Stockholm, Sweden - Greta Thunberg changed her Twitter bio to "bunny hugger" in a jibe at UK Prime Minister Boris Johnson's comments at a global climate summit.

Johnson, in typical colorful language, told the other world leaders on the videoconference that actions towards combatting climate change are not about "bunny hugging" but rather about "growth and jobs."

Thunberg earlier on Thursday was highly critical of the pledges made by leaders at the US-hosted summit, telling her Twitter followers in a video: "The gap between what we are doing, and what needs to be done, is widening by the minute ... Let’s call out their bullshit."

This is not the first time the 18-year-old Swedish climate activist has used her Twitter platform to go after at powerful politicians.

Thunberg sent a parting tweet to Donald Trump as he left the White House for the last time as president of the United States.

"He seems like a very happy old man looking forward to a bright and wonderful future. So nice to see!" she tweeted, posting a photo of Trump boarding the Marine One helicopter from the lawn outside the White House.

Thunberg's tweet paraphrased a tweet Trump made in 2019 after she had given an emotional speech at a UN summit on climate change.

"She seems like a very happy young girl looking forward to a bright and wonderful future. So nice to see!" Trump wrote at the time.

Russian President Vladimir Putin also went after Thunberg's UN speech, describing her as a "kind and sincere girl" who was misinformed about the world.

She then changed her Twitter bio to: "A kind but poorly informed teenager."