Governor Gavin Newsom has expanded California’s climate collaboration with the United Kingdom, signing a new Memorandum of Understanding with UK Energy Secretary Ed Miliband and welcoming nearly $1 billion in clean technology investment from UK-based Octopus Energy.

The agreement signals a strengthening of subnational climate cooperation at a time when international alliances are under strain. It also highlights California’s strategy of pairing climate diplomacy with tangible capital flows into its clean economy.

A Formal Climate Accord Between California and the UK

During his visit to London, Governor Newsom and Ed Miliband, the United Kingdom’s Secretary of State for Energy Security and Net Zero, signed an MOU committing both governments to deepen cooperation on climate action and sustainable development.

The agreement builds on longstanding ties between California and the UK, reinforcing collaboration on clean energy deployment, innovation, and climate resilience. Both jurisdictions face mounting climate impacts, including extreme weather, wildfires, and economic disruptions tied to rising temperatures.

For California, the partnership strengthens its position as a global climate actor operating at the subnational level. For the UK, the agreement aligns with its clean energy strategy aimed at strengthening domestic energy security, reducing costs, and accelerating decarbonization.

Governor Newsom emphasized California’s role as a stable and ambitious clean economy destination, pointing to statutory clean energy targets and market-based programs that provide clarity for investors. Secretary Miliband framed the collaboration as an opportunity to support UK business expansion while advancing shared climate objectives.

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Octopus Energy Expands US Footprint With $1 Billion Commitment

The trip concluded at the headquarters of Octopus Energy, a UK-based clean tech company valued at unicorn status. The company announced plans to invest nearly $1 billion in California-based clean energy projects, carbon removal initiatives, and nature-based climate solutions.

The investment underscores California’s appeal as a long-term destination for climate capital. With clear regulatory signals and established climate frameworks, the state continues to attract international firms seeking durable growth opportunities in clean technologies.

Octopus Energy Generation CEO Zoisa North-Bond highlighted the strategic alignment between California’s policy environment and the company’s long-term investment approach. The investment is expected to support project development, innovation, and cross-border economic benefits linking California and the UK clean energy sectors.

California’s Expanding Global Climate Network

The UK agreement adds to a growing portfolio of international climate partnerships led by California in recent years. These collaborations span methane reduction, forest conservation, zero-emission transportation, wildfire management, carbon markets, and clean energy deployment.

Recent agreements include cooperation with Chile on methane reduction, Colombia on forest conservation and biodiversity, Nigeria on sustainable urban transportation and green ports, and Brazil on carbon pricing, wildfire prevention, and nature-based solutions.

California has also advanced partnerships with Australia on vehicle emissions standards and electricity market reform, Denmark on water efficiency and groundwater mapping, British Columbia on wildfire assistance, and Chinese provinces and municipalities on emissions reductions and clean energy transition.

These relationships are supported by California’s involvement in international coalitions such as the Under2 Coalition, the Beyond Oil and Gas Alliance, and the Subnational Methane Action Coalition. Domestically, the state co-founded and co-chairs the U.S. Climate Alliance, representing 24 governors and roughly 60 percent of the US economy.

Filling a Federal Leadership Gap

While formal participation in the Paris Agreement requires federal authority, California has pursued Paris-aligned climate targets through state policy and international cooperation. The state positions itself as maintaining continuity in climate action during periods of federal retreat.

This subnational diplomacy model has allowed California to build what it describes as the largest network of subnational climate partnerships globally. The UK partnership reinforces that approach, demonstrating how state-level agreements can mobilize investment and advance climate policy objectives without direct federal coordination.

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Climate Action and Economic Growth

California’s climate strategy rests on coupling emissions reductions with economic expansion. Since 2000, the state reports a 21 percent reduction in greenhouse gas emissions while GDP increased by 81 percent. The state now ranks as the fourth largest economy in the world.

Clean energy deployment continues to accelerate. In 2023, approximately two-thirds of California’s electricity generation came from clean sources. The state has also operated on 100 percent clean electricity for portions of the day on most days of the past year.

Battery storage capacity has grown significantly, reaching nearly 17,000 megawatts, representing more than a 2,100 percent increase during the Newsom administration. More than 30,000 megawatts of new resources have been added to the grid, with current storage levels accounting for roughly one-third of the capacity projected to be required by 2045 to achieve a fully clean electricity system.

Strategic Significance

The expanded UK partnership and Octopus Energy’s capital commitment illustrate how climate diplomacy, regulatory certainty, and market scale can converge to attract international investment. For California, the agreement reinforces its role as a climate policy innovator and capital magnet. For the UK, it opens access to one of the world’s largest clean technology markets.

As global climate leadership shifts and national politics fluctuate, subnational alliances such as this one are increasingly shaping the trajectory of clean energy deployment and cross-border investment flows.

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