(CBS NEWS)- President Trump mocked teen climate change activist Greta Thunberg on Twitter Thursday, one day after she was named Time’s 2019 Person of the Year. Thunberg did not waste any time in responding.

Mr. Trump called Time’s recognition of the 16-year-old “so ridiculous.”

“Greta must work on her Anger Management problem, then go to a good old fashioned movie with a friend! Chill Greta, Chill!” he tweeted.

Thunberg responded by changing her bio on Twitter: “A teenager working on her anger management problem. Currently chilling and watching a good old fashioned movie with a friend.”

Social media users also came to her defense after Mr. Trump’s tweet. Actor George Takei said, “sore losers gonna be sore.” Senator Bob Casey, a Democrat from Pennsylvania, criticized Mr. Trump for his “decision to mock a child – AGAIN,” saying it is “beneath the office of the President and an insult to people throughout the world.”

This isn’t the first time Mr. Trump has attacked Thunberg online. In September, Thunberg scolded world leaders at the United Nations for failing to address climate change. Mr. Trump tweeted a video clip of her remarks with what appeared to be a sarcastic comment: “She seems like a very happy young girl looking forward to a bright and wonderful future. So nice to see!”

She responded by changing her Twitter bio to say she is a “very happy young girl looking forward to a bright and wonderful future.”

Thunberg first made headlines last year with her solitary strike against climate change outside Sweden’s parliament. Since then, she’s inspired millions of supporters to rally in more than 150 countries and was nominated for a Nobel Peace Prize.

On Wednesday, Time said Thunberg won its Person of the Year award “for sounding the alarm about humanity’s predatory relationship with the only home we have, for bringing to a fragmented world a voice that transcends backgrounds and borders, for showing us all what it might look like when a new generation leads.”

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