Actor Candis Cayne performs at John Varvatos + OUT Support the Gay Men's Chorus of LA on September 29, 2016 in Los Angeles, California. (Photo by Matt Winkelmeyer/Getty Images for John Varvatos)

Two guards perform an execution in China, one holding the gun, the other holding a mask over the victim's face. (Photo by General Photographic Agency/Getty Images). Circa 1925

Ranger trainees and trainee dogs simulate an ambush against rhino poachers at the Paramount Group Anti-Poaching training and K9 (canine) academy on November 26, 2014 in Magaliesberg, South Africa. One of the largest of its kind in Africa, the Academy will address the ever increasing need for training of Conservation Officers in anti poaching activities, wildlife contraband detection, specialist K9 solutions and Ranger K9 handler training – all of which have proven success rates in combatting and apprehending poachers and their activities. (Photo by Gianluigi Guercia/AFP Photo)

Members of staff makes last minute touch ups of wax figure Chewbacca, from Star Wars, on display at “Star Wars At Madame Tussauds” on May 12, 2015 in London, England. (Photo by Stuart C. Wilson/Getty Images)

Dr. Anton Lim is interviewed by the media as he holds Kabang, a two-year-old injured mixed breed, upon arrival at the Ninoy Aquino International Airport in Pasay city, south of Manila, Philippines, early Saturday June 8, 2013 from San Francisco, Calif. Kabang lost her snout and upper jaw saving two girls' lives in the Philippines was headed back to its owner following treatment at the University of California, Davis veterinary hospital. (Photo by Bullit Marquez/AP Photo)

Two robotic legged squad support system (LS3) machines by the Defense Advanced Research Project Agency follow a technician during a demonstration at Joint Base Myer-Henderson Hall, Virginia, on September 10, 2012. (U.S. Marine Corps photo by Sgt. Mallory S. VanderSchans via The Atlantic)

Fire over Vieira de Leiria, Portugal, on October 16, 2017 as a series of deadly wildfires broke out across Spain and Portugal as the approach of Hurricane Ophelia whipped up strong winds that fanned the flames. (Photo by Helio Madeiras/News Pictures)

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)