William, heir to throne, set up the prize in 2020 with the mission of finding solutions to the planet’s biggest environmental problems through new technologies and ideas.

Ardern joins Earthshot’s board of trustees as it gears up to select finalists for the 2023 award. Last year, five winners were each awarded 1 million pounds ($1.24 million) at a ceremony in Boston, United States.

Prince William said he was grateful that Ardern, who unexpectedly stepped down as New Zealand’s leader earlier this year, was joining the team.

“Her life-long commitment to supporting sustainable and environmental solutions, along with her experience as Prime Minister of New Zealand, will bring a rich infusion of new thinking to our mission,” he said in a statement on Tuesday.