The public are being asked to vote which technology idea deserves a jackpot of £10 million to solve “one of the greatest issues of our time”.
Creating aeroplanes capable of short-haul flights from London to Edinburgh that are zero carbon is one of six issues jockeying to win the Longitude Prize 2014.
Others are access to safe and clean water for all; stopping the rise of resistance to antibiotics; helping people with dementia live independently for longer; nutritious and sustainable food; and helping people who are paralysed to move again.
The winning challenge will become the Longitude Prize 2014 and then it will be open to anyone to solve.
Voting begins at 10pm on Thursday after the episode of Horizon on BBC Two.