The overall winners will be announced at the fifth Earthshot Prize awards in the Brazilian capital Rio de Janeiro on Wednesday 5 November.
The 2025 event marks the halfway point in the Earthshot decade, with Prince William pointing out that at the time of its launch in 2020, scientists made clear significant changes had to be made by 2030.
“Back then, a decade felt a long time. George was seven, Charlotte five and Louis two; the thought of them in 2030 felt a lifetime away,” the Prince of Wales said in a video message posted on social media.
“But today, as we stand halfway through this critical decade, 2030 feels very real.
“The Earthshot Prize was founded because this decade matters. 2030 is a threshold by which future generations will judge us; it is the point at which our actions, or lack of them, will have shaped forever the trajectory of our planet.”