WASHINGTON — Students across a warming globe pleaded for their lives, future and planet Friday, demanding tough action on climate change.

From the South Pacific to the edge of the Arctic Circle, students in more than 100 countries walked out of classes to protest what they see as the failures by their governments.

Well over 150,000 students and adults who were mobilized by word of mouth and social media protested in Europe, according to police estimates. But the turnout in the United States did not look quite as high.

“Borders, languages and religions do not separate us,” 8-year-old Havana Chapman-Edwards, who calls herself the tiny diplomat, told hundreds of protesters at the U.S. Capitol. “Today we are telling the truth and we do not take no for an answer.”

Thousands of New York City students protested at locations including the American Museum of Natural History and a football field . A police spokesman said there were arrests, but he did not know how many.

The coordinated “school strikes” were inspired by 16-year-old Swedish activist Greta Thunberg, who began holding solitary demonstrations outside the Swedish parliament last year.

Since then, the weekly protests have snowballed from a handful of cities to hundreds, fueled by dramatic headlines about the impact of climate change during the students’ lifetime. Unless emissions of heat-trapping gases start dropping dramatically, scientists estimate that the protesters will be in their 40s and 50s, maybe even their 30s, when the world will reach dangerous levels of warming that international agreements are trying to prevent.

Thunberg, who has been nominated for the Nobel Peace Prize, said the world faces “the biggest crisis humanity ever has faced, and still it has been ignored for decades.”