The 2008 TIME 100

Isaac Berzin recently signed a $92 million contract to grow the stuff most people scrape out of their fish tanks. His improbably valuable crop is algae, which may one day provide us with a way out of our dependency on fossil fuels and the climatological mess they're making.

Berzin, 40, a chemical engineer, knew a few things about algae: they double their mass in a few hours, produce 30 times as much oil per acre as sunflowers do and thrive in sewage or brackish water. Most important, they devour carbon dioxide, the primary culprit in global warming. Grow the stuff like a crop, and you could use it both to produce biofuel and to pull a key greenhouse gas out of the sky. In 2001, Berzin founded GreenFuel Technologies in Cambridge, Mass., to do just that. By 2007 he had algae growing at the Redhawk power plant near Phoenix, with pipes from the smokestacks running into his greenhouses, where the algae gobbled up the CO2. He is now working with a national lab to make jet fuel from his green slime.

Berzin is one of thousands of innovators reinventing the $6 trillion energy business. In Israel, where he was educated and raised, biblical metaphors come naturally to mind. Berzin points out that God first appeared to Moses as a bush that was burned but not consumed. "What can you burn without consuming it?" Berzin asks. "Renewable fuels."

Krupp is president of the New York City-based Environmental Defense Fund