1. Coal's share of world energy demand at highest since 1970;Bakhsh,2014
2. BP energy outlook 2035;BP,2014
3. Global transport outlook to 2050: targets and scenarios for a low-carbon transport sector;Dulac,2012
4. World population projected to reach 9.6 billion by 2050;Affairs DoEaS,2013
5. 50 by 50: global fuel economy initiative;Watson,2009