Greta Thunberg makes a surprise appearance at the Glastonbury Festival | Greta Thunberg

Greta Thunberg has warned the world faces a ‘total natural disaster’ unless citizens take urgent action as she makes a surprise appearance at the Glastonbury Festival.

The 19-year-old activist led chants of “climate…justice” after delivering a rousing speech from the Pyramid stage that painted an apocalyptic picture of the planet’s future.

To the cheers of thousands of festival-goers, Thunberg said: “We are nearing the precipice and I would strongly suggest anyone who hasn’t been greenwashed yet stay put.

“Don’t let them pull us any closer to the edge. It is at this moment that we hold our position.

Thunberg was introduced on stage by Glastonbury co-host Emily Eavis, who described the Swedish teenager as “the most inspiring speaker of this generation”.

Drawing cheers of approval, Thunberg blamed world leaders for failing to end the climate emergency and for creating “loopholes” that allow ecological destruction to go unchecked.

“It hasn’t just become acceptable for leaders to lie – it’s almost what we expect of them,” she said to applause.

She said it was time for society to start “creating hope” rather than waiting for it to happen: “Hope is not something that is given to you. It is something something you have to earn, create. It cannot be passively earned by sitting passively and waiting for someone else to do something.

“He takes action. It’s getting out of your comfort zone. And if a group of school kids were able to take millions of people to the streets and start changing their lives, imagine what we could all do together if we tried.

Thunberg’s surprise in-person speech was announced Saturday morning. She appeared shortly before a set by American pop band Haim and just hours before the main track by Paul McCartney.

In the scorching sun on day four of Glastonbury, Thunberg urged festival-goers to “do what seems impossible” by helping to stop global warming before it’s too late.

She added: “These crises are the biggest story in the world. And it must be spoken as far and as widely as possible, as far as our voices can carry and even further.

“It must be said in articles, newspapers, films and songs; at breakfast tables, at lunch meetings, at family gatherings; in elevators and bus stops; and in rural shops… and music festivals like Glastonbury.

Thunberg is the festival’s second high-profile speech after Ukrainian President Volodymyr Zelenskiy delivered a video address to thousands of cloudy-eyed revelers on Friday morning.

Zelenskiy described Glastonbury as the “greatest concentration of freedom” in the world as he urged campers to lobby politicians to end the war in Ukraine.

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To the cheers of the crowd, he said, “We in Ukraine would also like to live life as before and enjoy the freedom and this wonderful summer. But we can’t do that because the most terrible thing happened: Russia stole our peace.

Founded in 1970 with the aim of building support for the campaign for nuclear disarmament, Glastonbury has retained its strong political focus over the past half-century, even as the festival has expanded to a much wider audience.

Jan G. Gilbert