The environmental implications of using coal are bordering on horrific, considering how much the military will be using. Nuclear isn't the magical solution some imagine, as uranium is also a finite resource and has already doubled in cost in the last decade. Here's a good article concerning the impending shortages of jet fuel, if I may post it: http://www.associatedcontent.com/article/3018604/aviation_after_peak_oil_is_there_a.html?cat=15