WHAT YOU DO: Green up your employer by whatever means necessary. "You're half MacGyver, half Bill Nye the Science Guy," explains Luke Cartin, environmental manager for Vail Resorts. For Jill Dumain, director of environmental analysis at Patagonia, tasks have included installing solar panels and helping the cafeteria serve more organic foods. The sweetest positions allow for numerous hours outside. "A lot of things I go to check out are on my mountains," says Cartin. Then there's your squeaky-clean conscience: Many in the field report that they sleep very, very well.

WHY NOW: More and more Fortune 500 companies are hiring corporate sustainability officers—Mitsubishi and Dow Chemical added positions last year—and at least 35 schools offer M.B.A.s with a focus in sustainability.

THE NUMBERS: Salaries for M.B.A.s start at about $65,000. Directors of departments at large companies earn well over $100,000—but few work less than 50 hours per week.

BREAKING IN: If you don't have an undergraduate degree in environmental science, consider working or volunteering at a nonprofit for training. An M.B.A. with a focus in corporate sustainability is a surefire résumé builder (best programs at Michigan, Yale, Duke, and Bainbridge Graduate Institute, in Washington State). See the Grist.org jobs board.