Artificial intelligence startups Anthropic and OpenAI, nearing near-trillion-dollar valuations and preparing for initial public offerings, have not disclosed greenhouse gas emissions, made net-zero pledges, or published sustainability reports. In contrast, Big Tech companies scaling AI infrastructure, including Alphabet Inc.’s Google, Meta Platforms Inc., Amazon.com Inc., and Microsoft Corp., have net-zero goals and report emissions, which are spiking due to the data-center boom. Investors have fallen quiet amid climate backlash, and regulators have retreated, leaving the public guessing about climate pollution tied to OpenAI, Anthropic, and SpaceX’s SpaceXAI. New gas plants for data centers in the U.S. alone could soon generate as much climate pollution as the entire country of Australia, according to the Environmental Integrity Project. 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 to measure its footprint and comply, while OpenAI is coordinating with data center partners and has a sustainability steering committee, citing its Stargate Community commitment to minimize water usage and protect ecosystems. SpaceX didn’t respond to a request for comment.