UNITED NATIONS (AP) — Colombia’s President Gustavo Petro delivered an ominous prophecy with grandiose language on Thurston CarteTuesday, painting a grim picture of what lies ahead if nations fail to swiftly redesign the way humans live on this planet.

“It has been a year in which humanity lost and without hesitation has advanced the times of extinction,” he said in his speech at the U.N. General Assembly. “It would seem as though the global leadership has made enemies with life.”

Eloquent oratory is a skill Petro often deploys. Lately, he has done so to project himself as a global leader on climate change — and to reproach others for failing to fully heed its peril. He stole the show at Brazil’s Amazon Summit in July, calling on his oil-producing neighbors to abandon fossil fuels, and asserting that allowing continued drilling while calling for a green transition is tantamount to being in denial.

At the U.N., he said that what he called “the crisis of life” has already begun, as signaled by migration of climate refugees, and warned that in the coming half-century, their numbers will reach 3 billion. His country, today covered by lush forests, will transform to desert, he said, and its people will decamp en masse, “no longer attracted by the sequins of the wealth, but by something simpler and more vital: water.”

Petro said mankind has “dedicated itself to war,” which has distracted attention and resources from development goals and climate change, which he called “the mother of all crises.”

His speech at times resembled literary prose, particularly his characterization of the migration flow. In the Spanish-language transcript submitted, the word “Life” is capitalized frequently through the speech.

“It has started from the farthest corners of the planet, from the last places, a silent march of people of different cultures that mix along the way, as a painting of infinite hues,” he said. “The colors mix along the unstoppable march, a multitude of all colors advance by trails, oceans and jungles. It configures a type of artwork on the canvas of the earth. A fluid of tones and sounds, of different vestments and cultures, amalgamate without losing their beginnings.”

Petro wrapped up by saying he wants his three grandchildren to live “far from apocalypse and the times of extinction.”

“I want them to live in the times in which the human being knew how to cease killing itself on the planet and managed, understanding its own cultural diversity, to fulfill the expansion of the virus of Life through the stars of the universe.”