OpenAI and Anthropic, two US artificial intelligence startups nearing trillion-dollar valuations, have not disclosed greenhouse gas emissions, made net-zero pledges, or published sustainability reports ahead of potential IPOs, though Anthropic joined a carbon-removal coalition called Frontier. While fossil-fuel companies like ExxonMobil Holdings Corp. and Big Tech firms such as Alphabet Inc.’s Google, Meta Platforms Inc., Amazon.com Inc., and Microsoft Corp. report emissions and have net-zero goals, investors have fallen quiet amid climate backlash and US regulators have retreated. New gas plants for data centers in the US alone could soon generate as much climate pollution as the entire country of Australia, according to research by the nonprofit Environmental Integrity Project. Ioannis Ioannou, an associate professor at the London Business School, said, “They should absolutely be disclosing,” citing potential environmental impact of an unprecedented scale. California’s law SB253 begins to go into effect in November, requiring companies with more than $1 billion in revenue doing business in the state to report Scope 1 and 2 greenhouse gas emissions, applying to activity outside the state. Anthropic is working with Watershed, a carbon accounting and emissions disclosure platform, to measure its company-wide footprint and comply with the law, according to a company spokesperson. OpenAI is coordinating with its data center partners ahead of the requirement.