In a Twitter post the former first lady told Greta to never "let anyone dim [her] light".
Michelle Obama's tweet comes after the incumbent U.S. president, Donald Trump, mocked Greta a day earlier on the social media platform. He insinuated that the activist has mental health problems and said she needs to "chill".
The mocking was spurred on by Greta's recent naming by TIME Magazine as 2019 Person of the Year.
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This was the year the climate crisis went from behind the curtain to center stage, from ambient political noise to squarely on the world's agenda, and no one did more to make that happen than @gretathunberg. Meaningful change rarely happens without the galvanizing force of influential individuals, writes editor-in-chief Edward Felsenthal, and in 2019, the earth's existential crisis found one in Thunberg. For that reason, she is TIME's 2019 Person of the Year. Read more about the #TIMEPOY choice at the link in bio. Photograph by @evgenia_arbugaeva for TIME; Video by @maxim_arbugaev for TIME
This is not the first time the president of the U.S. has made fun of the 16-year-old activist. In September he sarcastically called her a "happy young girl" after she delivered an emotional speech in front of the United Nations general assembly.
In both instances Greta Thunberg has responded to Donald Trump's comments by mockingly making them her Twitter bio.
Compiled by Phelokazi Mbude
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