The goals throughout aviation history were/are: 1.) Further / Faster / Higher. 2.) Improved Economics. 3.) Sustainability. Aviation is growing quity steadily with 5 % per year, but self-set goals by various aviation organizations to limit carbon emissions are unlikely to be met (in 2020, in 2050, ...) and carbon offset schemes will not be fully in place in 2020. Carbon offset schemes only make limited sense and are debatable. Unconventional aircraft configurations (here: BWA, BWB) do not show an overall benefit and will not be a solutions to aviation‘s future. Conventional configurations questioning established design rules and requirements show much potential! It is important to come early to a conclusion about which aviation fuels should be used together (not just one) to meet demand. Candidates are: a) remaining fossile kerosene, b) hydrogen, c) drop in fuel from Power-to-Liquid.
Hamburg Aerospace Lecture Series --- Collection of Presentations --- http://www.AeroLectures.de