'We're not through': After biggest climate protest in history draws 4 million worldwide, campaigners prepare for week of action

"September 20th was a demonstration of intent, of 4 million people who took time off from work or school to say that they are ready to move on and make the changes we need."

As organizers behind Friday's Global Climate Strike reported that four million children and adults attended marches and rallies all over the world—making it the biggest climate protest ever—they assured leaders who have been reticent to take bold climate action that the campaigners' work is far from over.

The Global Climate Strike was just the first day in a week of public actions ahead of the U.N. Climate Action Summit.

On Saturday, the group shared images of more demonstrations being held in countries including Kenya, France, and Indonesia.

Young climate action leaders who helped to bring the Global Climate Strike to fruition are gathering Saturday at the U.N. in New York for a historic Youth Climate Summit. Sixteen-year-old Greta Thunberg, who held the first one-person climate strike a year ago in Sweden; 17-year-old Xiye Bastida, and 14-year-old Alexandria Villaseñor will speak at the event.

As world leaders attend the U.N. Climate Action Summit on Monday, campaigners are planning dozens of events for the coming week to demand concrete action from policymakers to begin a rapid shift to a renewable energy economy.

350.org, one of the organizations behind the Global Climate Strike, reported late Friday that in the U.S. alone, 600,000 people—or two percent of the population—attended actions in their communities to kick off the week of action. An estimated 300,000 attended the strike in New York City.

Strikes were held in 185 countries, with 1.4 million walking out of their workplaces and classrooms across Germany and 330,000 attending actions all over Australia.

"Today we saw a movement, made up of people from all ages and backgrounds coming together and calling for the end of coal, oil, and gas," said May Boeve, executive director of 350.org. "September 20th was a demonstration of intent, of 4 million people who took time off from work or school to say that they are ready. Ready to move on and make the changes we need for a future free from fossil fuels and based in climate equity and justice."

"Today's demonstrations mark the beginning of a global mobilization which will span until next Friday, September 27th," Boeve added.