Beginning April 15, protesters with Extinction Rebellion took to the streets of London and other cities to demand governments declare a climate and ecological emergency. They occupied key spots in the city, calling on those in charge to reduce greenhouse gas emissions to zero by 2025, halt biodiversity loss and set up citizens' assemblies on climate and ecological justice.

Extinction Rebellion, founded last year by academics in the United Kingdom, is one of the world's fastest-growing environmental movements. Their aim is to protest climate change inaction in a creative and nonviolent way. Demonstrators say people are causing their own mass extinction, which is the basis of their "rebellion."

Harry and Meghan, the duke and duchess of Sussex, didn't exactly take part in the sit-in on London's Waterloo Bridge on April 18. The royals are expecting and protesters used the happy event in their demonstration, having the couple "thank" Extinction Rebellion for saving their child's future.

Activists have used a variety of unusual protest methods to draw maximum attention and get their point across. Throughout the week, they've blocked traffic, climbed atop buses and superglued themselves to buildings and, in the case of this young man at London's Canary Wharf station on April 17, trains.

The goal of the protests is to temporarily disrupt everyday life. As a result, police have arrested more than 800 people in London alone. Activists want to get the public on their side, but a YouGov survey showed that just 36% of more than 3,500 British polled support the protest, with 52% against.

Extinction Rebellion protesters first attracted global attention on April 1, during yet another heated Brexit debate in the British Parliament. A group of semi-naked activists revealed themselves in the visitor gallery with slogans including "SOS" and "Stop Wasting Time" written on their bodies, with some gluing their hands to a glass barrier. The scene was quickly broken up my security.

The Extinction Rebellion protests got their start in London, but the movement has also spread to other major cities around the world. On April 15, these activists on the Oberbaum Bridge in Berlin blocked traffic for hours.

On April 21, organizers in London said they were willing to switch tactics and talk with the government. "We're giving them an opportunity now to come and speak to us," said spokesman James Fox. "If they refuse … then this is going to continue and this going to escalate in different, diverse and very creative ways."