Making a major push for natural-gas vehicles would add yet another set of mandates and incentives, including the creation of a costly new fueling infrastructure.
The U.S. had tallied more than 750, 000 green jobs in 2006 and is set to add millions more in the next few decades, according to a new report by the U.S. Conference of Mayors and Global Insight, a Boston-based economic research firm.
Others are more ambitious, requiring new construction or even an extensive rebuilding of city infrastructure consider what is needed to add a second set of pipes for a water-reuse system.