On Saturday, Billie Eilish and Woody Harrelson took to social media to share a video about the climate crisis, calling viewers around the world to action.

"Our earth is warming up and our oceans are rising", the pop star says in the clip, "extreme weather is wrecking millions of lives". Harrelson goes on to remind viewers of the California and Amazon forest fires before Eilish states that "up to one million species are becoming extinct because of mankind's actions."

But there is hope: "History shows us that when enough people rise up and demand change, those in power have no choice but to act", Woody Harrelson says, adding, "We must take back power. That means voting for leaders who care about the future of our planet."

While images and videos of our declining planet are shown, the actor and the singer mention the Friday's For Future climate strikes inspired by Greta Thunberg and refer to organisations like Greenpeace, emphasising how important it is to stay informed and make one's voice count.

The video was also shared by Greta Thunberg herself on Twitter.

#ClimateEmergency pic.twitter.com/eVCs2rk1q9

— billie eilish (@billieeilish) September 28, 2019

Both Woody Harrelson and Billie Eilish guest starred on Saturday Night Live last week, where the video was most likely shot. The singer performed two songs from her debut album, 'Bad Guy' and 'I Love You'.

Billie Eilish also sat down with Jimmy Fallon last week to talk about her Green World Tour. "We're trying to be as green as possible on the entire tour", she explains, "so there are no plastic straws allowed, the fans are going to bring their own water bottles, there are going to be recycle cans everywhere".

Watch the interview below:

Two weeks ago, 20,000-30,000 people attended the Dublin climate strike to demand action in averting the climate crisis. Get to know a few of the faces of the climate strike here.