The Duke of Cambridge has said humanity needs to "fundamentally reset our relationship with nature and our trajectory as a species" to avoid climate disaster.
In a video message played at a gala for US-based charity Conservation International, Prince William said the next decade would be "one of our greatest ever tests".
He warned the most vulnerable people around the world, "and those who have done the least to cause climate change", would be impacted the most.
William urged those present to take their lead from the millions of young people who are booking for solutions to the problem.
"All of us, across all sectors of society, and in every corner of the globe, must come together to fundamentally reset our relationship with nature and our trajectory as a species," he said.
"I truly believe that humans have an extraordinary capacity to set goals and strive to achieve them."
William added: "The remarkable development of the Covid-19 vaccine in record time is a case in point."
In October last year, the duke launched the Earthshot Prize to help those coming up with solutions to climate change scale up their ideas.
The prize's has five goals for the next decade - protect and restore nature, fight air pollution, revive the oceans, build a waste-free world and fix the climate.
The duke told attendees: "We want to find the brightest minds and boldest ideas that will help us to achieve these Earthshots.
"But it will require our collective energy, determination, and optimism to get there."
He added: "Together we must unite every business, every community, every government and every person around our common goal to repair the earth."
William said he hoped people over the world regardless of background or beliefs could "join this shared optimism for the future and conviction that change is truly possible".
"Together, I'm confident that we can begin to heal our planet, protect nature, and improve lives for billions of people, today and for generations to come," he said.
