Protests have taken place around the world calling for action to avert environmental catastrophe.

From London to Sydney, here’s a look at some of the millions of people joining the global youth climate strike.

Climate strikeA ‘polar bear’ joined children from the Terra Nova secondary school in Cheshire to demand action to stop global warming (Peter Byrne/PA)
Climate strikeA protester at Millbank in London held up a poster of climate activist Greta Thunberg (Gareth Fuller/PA)
Climate strikeThousands gathered on the unseasonally hot September day in Victoria Park Gardens to warn against global warming (Jonathan Brady/PA)
Climate strikeA younger protester needed a lie-down as handmade posters warned of the need to tackle climate change (Gareth Fuller/PA)
Climate strikeStudents at a large protest in Manchester expressed their anger at Donald Trump (Peter Byrne/PA)
Climate strikeThere was a big turn-out at the protest in Cambridge (Joe Giddens/PA)
Climate strikeProtesters in the city later held a ‘die-in’ to warn about the threat to the planet (Joe Giddens/PA)
Climate strikeYoung and old also took to the streets of Birmingham (Jacob King/PA)
Climate strikeProtesters in Cullercoats, Tyneside, staged their protest at the seaside (Owen Humphreys/PA)
Climate strikePupils from Colaiste Bride School made their point with striking posters at a protest in Dublin (Brian Lawless/PA)
Philippines Climate ProtestsThousands of miles away in the Philippines, activists displayed their message in front of ‘a human globe’ formation (Bullit Marquez/AP)
South Korea Climate ProtestsSouth Korean protesters held portable LED lamps to show the need for renewable energy (Lee Jin-man/AP)
India Climate ProtestsIn India, young protesters gathered outside the Ministry of Housing and Urban Affairs in New Delhi (Manish Swarup/AP)
Germany Climate ProtestsActivists blocked a road in Frankfurt, Germany, during rush hour (Michael Probst/AP)
Australia Climate ProtestA large inflatable globe was bounced through the crowd as thousands protested in Sydeny (Rick Rycroft/AP)