Just days before 120 world leaders, including President Obama, UK Prime Minister David Cameron, and French President Francois Hollande, convene for the United Nations Climate Summit, more than 400,000 people took to the streets of New York City — demanding action against climate change.

The People’s Climate March began at around 11:30 am and, at times, participants stretched at least four miles, carrying banners, posters, and other props calling for world-wide environmental action on global warming. By 5 pm, organizers had to text marchers, asking them to disperse from the route because the crowds had surpassed capacity.

“Today I march because I want to behold a brighter future,” said Stanley Sturgill, a retired coal miner from Kentucky who is suffering from black lung, at a press conference before the march. “We have destroyed our health and I’m here because our political leaders have failed us. We know together we can build our bright future.”

The UN Secretary-General Ban Ki-moon made an appearance at the march, along with NYC Mayor Bill de Blasio, actors Edward Norton and Leonardo DiCaprio, former Vice President Al Gore, Senators Sheldon Whitehouse (D-RI), Bernie Sanders (I-VT), Chuck Schumer (D-NY), and Representatives Keith Ellison (D-MN), Nydia Velazquez (D-NY), and Jerrold Nadler (D-NY).

Almost every labor union, including the Service Employees International Union — the largest in the city, participated, as did several religious organizations, marijuana farmers from across the country, and even some Republicans.

D.R. Tucker, a conservative blogger and freelance writer, attended the march with Citizens’ Climate Lobby, reported the International Business Times.

“We want Congress to take a market-based approach to capping carbon emissions,” said Tucker. “A lot of Republicans are saying privately that this is a good idea, but they need that nudge. I think this march will give them that nudge.”

Hopefully nearly half a million people peacefully protesting in the streets will not just give the GOP that nudge, but it will give them the good, hard shove that they need. It’s time for all world leaders admit that climate change is real, that it is man-made, and that if something isn’t done soon, the Earth and everyone on it is in real trouble.