Virgin Group founder Sir Richard Branson is known for taking on challenges big and small, but the mega-marketer says leaders from firms of all sizes can help solve some of the most striking problems facing society. "Responsible capitalism is trying to think of ways in which you can invest proceeds from your company into ventures that benefit the environment," Branson says. He suggests a divide-and-conquer approach, whereby smaller companies could tackle local problems while slightly bigger companies target national issues and larger corporations battle international challenges.