Fifteen innovative ideas are in the running for the environmental competition, with five winners - due to be announced in Boston in the US next month - set to receive £1million each to develop their projects.
Cop26 has been billed as the last best chance to keep global temperature rises to no more than 1.5C, with Sir David critical of those who deny the climate crisis.
A restorative ecosystem scheme in Costa Rica, a tool that creates fuel from waste and a green hydrogen technology have been named winners of Prince William's sustainable design competition, Earthshot Prize and will each receive a medal designed by Christien Meindertsma.