Publicly traded companies are required to transparently disclose material business risks to investors through regular filings with the Securities and Exchange Commission (SEC). On January 27, 2010, the SEC voted to publish Commission Guidance Regarding Disclosure Related to Climate Change, which clarifies how publicly traded corporations should apply existing SEC disclosure rules to certain mandatory financial filings with the SEC regarding the risk that climate change developments may have on their businesses. The Guidance has been controversial and has prompted legislation in the 112th Congress to repeal it.Proponents of the Guidance, including several union and public pension funds, have argued that it was necessary because a consensus has been established on the reality of climate change and that, given the salience of climate change and the various related legislative and regulatory responses to it, the Guidance would help foster a better understanding of how the SEC’s existing disclosure requirements applied to it. Some that oppose the guidance, including several business interests, argue that the current state of the science and the law underlying the idea of global climate change remains uncertain; existing SEC disclosure rules are adequate with respect to corporate reporting on environmental change; and while certain interest groups had advocated for such climate change disclosure guidance, the climate change disclosure guidance’s usefulness for most investors is unclear.In the 112th Congress, Senator John Barrasso and Representative Bill Posey introduced identical bills (S. 1393 and H.R. 2603, respectively) that would prohibit the enforcement of the SEC’s climate change disclosure guidance.Since the Guidance went into effect on February 8, 2010, there have been several attempts to gauge its impact. A 2011 report from Ceres, a nonprofit coalition of institutional investors, environmental organizations, and other public interest groups, concluded that most corporate filers needed more experience at communicating the risks associated with climate change. Although it found that large public companies had improved their climate-change risk disclosures in recent years, the report concluded that there was more work to be done in this area.A report from the law firm of Davis Polk & Wardwell found that the Guidance did not appear to have had as significant an impact on disclosure as some had expected; that new disclosures emerged involving potential changes in demand for products and services and increases in fuel prices; and that there was little disclosure of actual or potential reputational harm that might result from climate change.A third study published for the American Bar Association found that many companies reported seeing little upside and even less downside in climate change disclosures. It also found that many companies reported few meaningful business opportunities resulting from climate change disclosures, which instead carried a potential for creating risks. In addition, many companies indicated that disclosing frequently uncertain climate change-related information was often a very speculative process and that there were few, if any, penalties from the SEC for nondisclosure of climate change matters. This perception was underscored by other observations that characterized the SEC’s level of enforcement in this area as negligible.This report will be updated as events warrant.