Miss USA Alyssa Campanella arrives at the 2nd Annual American Giving Awards at the Pasadena Civic Auditorium on December 7, 2012 in Pasadena, California. (Photo by Gregg DeGuire/WireImage)

A youth in make-up waits for the start of the annual Zombie walk in Mexico City, Saturday, October 22, 2016. Hundreds dressed in rags and ghoulish makeup to look bloody and decaying, gathered in the historic center of Mexico's capital. (Photo by Christian Palma/AP Photo)

A woman prays at the edge of a river during a protest against the building of a pipeline near the Standing Rock Indian Reservation near Cannonball, North Dakota, U.S. November 2, 2016. (Photo by Stephanie Keith/Reuters)

A citizen rides in smog on December 20, 2016 in Jinan, Shandong Province of China. Air quality index (AQI) readings exceeded 400 and some schools have suspended classes in Jinan. (Photo by VCG/VCG via Getty Images)

Firefighters work to quell a fire on an alleged clandestine gasoline storage in the Ixtlahuaca community, Mexico on January 5, 2016. Looting broke out at dozens of stores in Mexico on Wednesday on the sidelines of protests against a steep gasoline price increase as authorities detained more than 200 people. (Photo by Mario Vazquez de la Torre/AFP Photo)

Members of the University of Maryland women's lacrosse team react to something Trump said after posing for photographs during an event with NCAA championship teams at the White House on November 17, 2017. (Photo by Jabin Botsford/The Washington Post)

Girls dressed in Soviet WWII uniforms of traffic control officers as Russian President Vladiimir Putin lays a wreath in the Hall of Military Glory of the Mamayev Kurgan memorial complex commemorating the Battle of Stalingrad to mark the 75th anniversary of the victory in the battle in Volgograd, Russia on February 2, 2018. The battle between Nazi troops and the Soviet Army was a major pivotal moment in the Great Patriotic War and World War II. (Photo by Mikhail Metzel/TASS via Getty Images)

The photography of Art Wolfe covers the globe, capturing landscapes, wildlife, and cultures from every continent; here he talks through a selection of his favourite images. Art Wolfe is an American photographer and conservationist. His photographs have been noted by environmental advocacy groups for their “stunning” visual impact. Here: Snowy owlets (Bubo scandiacus), Arctic National Wildlife Refuge, Alaska, USA. (Photo by Art Wolfe/Art Wolfe Stock)