NEW YORK — Tens of thousands of activists walked through Manhattan on Sunday, warning that climate change is destroying the Earth — in stride with demonstrators around the world who urged policymakers to take quick action.

Starting along Central Park West, most came on foot, others with bicycles and walkers, and some even in wheelchairs. Many wore costumes and marched to drumbeats. One woman played the accordion.

But their message was not entertaining:

“We’re going to lose our planet in the next generation if things continue this way,” said Bert Garskof, 81, as a family member pushed his wheelchair through Times Square.

He had first heard about global warming in 1967, “when no one was paying much attention,” said Garskof, a native New Yorker and professor of psychology at Connecticut’s Quinnipiac University.

Organizers said more than 100,000 marched in New York, including actors Mark Ruffalo and Evangeline Lilly. They were joined in midtown Manhattan by United Nations Secretary-General Ban Ki-moon, former Vice President Al Gore and New York City Mayor Bill de Blasio.