She added that the charity was in talks with light bulb manufacturers who had been "fantastic" and trials were planned later this year to try to see "if any of the new light bulbs could be adapted to be suitable".

BBC: Bulb bows out to mixed applause

It would also need completely new engines, rather than adapted existing ones, in order to be sufficiently light and economical.

ECONOMIST: Boeing v Airbus

David Souter, from ICT Development Associates, praised the UNESCO study for linking freedom of expression and privacy rights in the light of a constantly changing Internet in which many people have not adapted their behavior to new privacy threats.

UNESCO: MEDIA SERVICES