Climate protesters disrupting cities is called Extinction Rebellion

London — Extinction Rebellion, the more radical arm of the climate-change protest movement, on Monday kicked off two weeks of planned protests designed to shut down dozens of cities around the world.

Demonstrators blocked roads and bridges leading to the Palace of Westminster in central London. They staged a “die-in” in Wellington, New Zealand. They obstructed a major roundabout in Berlin, parked a pink sailing boat outside of the prime minister’s office in Dublin and splattered fake blood on Wall Street’s “Charging Bull” sculpture.

The group’s message is that climate change is an emergency that requires drastic and immediate action. They have already seen some success.

“Extinction Rebellion is widely credited with accelerating policy change in the U.K.,” said Robert Falkner, a fellow at Chatham House, a think tank.

But their tactics test public tolerance for social and economic disruption. Some say their specific demands are wildly unrealistic.

New Zealand Prime Minister Jacinda Ardern said on Monday people were free to protest “but in blocking people from being able to go and do their day-to-day job doesn’t necessarily take us any closer to the climate action they are calling for.”

By early evening in London, police said they had arrested 217 demonstrators. The last time Extinction Rebellion staged a protest on this scale, in April, more than 1,000 people were arrested in a police operation that cost nearly $20 million.

London Mayor Sadiq Khan conceded “bolder action” is needed to take on climate change, but he criticized the movement for potentially overwhelming an already stretched police force.

Anticipating police frustration, protester Paul Stephens, a 55-year-old retired detective sergeant, stood outside Metropolitan Police headquarters on Monday morning handing out fliers to officers.

“From their perspective, it’s a waste of time; from our perspective, it’s not,” he said, explaining the strategy was to “create a dilemma for the police” so they either had to allow the demonstrations to continue or arrest 1,000 “otherwise law-abiding people” for committing low-level offenses.

The protesters are walking a tightrope — they want to spark enough disruption to effect change but not so much they alienate the public.

Extinction Rebellion has grown in parallel to the climate strike protests inspired by teenage Swedish activist Greta Thunberg. But Extinction Rebellion includes not just schoolchildren — it has attracted young professionals, parents, grannies and others concerned about climate change and habitat loss.