Each new source of energy has its drawbacks and limitations. The underlying issue is sustainability. We are using up everything faster than it can be replenished. There are just plain too many people on the earth and we--not each of us, but all of us together--have too great an appetite for resources for our Mother to support us in harmonious perpetuity. Until we achieve aggressive negative population growth and dramatically reduce our appetites we are only postponing the inevitable by relying on alternative energy and material sources to "save" us.