COP 27: What We Know So Far

On March 23, 2026, the California Air Resources Board (CARB) held a public workshop on implementation of the Corporate Climate Data Accountability Act (SB 253), as companies prepare to comply with initial greenhouse gas (GHG) reporting requirements later this year. The workshop followed CARB’s February 2026 adoption of initial regulations under SB 253 and SB 261, which we discussed here, and focused largely on potential future rulemakings, particularly with respect to Scope 3 emissions, GHG accounting methodologies, assurance and organizational boundary setting.

The California Air Resources Board (CARB) recently finalized a narrowly crafted, initial set of implementing regulations (Regulations) for California’s climate‑reporting statutes (i.e., SB 253 greenhouse gas (GHG) emissions reporting) and SB 261 (climate‑related financial risk disclosures).¹ As adopted, the Regulations largely mirror the proposal issued in December 2025, without material changes. The Regulations provide a limited set of foundational compliance mechanics, but defer many consequential issues to future rulemaking initiatives, particularly in relation to how Scope 3 GHG emissions are to be reported under SB 253.

On February 18, the U.S. Environmental Protection Agency (EPA) issued its final rule repealing the greenhouse gas (GHG) “endangerment finding.” EPA’s leadership has characterized the repeal as a return to a narrower reading of the statute in light of scientific, technological and policy developments since 2009. The move significantly attempts to reshape the federal climate regulatory landscape and promptly drew legal challenges.

In a presidential memorandum issued January 7, President Trump announced the United States will begin executive proceedings to withdraw from a historic number of international organizations, conventions and treaties, including the United Nations Framework Convention on Climate Change and others aimed at environmental protection and climate action.