Climate change activists gathered in New York’s Times Square on Earth Day to call for action on global warming and a reduction in plastics consumption, as volunteers around the world planted trees and cleaned up rubbish to commemorate the 54th annual environmental event.

This year’s Earth Day, which falls on Saturday, comes after weeks of extreme weather, with temperatures reaching record highs in Thailand and a brutal heatwave in India, where at least 13 people died of heatstroke at a ceremony last weekend.

Average global temperatures could hit all-time highs in 2023 or 2024, climate scientists have warned.

Pope Francis, who has championed green causes since his election in 2013, urged people to look after the environment.

“The Book of Genesis tells us that the Lord entrusted human beings with the responsibility of being stewards of creation (Gen 2:15). Care for the Earth, then, is a moral obligation for all men and women as children of God #EarthDay,” he tweeted on Saturday.

“Climate impacts are here,” Areeba Hamid, co-executive director of Greenpeace UK, said on Friday as climate change activists walked down the street outside parliament in London, some dressed in green costumes and green paint.

Hamid said when she now visits her hometown of Delhi, it feels like “putting your head in the oven” and that London’s 2022 heatwave was like “a dystopian film”.

“We can’t afford that anymore.”

Activists led by the Extinction Rebellion group have gathered in London to kick off a four-day action, billed “The Big One”, to coincide with Earth Day.

About 30,000 people have signed up for family-friendly rallies and marches, marking a change in strategy for a group known for its disruptive tactics, including blocking roads, throwing paint and smashing windows.