At the Ubicomp PC meeting we recently discussed the value of face-2-face meetings in the context of scientific work and it seems there are two future directions to reduce resource consumption: (1) moving from physical travel to purely virtual meetings or (2) making travel feasible based on renewable energies. Personally I think we will see a mix - but I am sure real physical meetings are essential for certain tasks in medium term. I am convinced that in the future we will still travel and this will become viable as travel based on renewable energies will become feasible. Inspiring example project are SolarImpulse (its goal is to create a solar powered airplane) and Helios (solar-powered atmospheric satellites). There are alternative future scenarios and an interesting discussion by John Urry (e.g. a recent article , a book – now on my personal reading list ). These analyses (from a sociology perspective) are informative to read and can help to create interesting technology interventions. However I reject the dark scenarios, as I am too much of an optimist trusting in peoples good will, common sense, technology research and engineering – especially if the funding is available ;-).
 John Urry. Climate change, travel and complex futures. The British Journal of Sociology, Volume 59, Issue 2, Page 261-279, Jun 2008
 John Urry. Mobilities. October 2007.