Sept. 20 (UPI) -- Sixteen-year-old Swedish environmental activist Greta Thunberg called an elected leaders to pass laws to address climate change as she and millions of people marched across the globe Friday to bring attention to the cause.
Thunberg has become the face of a months-long youth-led effort to hold strikes from school and work to urge action on behalf of the Global Climate Strike.
The teen traveled to the United States to participate in the march and participate in a United Nations Climate Action Summit. She told a crowd at New York City's Battery Park that she met with U.S. lawmakers in Washington, D.C., who "tell us they 'really, really admire what we do,'" yet have done nothing to address the climate crisis."
"We demand a safe future. Is that really too much to ask?"
Thunberg said it's worth it for students around the world to skip school to march against climate change because the environment is "more important."
"Why should we study for a future that is being taken away from us?
"If you belong to that small group of people who feel threatened by us, we have some very bad news for you, because this is only the beginning," she added. "Change is coming whether they like it or not."
Major U.S. cities including Washington, D.C., Boston, Seattle, Minneapolis, Miami, Los Angeles and Denver held events, including New York City, where the U.N. summit is set for Monday. The high-level summit will evaluate plans to reduce greenhouse gas emissions under the Paris climate agreement.
An estimated 1.1 million students were allowed to skip school after the city announced they wouldn't be penalized for missing school if they attended the strike.
Thunberg tweeted that preliminary numbers indicate at least 3 million people people participated globally.
Thousands rallied in San Francisco and Chicago, with Californians calling for House Speaker Nancy Pelosi and Sen. Dianne Feinstein, both Democrats, to back the Green New Deal, a progressive plan to combat climate change championed by Rep. Alexandria Ocasio-Cortez, D-N.Y.
The Illinois chapter of Youth Climate Strike urged Gov. J.B. Pritzker to pass a law requiring the state to have 100 percent clean energy by 2050.
In London, Labor Party leader Jeremy Corbyn spoke before a large crowd about the importance of taking action against climate change.
"The reality is, this planet is destroying itself," Corbyn said. "In the last 50 years, since 1970, 60 percent of animals have been rendered extinct by global warming, by climate change and by grotesque levels of exploitation of natural places."
He also blasted President Donald Trump for pulling the United States out of the Paris Climate Agreement.
"Let's have no more of this hand-holding with Donald Trump," Corbyn said. "Let's quite simply say that we want every country on board on this. Every country signed up on Paris and going a lot farther than that."
Friday's strike was the third Global Climate Strike this year. More than 1.5 million students participated in the first demonstration in March and thousands more people joined the second in May.
Friday's event began in the Pacific Islands, where communities held mass sit-ins and inter-generational dialogues. In Australia, every major city staged marches. Strikers in Nepal opposed government plans to begin seismic tests for hydrocarbon drilling in the Himalayas. Ivory Coast demonstrators protested a proposed coal plant.
The strikes are an offshoot of the Fridays for Future movement, which was started by Greta. Students worldwide participated in strikes from school every Friday to demand their governments solve the climate crisis.
Thunberg is also scheduled to speak at the U.N. summit Monday.
For the two strikes this month, organizers hope to expand their scope to include adult workers.
"Everyone is needed to disrupt business as usual: from sports stars, actors and teachers to food industry workers, psychologists, delivery drivers and everything in between," organizers state on the Global Climate Strike website.
Globally, 72 trade unions and federations are supporting the strikes. New York City's public school system has said it will excuse absences for students that participate. Some in other participating cities, like Miami, will not.
Thunberg arrived in New York City earlier this month for Monday's U.N. event. Opting not to fly, given the carbon emissions of commercial jetliners, she sailed from Europe. The journey took two weeks.
She testified in Congress earlier this week and led a demonstration at New York City's Foley Square on Friday afternoon before attending Monday's climate summit.
"I don't want you to listen to me. I want you to listen to the scientists and I want you to unite behind the science," she told lawmakers Wednesday, at a joint session of the House climate crisis committee and House foreign affairs subcommittee. "And then I want you to take real action."
Protests extended all the way to India, where students carried posters and chanted in the streets.
In Uganda, the Fridays for Future protests involved local government workers, schools, universities and farmers, who are most affected by the droughts in that country.
"Uganda is facing serious frequent droughts every year, our temperatures are rising ... There is uncontrolled deforestation happening, the plastic bag ban is not working, there is negative political response towards climate change issues," Fridays for Future coordinator Sadrach Nirere said. "This must stop."