Chasing Methane From Sacramento to the Streets of London

California and the United Kingdom have formalized a climate partnership, committing to joint action on methane reduction only weeks after the United States formally withdrew from the Paris Agreement. Governor Gavin Newsom and the British energy secretary, Ed Miliband, signed the memorandum of understanding in London on Feb. 16, 2026. The agreement deepens bilateral cooperation on clean energy and sustainable development, explicitly embedding methane abatement into a series of deals California has maintained with partners including Chile, Colombia, and Nigeria.

The agreement targets methane emissions across the waste, agriculture, and energy sectors, layering specific commitments across an expanding international network. At the center of this strategy is the Subnational Methane Action Coalition, an initiative launched at COP28 that now spans five continents. Member jurisdictions including regional governments in Mexico, South Africa, Brazil, Germany, and South Korea have committed to aggressively cutting a gas that is roughly 80 times more potent than carbon dioxide over a 20-year period. Scientists have noted that methane accounts for nearly 30 percent of current global warming.

The partnership arrives at a pivotal moment for international climate diplomacy. After the United States’ withdrawal from the Paris Agreement took effect on Jan. 27, 2026, a gap emerged in global coordination that subnational governments are moving quickly to fill. California officials have positioned this coalition-based network as a durable alternative to federal frameworks, suggesting it can maintain emissions accountability regardless of shifts in Washington.

While the pact focuses on policy, it also carries significant commercial weight. Octopus Energy, a British clean-technology firm, announced nearly $1 billion in California investments during the London visit, targeting carbon removal and nature-based solutions. Yet the shift toward subnational diplomacy also places new pressure on the private sector. Analysts suggested that for oil and gas producers supplying markets aligned with California or British standards, independent methane verification is becoming a commercial expectation rather than a voluntary option.

The expansion of state-led diplomacy suggests that subnational actors are no longer peripheral to global climate goals. As the coalition grows, the window between voluntary disclosure and mandatory performance standards continues to close. These regional standards are increasingly likely to shape the regulatory landscape of global energy markets in the years ahead.