Swedish climate activist Greta Thunberg, 16, embarked on a trans-Atlantic sailing journey on August 14, 2019.  Accompanied by her father, the teenager will arrive in New York, emission-free, in two weeks, where she will speak at the UN Climate Action Summit on September 23.  After the United States, Thunberg will set sail for Canada, Mexico, and lastly Chile, where another UN climate summit will be held in December.