Former President Barack Obama praised 16-year-old climate activist Greta Thunberg as “one of our planet’s greatest advocates” in a Tuesday afternoon Facebook post.

“At just 16 years old, Greta Thunberg is already one of our planet’s greatest advocates,” Obama wrote, praising her for her climate advocacy.

“Her age might have something to do with it. With full knowledge that her generation will bear the heaviest burden of climate change, she’s unafraid to believe that progress is possible—and fight for real change. She’s an example of why Michelle and I started the Obama Foundation — because we believe in a future that’s shaped by the courage and hope of young people like Greta.”

Greta— who started a global “Fridays for Future” school walkout movement to demand that adults to fight manmade climate change— stopped by the White House this week to participate in a protest where teenagers and young children held signs protesting everything from fossil fuels to the right to health care.

The 16-year-old climate alarmist from Sweden has also captured the hearts of many on the left, with celebrities such as Sarah Silverman fawning over her after she made a recent appearance on The Daily Show with Trevor Noah.

You think you will recognize Jesus when he comes back? I see him all around. He is this girl. And y’all don’t even see it. https://t.co/TAB5YafOQ0 — Sarah Silverman (@SarahKSilverman) September 14, 2019

“You think you will recognize Jesus when he comes back? I see him all around. He is this girl. And y’all don’t even see it,” Silverman tweeted on Saturday.