If you have the natural gas. Natural gas is a great shaping source. Complementary to nukes, coal, renewables alike. Not exactly low carbon though. (Conventional is lower than coal. But conventional natural gas reserves are running out. Frakking aside from being horrible environmentally, leaks methane and cause GHG emissions comparable to coal. Shale gas leaks methane and is environmentally destructive. Shipping LNG or CNG overseas is can lead to accidents and regardless leaks methane. Methane is a far worse GHG than CO2.)
Lets do a risk comparison. Do nothing keep using fossil fuels, catastrophe. Try a nuclear path. Expensive, same risk of being aborted by poltiics, same risk of running out of money. Same risk of plain old not working, cause nuclear is lousy for peaking and demand response - two things you need even in the absence of renewables. Or a renewable path. It is not certain disaster like sticking with fossil fuels. Once started I'd say the risk of it failing for various reasons is lower than with nuclear. And you don't have all the freaking nuclear disasters, which I consider worth something.
Barry Commoner advocated switching immediately to natural gas and efficiency with a slow transition to solar back in the 70s when we had plenty of conventional natural gas. If he had been listened to then, we would have had a no risk option.
We don't have that. We have no low risk options. A renewable path (which is not a particularly soft energy path) is the lowest remaining risk. Also some of the mineral shortages: they are assuming one hell of a lot of electric cars. If we move to electric trains that would save some of the minerals. We do have substitutes when it comes to building wind generators. We can replace some of the fancy rotor that use rare earths with slighly less efficient ones that use iron. At least Jacobson and Delucchi base their proposals almost entirely on existing tech. Hansen wants to gamble on tech for which commercial prototypes have not been demonstrated. The equivalent would be for J & D to have based their proposal on flying energy generators. -- Facebook: Gar Lipow Twitter: GarLipow Grist Blog: http://www.grist.org/member/1598 Static page: http://www.nohairshirts.com