The pending Trans-Pacific Partnership (TPP) trade agreement has raised controversy, fueled by leaks of the draft text and congressional debate over fast-track negotiation authority. Like similar agreements, the TPP creates the risk of government liability for enacting regulations, especially new or comprehensive measures to address climate change. This Article analyzes how the TPP’s investor protection provisions and dispute settlement mechanism might be invoked to challenge climate change policy. The author concludes that the negotiators’ efforts to date are insufficient to protect climate measures from the risk of liability and suggests reforms to the draft text.