The five winners:
Mukuru Clean Stoves, Kenya: Stoves are fired by processed biomass made from charcoal, wood and sugarcane instead of solid fuels.
Kheyti, India: Greenhouse-in-a-Box helps small-hold farmers protect their crops from extreme weather and pests.
Notpla, United Kingdom: Natural, bio-degradable plastic made out of seaweed. The company made more than one million takeaway food boxes.
Revive Our Oceans, Australia: A programme that has trained over 60 women in both traditional and digital ocean conservation methods.
44.01, Oman: Turn carbon dioxide into peridotite, a rock that is found in abundance both in Oman and globally. It offers a low-cost and safe alternative to traditional methods of storing carbon.