The truant brat is actually being programmed by her father. He is using her to promote his own agenda.
She crossed the Atlantic in a luxury yacht. I doubt that they all leaned over the side to poop in the ocean. I read that there was a generator on board.
https://www.lonelyplanet.com/articles/greta-thunberg-nyc-eco-friendly-yacht
Thunberg will be joined by her father on the nonstop transatlantic journey, along with Swedish documentary maker Nathan Grossman, captain Boris Herrmann and founder of Team Malizia, Pierre Casiraghi (grandson of Monacos late Prince Rainier III and actress Grace Kelly).