In recent years, corporations and their agents have played an increasing role in the national conversation on climate change, with companies weighing in not only on policy debates but also participating in discussions of climate science. To better understand this growing corporate influence, we analyzed the actions of many of the most highly engaged companies. Our analysis reveals that while some American companies have taken consistent and laudable actions in support of climate science—and of consequent policy—others have worked aggressively to undermine the science and block sciencebased policy proposals. Still other companies have taken contradictory actions in different venues. Such inconsistent corporations create confusion by representing the scientific consensus accurately in some venues but not in others, and by supporting politicians, trade groups, and think tanks whose positions are in direct conflict with one another. The resulting defeat or delay of policy efforts to address climate change has huge implications for government, the economy, public well-being and the planet. Greater transparency in corporate activities can further illuminate the corporate influence, both positive and negative, that this report has been able to document. We thus recommend specific actions that policy makers, investors, consumers, and the media can take in order to guide the nation down a path of greater corporate accountability.