Leonardo DiCaprio addressed world leaders on climate change at the United Nations “High-Level Signature Ceremony for the Paris Agreement” on Friday, the day before Earth Day.

“I have traveled all over the world for the past two years documenting how this crisis is changing the natural balance of our planet,” said DiCaprio. “I have seen cities like Beijing chocked by industrial pollution, ancient boreal forests in Canada that have been clear cut and rain forests in Indonesia that have been incinerated.”

Approved in Paris last December, the Paris agreement aims to slow the rise of greenhouse gasses that contribute to global warming.

“Our planet cannot be saved unless we leave fossil fuels in the ground where they belong,” said DiCaprio to the sound of applause. “A massive change is required right now that leads to a new collective consciousness, a new collective evolution of the human race inspired and enabled by a sense of urgency from all of you.”

The Oscar winner admitted to the room of leaders “all that I have seen on my journey has absolutely terrified me.” While he acknowledged the progress the UN has made by achieving the agreement, DiCaprio said “that will not be enough.”

“After 21 years of debates and conferences, it is time to declare no more talk, no more excuses, no more 10-year studies, no more allowing the fossil fuel companies to manipulate and dictate the science and policies that effect our future,” the Oscar-winning actor said. “This is the body that can do what is needed. All of you sitting in this very hall. The world is now watching. You will either be lauded by future generations or vilified by them.”

More than 175 countries gathered to sign the agreement at the United Nations headquarters in New York. The gathering set the record for the number of countries signing an agreement on the first available day, according to the Associated Press.