Leonardo DiCaprio, who spent the summer traveling around the world in his private jet, stopped in New York on Sunday for the “People’s Climate March,” where he demanded that global leaders finally address the climate crisis.

The actor and environmental activist was recently nominated by the United Nations to receive the prestigious “Messenger of Peace” award, with which he will be honored at the UN Climate Summit in New York on Sept. 23.

Honored to accept at this key moment for #Climate2014. RT @UN: Ban Ki-moon names @LeoDiCaprio Messenger of Peace http://t.co/GfOEvhlvAJ

— Leonardo DiCaprio (@LeoDiCaprio) September 16, 2014

DiCaprio was accompanied by former vice president Al Gore at the rally.

Gore, who won an Oscar for his global warming documentary “Inconvenient Truth,” was exposed in 2007 for hypocrisy. A report revealed that his Nashville mansion consumed more energy than 20 times the national average. 

In the film, the former vice president challenged Americans to live a more conservative lifestyle by reducing their energy consumption at home.

Proud to march with @ClimateReality at today’s #PeoplesClimate march. Let your voice be heard: http://t.co/cTdCaa6JnM

— Al Gore (@algore) September 21, 2014

This weekend, more than 300,000 people, including celebrities, students, scientists, and supporters marched and waved flags to the cadence “No more climate change.” Some protestors held signs that read “Give a s***” and “Let’s not wait for Will Smith to save us ok?” 

New York City Mayor Bill de Blasio came to show his support.

Joined the #PeoplesClimate march–because we only have one planet, and we need to take care of it. pic.twitter.com/SLtpNOEQmb

— Bill de Blasio (@BilldeBlasio) September 22, 2014

“Climate change is an existential threat to New Yorkers and our planet,” de Blasio said, according to the Daily Mail. “Acting now is nothing short of a moral imperative.” 

The event was organized by 350.org, founded by Bill McKibben, and more than 1,000 environment groups were in attendance. In addition, an estimated 2,000 “climate-focused” events were taking place in other countries including Afghanistan, Britain, France, and Bulgaria.

Remind any politician you see: this was the largest political gathering about anything in the US in a very very long time. About anything!

— Bill McKibben (@billmckibben) September 21, 2014

President Obama will join forces with 120 world leaders on Tuesday for the United Nations climate change summit, where DiCaprio will be rewarded for his advocacy efforts. 

Secretary General Ban ki-moon has high hopes that the massive gathering will encourage others to take action.

“There is no Plan B because we do not have a planet B,” he urged. “We have to work and galvanize our action.”