Greta Thunberg celebrates her 18th birthday with a snarky tweet No Comments Uncategorized Greta Thunberg turned 18 on Sunday, and she thanked her fans with a snarky Twitter message about how she was celebrating. Greta Thunberg turned 18 on Sunday, and she thanked her fans with a snarky Twitter message about how she was celebrating. Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to print (Opens in new window)Click to share on LinkedIn (Opens in new window)Click to share on Tumblr (Opens in new window)Click to share on Reddit (Opens in new window)Click to share on Pinterest (Opens in new window)Click to share on WhatsApp (Opens in new window)