While the "need" to decarbonize is debatable, this article, The End of Magical Climate Thinking from Foreign Policy is one of the best I have read about what has gone wrong with alternative energy. As indicated in the "Picken's Plan" post, the problem is technological -- alternative energy just doesn't come close to traditional sources in cost or energy yielded. The authors get it exactly right when they say,
The real technological obstacles to decarbonizing the global economy today represent an insurmountable obstacle to political efforts to limit carbon emissions. Until policymakers get serious about addressing the central technological challenge, all efforts to control carbon emissions are doomed.