An estimated ten thousand students took to the freezing cold streets of Berlin, Germany on Friday as they added their voices to the growing youth-led global uprising that is demanding urgent and far-reaching action to address the world's climate crisis.

Following others using the #ClimateStrike tactic inspired by 16-year-old activist Greta Thunberg of Sweden, the #FridaysforFuture march in Berlin was held as students across Switzerland also held protests on Friday and two days after 35,000 young people marched in Brussels.

The students in Germany marched to the Ministry of Economics where a conference focused on the country's coal industry was being held. Outside the building they called on the nation's leaders to phase out coal immediately.

"The general problem is not that there's a lack of knowledge, but of action," one student demonstrator told Deutsche Welle. "That's why it's good to go into the streets and express our views."

Thousands of students, ranging in age from elementary school to college, were seen dancing and jumping in unison as they—like their allies elsewhere around the world—called on elected leaders, business executives, and older generations to mobilize for urgent action to address the crisis:

Photos of the crowd:

From the elite gathering of the World Economic Form in Davos, Switzerland on Friday, Thunberg—widely credited with spurring the European movement over recent months—sent her applause and gratitude, via numerous messages and retweets on her Twitter account, to those who demonstrated in Berlin and elsewhere. And from Davos, she repeated her call for urgent mobilization by telling the world that "action" not "hope" is what the rapidly warming world needs most.

"I want you to act as you would in a crisis," Thunberg told attendees at Davos and those watching around the world. "I want you to act as if our house is on fire. Because it is."