Popular Mechanics offers a terrific comparison study of alternative fuels, written from a somewhat daring perspective:
In the lab, many gasoline alternatives look good. Out on the road, automotive engineers have a lot of work to do, and energy companies have new infrastructure to build, before very many people can drive off into a petroleum-free future. And, there's the issue of money. Too often, discussions of alternative energy take place in an alternative universe where prices do not matter.Last I checked, this "alternative universe" is capitalism, where costs matter - or don't matter - depending on their political implications. During America's westward expansion, "experts" explained to prospective homesteaders that there was no reason not to relocate to an arid basin with .05 inches of rainfall per year, because "rain follows the plow." Arguments to the contrary were correct, of course, but they were also pessimistic. And as we all know, it's much better in our culture to be wrong for the right reasons than right for the wrong ones.
But enough about that. Suppose that for some bizarre reason, we wanted to replace oil with ethanol:
One acre of corn can produce 300 gal. of ethanol per growing season. So, in order to replace that 200 billion gal. of petroleum products, American farmers would need to dedicate 675 million acres, or 71 percent of the nation's 938 million acres of farmland, to growing feedstock.It'd be crazy to do that, of course. Fortunately, there are plenty of poor countries whose existing farms and rainforests could easily be turned over to the production of ethanol for export.
Overall, PM's conclusion is that alternative fuels are a dubious proposition. Thus, they favor about the only thing you can favor: Pursuing as many research and conservation strategies as possible, while hoping desperately that someone comes up with a breakthrough before the more inconvenient effects of peak oil manifest themselves.
As for peak copper, I'm not so worried. I've got a big jar of pennies at home.