Tom Steyer: Green Giant

Nothing comes free, not even for the President of the United States. So when Barack Obama appeared at Tom Steyer’s San Francisco home for a fundraiser last year, the President had to know there would be an ask. The 56-year-old Steyer is a hedge-fund billionaire and a major-league Democratic donor. He is also convinced that climate change is the biggest threat facing the world—an argument he made clear to Obama that night, when he pressed him to cancel the Keystone XL oil-sands pipeline. “Every generation gets one issue not to muff, and this is the one we can’t muff,” says Steyer. “This is it.”

Obama has long supported efforts to combat climate change and recently directed the Environmental Protection…


This appears in the June 2, 2014 issue of TIME.