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With the goal of disrupting business as usual in the "center of decision-making in the U.S.," hundreds of activists blocked key intersections across downtown Washington, D.C. Monday morning to demand that lawmakers take bold and urgent action to confront the existential climate crisis.

Chanting "We want climate justice now!" and "The planet we love is under attack," demonstrators positioned vans, cars, their bodies—even a sailboat—in the middle of major D.C. streets to shut down rush hour traffic.

With groups of demonstrators targeting multiple intersections and areas throughout the city, law enforcement was busy making arrests and trying to remove both people and vehicles from the streets.

"It's Washington, D.C. The decisions that are made in this town don't just affect the people in the U.S., they affect the globe every day," said Liz Butler, an organizer of the #ShutDownDC action and vice president of organizing and strategic allegiances for Friends of the Earth Action. "I think people around the world are counting on us to be able to stand up in D.C."

The diverse coalition behind the protest is demanding a Green New Deal, a just and rapid transition to 100 percent renewable energy, a complete halt to deforestation by 2030, and more.

The protests come days after millions of people around the world took to the streets Friday for what was described as the largest mass climate demonstration in history.

"Today I am peacefully breaking the law by blockading a downtown D.C. street in solidarity with students worldwide," Mike Tidwell, executive director of the Chesapeake Climate Action Network Action Fund, said in a statement.

"In the United States, through the radically pro-pollution policies of the Trump administration, we are pushing our planet Earth further and further outside of its comfort zone," said Tidwell. "Which means concerned Americans like me must push ourselves further and further outside our own comfort zones in an effort to pressure our leaders to finally solve this crisis."

The #ShutDownDC action was timed to coincide with the United Nations Climate Action Summit on Monday in New York, where leaders from around 60 nations are expected to speak.

"The U.N. Secretary General called this summit today to strengthen the political will of the world's leaders. But the only thing that's stronger in the four years since the Paris Agreement was passed is the yearly rate of global carbon emissions and the volume of public outcry," Kaela Bamberger, an organizer with Extinction Rebellion, said in a statement. "What will it take to reach the ears of those with our future in their hands?"