Shailene Woodley Steps Out for Leonardo DiCaprio's 'Before the Flood' Premiere

Shailene Woodley flashes a smile while attending the National Geographic Channel Before the Flood screening at the United Nations Headquarters on Thursday (October 20) in New York City.

The 24-year-old Snowden actress was there to support the climate change documentary starring and executive produced by Leonardo Dicaprio.

PHOTOS: Check out the latest pics of Shailene Woodley

Shailene recently penned a moving essay about getting arrested for misdemeanor criminal trespass and misdemeanor engaging in a riot – and then pleading not guilty – after protesting the Dakota Access Pipeline along with others earlier this month.

Before the Flood will be released worldwide on October 30.