Swedish climate activist Greta Thunberg says young people must be prepared to keep striking to call for action on climate change — but she's encouraged by those joining the movement.
Thunberg spoke Friday in Denver, where she said she was overwhelmed by a crowd of several thousand people at a climate strike rally.
Echoing a line from a speech she delivered at the
United Nations last month, she asked several times of leaders, "How dare they?" Some in the Denver crowd repeated the line.