This is not Greta Thunberg firing a rifle
NO: The person shooting a rifle in this video is not 16-year-old climate activist Greta Thunberg. YES: She is Emmy Slinge, a 31-year-old engineer in Sweden (the page is in Swedish.)
NOTE: If you use Google’s Chrome browser, Google will offer to translate pages written in languages other than English You can also use translate.google.com.
ALSO NOTE: The claim that the video showed Thunberg shooting the rifle was an especially popular meme in Brazil, and Comprova, a fact-checking initiative supported by four news organizations there, was the first to debunk it (the page is in Portuguese). A reporter from Estadão, one of the news outlets involved with Comprova, contacted Slinge to confirm that she was the person in the video.
Resource: Comprova used the InVid fake news debunker browser extension to find the source video.