Prince William announced the five winners for his prestigious Earthshot Prize.
The annual awards, presented at a ceremony in Boston in the US on Friday, were created by the Prince of Wales to fund projects that aim to save the planet.
Each winner will receive £1m ($1.2m) to develop their innovation.
The winning projects are based in Kenya, India, Australia, the UK and Oman.
This year's winners were chosen from a list of 15 finalists by a panel that includes Prince William, Sir David Attenborough, actress Cate Blanchett, footballer Dani Alves, Fijian activist Ernest Gibson and singer Shakira.