate benefits. Because methane dissipates from the atmosphere more quickly than carbon dioxide, reducing emissions can slow warming almost immediately. In many cases, methane solutions are relatively low-cost and non-repetitive, involving infrastructure upgrades or operational changes rather than ongoing behavioral shifts by individuals.
Despite its promise, SMAC faces several challenges. Political turnover can disrupt momentum, as changes in leadership may shift climate priorities or reduce ambition. Sustained funding is another barrier, particularly for jurisdictions that need upfront investment to implement methane reduction technologies.
There is also an important broader critique: focusing heavily on methane should not come at the expense of long-term carbon dioxide reductions. While methane mitigation is a powerful short-term strategy, CO₂ remains in the atmosphere far longer and continues to drive warming over centuries. SMAC does not frame methane reduction as a replacement for CO₂ action, but rather as a complementary strategy within a broader climate portfolio.
Shivani Shukla emphasizes that SMAC is fundamentally about collaboration and shared learning. By connecting subnational governments across regions and sectors, the coalition helps members overcome technical and capacity constraints while fostering leadership on methane mitigation. She also highlights the global nature of methane pollution and the importance of cross-border cooperation to address it effectively.
Shivani Shukla is a Research Fellow in the Project Climate program at UC Berkeley Law's Center for Law, Energy and the Environment (CLEE). Shivani co-leads the Subnational Methane Action Coalition, where she focuses on climate and environmental policies, particularly on methane and natural resources at the subnational level. Prior to joining CLEE, Shivani was a two-time EDF Climate Corps Fellow and conducted interdisciplinary climate policy research across academia, private and public sectors in the U.S.A., Ireland and India. Shivani graduated from the MPP program at the University of Chicago and a Masters in Applied Economics from University College Dublin. She is currently based in New York.