Leonardo DiCaprio, Mark Ruffalo, Evangeline Lilly and Edward Norton were among the famous faces at Sunday’s large march in New York City calling for world leaders to take action against global climate change.

Thousands of people gathered for the People’s Climate March in Gotham, which started in midtown Manhattan early Sunday. The event’s backers claim that more than 100,000 people, including public officials, scientists, students and activists, were expected to attend the NYC march.

According to reports, other attendees include New York City mayor Bill de Blasio, Al Gore, Sting, UN secretary general Ban Ki-moon and Jane Goodall. The NYC event is one of many marches of its kind scheduled for Sunday around the world. Emma Thompson partook in the London march, which reportedly saw more than 40,000 attendees.

The marches take place ahead of a United Nations summit on Tuesday, during which world leaders are set to discuss climate change. 350.org organized the events with more than 1,000 environmental groups.

Dicaprio has been noted for his environmental activism before. The actor will be honored Sunday night for his work with the Leonardo DiCaprio Foundation, which focuses on the environment, at the Clinton Global Citizen Awards. He was also recently named a United Nations Messenger of Peace.