Prahalad cites Calera, a California firm in which venture capitalist Vinod Khosla is investing.

FORBES: Thought Leaders

The Calera cycle would reverse the usual effect of cementmaking, which is to spew CO2 into the air.

FORBES: Thought Leaders

While it remains to be seen if Calera can produce cement strong enough to be useful in construction, the company is toying with a radical business model: It will give away cement while charging polluters a fee for removing their emissions.

FORBES: Thought Leaders