Greta Thunberg, the activist who has quickly become a leading voice on climate change, is Time’s Person of the Year for 2019. At 16, she is the youngest person to earn the title in the magazine’s 92-year history.

Thunberg burst onto the world stage in the past year, organizing school strikes and protest marches to call attention to a climate crisis that she says older generations are not taking seriously enough.

She has famously called out world leaders for debating scientific facts and failing to stop a global warming trend that will affect the world’s children more than it affects anyone who’s currently in power.

Reacting to the honor, Thunberg said she is “a bit surprised” to be chosen, according to The Associated Press, which adds that Thunberg dedicated her recognition to other young activists.

Thunberg is currently in Madrid, where she delivered a speech at a U.N. climate conference on Wednesday morning.

“Well, I am telling you there is hope. I have seen it,” she told the audience. “But it does not come from the governments or corporations. It comes from the people.”

Thunberg has drawn the support of millions of people, including demonstrators who coordinated an international protest day in September when she was visiting Washington and other U.S. cities.

The Swedish teenager has spoken with the pope, the U.N.

 secretary-general and other influential figures. But Thunberg has also been mocked or criticized by climate skeptics — and by powerful leaders such as President Trump, Brazil’s President Jair Bolsonaro and Russia’s President Vladimir Putin. She has shrugged off those attacks, saying she won’t be silenced.