An "opening ceremony" Sunday evening attracted hundreds of people to central London, where plans are in place to shut down key sites including Westminster and Lambeth bridges, in addition to protests outside key government departments.
In London, police arrested at least 20 people Monday as protesters have vowed to close down Parliament and Trafalgar Square.
Maud, also an Environmental Science student at Wageningen University, chose her study direction because she's "always been interested in how we treat the planet and humans' impact on the planet", the 19-year-old student said.
Richard Dyer, a retired doctor from Scotland who was taking part in the protests, said he regarded it as an extension of his medical career because climate change was the biggest threat yet to public health.
In Spain, a few dozen activists briefly chained themselves to each other and to an elevated road over a major artery in Madrid, snarling traffic during the morning rush hour.
Video of the raid, which shows police using a battering ram to break into a south London building, quickly went viral Saturday as activists and British lawmakers expressed alarm at the aggressive tactic.
In Sydney several hundred protesters staged a sit-in on a busy road in the Australian capital.
Extinction Rebellion wants to achieve net zero carbon emissions by 2025.
About 30 climate protesters were arrested, Extinction Rebellion said after the climate action group pledged to engage in civil disobedience in Wellington, New Zealand. The Metropolitan Police said 135 arrests had been made by early afternoon.
Similar demonstrations were taking place in Berlin, Sydney, Amsterdam and Madrid on Monday, and organizers said more were expected in up to 60 cities around the world, including NY and Washington, D.C., as part of what they called an "international rebellion".
A second group of protesters gradually formed on the square behind the museum, saying that those who remained on the street were determined to stay until they were arrested.
Another 300 people blocked Berlin's central Potsdamer Platz, placing couches, tables, chairs and flowerpots on the road. The government is now in the process of passing a climate protection law and a climate package, which many activists say is not ambitious enough.
Police say they arrested some of the protesters on the road outside the Rijksmuseum, one of the city's most popular tourist draws.
Reporter Mattijs van de Wiel told NOS that the arrests happened without any form of violence. There are also lane obstructions Monday on Gorge Road West for two blocks between Tillicum Road and Orillia Street, but vehicles will be allowed through.
Protesters also threw red paint on the iconic Charging Bull statue near Wall Street.
German Chancellor Angela Merkel's chief of staff, Helge Braun, criticized Extinction Rebellion's strategies.
But Green Party MP Caroline Lucas - who is backing the protestors - said while they would "cause some disruption", it would be "nothing compared to the chaos" of climate change.
In London, where the Extinction Rebellion movement was born a year ago, demonstrators put up structures on Westminster Bridge in the shadow of Britain's parliament.