Climate change has become one of the most important and challenging environmental issues of our time. Federal action is not a question of if, but when, and new regulations on greenhouse gas emissions will pose new obstacles and opportunities. Meanwhile, domestic and international pressures are motivating states and regions to create a regulatory patchwork that is complex and ever-changing. The ramifications of greenhouse gas regulation extend far beyond the traditional environmental realm of corporate and business issues. Although the first wave of regulations is clearly focused on the energy sector, future regulation will affect additional industries such as cement manufacturing, agriculture, and even high energy usage operations of all types. And before these new regulations are enacted, shareholders and the SEC will expect an even broader range of affected industries to accurately assess and publicly report on business risks.