SAN LUIS OBISPO, Calif. (MarketWatch) — Billionaire capitalists saving the Earth? You bet. While environmentalists regularly accuse giant capitalist entities like ExxonMobil, Cargill, Koch, Massey and others of depleting nonrenewable energy and other natural resources, a new enlightened class of capitalists is betting new space-age technologies will discover and restore resources and make them a fortune while saving the world from a disastrous ending.