President Trump on Tuesday dismissed the “perennial prophets of doom” on climate change before an audience that included Swedish activist Greta Thunberg at the World Economic Forum in Davos, Switzerland.

But the president said he was a “big believer in the environment” and announced that the US will join the “One Trillion Trees” initiative supported by the forum in an effort to offset carbon emissions.

“We’re committed to conserving the majesty of God’s creation and the natural beauty of our world,” Trump told the world’s top business and political leaders.

He added, to sustained applause, that the US “will continue to show strong leadership in restoring, growing and better managing our trees and our forests.”

But he also lashed out at “alarmists” — the “perennial prophets of doom and their predictions of the apocalypse” — though he didn’t explicitly mention climate change, which is a major theme, along with sustainability, in this year’s annual forum.

Trump and Thunberg also did not mention each other directly Tuesday, but his remarks stood in stark contrast to the 17-year-old’s renewed call to “start listening to the science” on climate change.

Just as Trump was arriving in Davos, she said Tuesday that the world needs to “treat this crisis with the importance it deserves.”

The president, who has pulled the US out of the 2015 Paris climate accord, has traded barbs with Thunberg on social media.

Thunberg accused leaders of “cheating and fiddling around with numbers” with talk of cutting emissions to “net zero,” or emitting no more carbon than is absorbed by the planet or technical means, by 2050.

“Without treating it as a real crisis, we cannot solve it,” Thunberg said, adding that it was time to stop burning fossil fuels immediately, not decades from now.

She cited a report released in 2018 by the UN science panel that calculated the amount of additional carbon dioxide the atmosphere can absorb before global average temperature hikes exceed 2.7 degrees Fahrenheit.

Leaders agreed to try to stay below that threshold when they signed the Paris accord, but scientists warn the chances of doing so are dwindling.

Responding to those who have accused her of doom-mongering, Thunberg insisted that her message was based on scientific facts, not irrational fears.

“My generation will not give up without a fight,” she proclaimed.

The Swedish teen shot to fame by staging a regular strike at her school, sparking a global movement that eventually earned her Time magazine’s award as the 2019 Person of the Year.

Last year, she told leaders gathered in Davos that they should “panic” about climate change.

“I don’t want your hope. I don’t want you to be hopeful. I want you to panic. I want you to feel the fear I feel every day. And then I want you to act,” she said last year.

Speaking Tuesday afternoon, Thunberg brushed aside Trump’s announcement that the US would join the forum’s initiative to plant 1 trillion trees across the world to help capture carbon dioxide from the atmosphere.

“Planting trees is good, of course, but it’s nowhere near enough. … It cannot replace mitigation,” Thunberg added, referring to efforts to drastically cut emissions in the near term.

With Post wires