New York City’s announcement Wednesday that it will divest billions of dollars from the fossil fuel industry and sue the oil companies accelerating climate change has energized environmental activists around the world — and celebrities are no exception.

One A-Lister — who Vanity Fair called “Hollywood’s No. 1 climate change warrior” — has championed the massive action, tweeting his support for the Big Apple’s decision to divest from Big Oil and throwing his starpower behind the renewable energy campaign.

NYC is the first big city in America to sue and divest from Big Oil. #stopfundingfossilspic.twitter.com/7aqjV3E46J

— Leonardo DiCaprio (@LeoDiCaprio) January 10, 2018

Take Action: Stand Up for the Arctic

For years, Academy Award winner Leonardo DiCaprio has promoted and financed efforts to stop climate change, protect coral reefs threatened by increasing temperatures, and prevent sea-level rise.

Though the recent spell of frigid weather throughout much of the US may have distracted some people from the reality of climate change, worldwide temperatures have actually increased significantly in the past few years.

In fact, rising temperatures shrink the Arctic ice fields by more than 7% every decade and 16 of the 17 hottest years ever recorded have occurred since 2000.

We must protect our oceans. Join @DiCaprioFdn and bring awareness to #oceanconservation. Click here to find out how: https://t.co/FoUtkaHBR3pic.twitter.com/VY6mFy29NB

— Leonardo DiCaprio (@LeoDiCaprio) June 20, 2017

Just like Leo, Global Citizen campaigns on ending the use of fossil fuels and embracing renewable energy sources in order to fight climate change. You can take action here.

Though DiCaprio rose to super-stardom with roles in Titanic and Romeo + Juliet before starring in acclaimed films like The Departed, he has shifted his focus to environmental causes. In his Twitter bio, he describes himself as an “Actor and Environmentalist.”

In 2016, DiCaprio produced Before the Flood, a documentary that reveals the drastic effects of climate change around the globe. He also plans to revive environmental action hero Captain Planet for a feature film.

Read More: Leo DiCaprio Is Making a Captain Planet Movie

In addition to filmmaking, DiCaprio frequently tweets his support for efforts to prevent climate change and even hosted a Titanic reunion to raise money for environmental causes.

Watch @EnvDefenseFund's new enviro-documentary series on the value of using technology to cut oil and gas pollution. https://t.co/nQoBJzI1tR

— Leonardo DiCaprio (@LeoDiCaprio) December 20, 2017

And DiCaprio seems excited to see his hometown embrace his mission by becoming the first big city to divest from fossil fuels.

Read More: Leo DiCaprio and Kate Winslet Just Low-Key Raised $30M for the Environment

"New York City is standing up for future generations by becoming the first major US city to divest our pension funds from fossil fuels,” New York City Mayor Bill de Blasio said in a statement Wednesday. “We’re bringing the fight against climate change straight to the fossil fuel companies that knew about its effects and intentionally misled the public to protect their profits.”