Time magazine announced its 2019 "Person of the Year" Wed.: 16-year-old Swedish climate activist Greta Thunberg.

Time: "She has offered a moral clarion call to those who are willing to act, and hurled shame on those who are not."

Thunberg is the youngest person ever to be awarded Time's "Person of the Year" award. Here she is with another awardee.

In 2018, Thunberg staged the first "skolstrejk för klimatet," or "School Strike for Climate," in Stockholm, Sweden.

Thunberg sat outside of the Swedish parliament every Friday to push Sweden to lower its carbon emissions.

People across the world followed her lead. In March, students from 125+ countries participated in a global climate strike.

In 2018, Time magazine named Thunberg one of Time's "25 most influential teens." She was also a Nobel Peace Prize nominee.

Thunberg has since become a global symbol of outrage over climate inaction, calling out world leaders.

In Aug., Thunberg sailed to New York on a zero-carbon yacht to attend the UN Climate Action Summit.

Thunberg delivered a powerful speech at the summit: "How dare you? You have stolen my dreams...with your empty words."

She also stood before Congress in Sept, submitting a UN report on climate change: "I don't want you to listen to me..."

It's been a big year for Great. Here are some of her best GIFs.