Founder, Virgin Group
Why he matters: Branson has made billions from Virgin Atlantic Airways, Virgin Trains, Virgin Limousines, and some 200 other Virgin brands. Having done his part to deplete the ozone layer, he's now trying to make amends.
In September he announced that he will donate all profits from Virgin's transportation businesses during the next decade -- a sum that could exceed $3 billion -- to combating global warming. Then he and Al Gore set up a $25 million prize for the first inventor who develops a cost-effective way to extract greenhouse gases from the atmosphere. Now he's partnered with Boeing and General Electric to produce a biofuel to power the jets of the future. It's the least he could do.