Corporate America does not speak with one voice on climate change. On the one hand, hundreds of companies recognize the gravity of the environmental, social, and economic disruption that the majority of climate scientists are predicting, and are taking action to reduce their exposure to the financial risks of climate change, quantify and control their greenhouse gas emissions, and adapt to impacts either now occurring or just over the horizon. On the other hand, many companies seem content to follow the passive approach that the federal government is taking, apparently hoping that it is a false alarm being sounded by climate scientists. This Comment discusses why the time has come for the directors and officers of the major companies that have not yet come to grips with the issue of climate change to do so. Corporate directors and officers have a fiduciary obligation to be reasonably well-informed on material issues affecting their businesses. Due to the substantive work of the scientific community over the past two decades, a mountain of information has now accumulated regarding the nature and scope of the climate problem, and (with the assistance of internal and external experts) corporate managers can utilize that information in their strategic decisionmaking.