A barefoot Duke of Sussex reportedly stood before an elite audience of business leaders and celebrities gathered at Google’s annual deluxe retreat in Sicily on Wednesday evening to warn immediate action is needed to avoid an approaching climate catastrophe.

The Evening Standard reports Prince Harry, 34, is understood to have insisted the future of the planet is a humanitarian issue, not a political one, and the world must act to avoid disaster.

The prince has already announced he and his wife, the Duchess of Sussex Meghan Markle, will have no more than two children because of the concerns they share for the environment.

The venue chosen for his latest cautionary tale was the Sicilian seaside at a billionaire’s-only party dubbed Google Summer Camp.

Traditionally held every year at the end of July, the famed Verdura Resort hosts the top-secret gathering, with the three-day summer camp costing the tech giant some $20 million, as Breitbart News reported.

According to the Standard, the man who is sixth in line to the throne believes the way mankind is living is having a devastating impact on the world, and humanity has been “far too slow” in waking up to the issue.

Prince Harry has been keen to push his credentials on environmental matters, choosing an interview in the September issue of Vogue, guest edited by his wife the Duchess of Sussex, to speak about the the “terrifying” effects of climate change, saying: “What we need to remind everybody is: these are things that are happening now. We are already living in it… Which is terrifying.”

Prince Harry has praised his father in the past for his work on the environment and trying to influence people to act to save the planet.

Earlier this month the Prince of Wales warned global leaders that if we don’t tackle climate change in 18 months the human race will become extinct.

In a speech in London to foreign ministers from the Commonwealth, the man who will be King said:

I am firmly of the view that the next 18 months will decide our ability to keep climate change to survivable levels and to restore nature to the equilibrium we need for our survival.

For his part, Prince Harry’s audience would have been aware of the challenges he warned against.

Many of the guests Verdura Resort, including former U.S. President Barack Obama and Leonardo DiCaprio— who has his own climate change foundation — have described global warming as the biggest threat to future generations.

They are also used to travelling in some style to an event that has been described as “Davos by the Sea.”

Forbes reports numerous yachts are currently moored off the beach at Verdura Resort having discharged their passengers; German pharmaceutical titan Udo J. Vetter’s sailing yacht Aquarius, Barry Diller and Diane Von Furstenberg’s sailing yacht EOS, Graeme Hart’s yacht Ulysses with others en route including David Geffen’s yacht Rising Sun, Google’s Eric Schmidt’s yacht Infinity and its support vessel Intrepid, among them.

According to Italian press reports, the attendees showed up in 114 private jets.

One report found that 114 flights from Los Angeles to Palermo, Italy, where guests landed, would spew an estimated 100,000 kilograms of CO2 into the air.