This study investigates the reaction to the Securities and Exchange Commission’s (SEC) 2010 interpretative guidance on climate risk disclosures. Issued on February 8, 2010, the release represents one of the few examples of authoritative requirements for environmental disclosure in filers’ 10-K reports. As such, we attempt to determine the effect of the new requirement on companies’ disclosures as well as how the market reacted to the guidance announcement. Based on a sample of 155 large companies drawn randomly from the Fortune 500, we find first, that, as expected, climate change disclosures increased significantly following the release, but overall, the information provision remained quite limited. We further find that, presumably as intended, companies from industries facing greater climate change exposures exhibited significantly larger increases in disclosure (controlling for prior levels of information provision). Finally, we document that the market reaction to the release of the SEC guidance was significantly positive and driven by more positive returns from firms in climate risk industries. We interpret these unexpected findings as potentially being due to investors believing the new requirements were less demanding than might have been anticipated or that they believe firms facing climate risks were in a better position to respond than other companies.