British artist, Mark Coreth sits on top of the “Sydney Ice Bear” carved from a 10 tonne block of ice to illustrate how humans affect climate change in the Arctic at Customs House on June 3, 2011 in Sydney, Australia. The public will be welcomed to touch the bear, and leave an imprint which will begin the melting process and act as a metaphor for how humans affect the environment. The ice bear's has visited six cities on it's global tour since 2009; the visit to Sydney coincides with World Environment Day on June 5. (Photo by Lisa Maree Williams/Getty Images)

A humpback whale is seen at the beginning of whale watching season during a Manly Whale Watching tour on June 8, 2011 in Sydney, Australia. The first day of winter in New South Wales, June 1st, marks the start of the Humback and southern right whales migration from southern regions to the north to warmer waters. Whale watchers should expect tohave plenty to see with the whale population increasing each year. The migration north continues through July and with the whales returning between September and November. (Photo by Cameron Spencer/Getty Images)

The Vietnam Slide Project was created by photo editor Kendra Rennick, who began collecting photo slides after a close friend lost her father, a Vietnam veteran. Her friend found a box of slides that her father had taken while in Vietnam and from there Rennick has continued to collect photographs that Vietnam veterans took during their tours of duty. Here: A photo taken from the collection of D.Thornton, who served in the First Air Cavalry division of the United States Army. (Photo by D.Thornton/The Vietnam Slide Project)

A man grimaces walking by the “Lettuce Ladies”, a group of PETA activists, during an event promoting a vegan lifestyle, downtown Bucharest, Romania, Monday, August 14, 2017. Two PETA vegan ambassadors distributed vegan food to passers by in the Romanian capital, the latest stop in a tour including the United States, Russia and Turkey aimed at promoting a vegan lifestyle. The sign reads in Romanian “start fresh: become vegan”. (Photo by Andreea Alexandru/AP Photo)

In this picture taken on Thursday, December 1, 2016, an Iranian woman covers herself with a blanket due to the cold, while visiting Khour salt lake during her tour of the Mesr desert about 305 miles (500 kilometers) southeast of the capital Tehran, Iran. Deserts make up parts of Iran which have recently become tourist destination for young Iranians looking for a break on their weekend. The increase in tourists to the desert has stimulated economic growth in the area. (Photo by Ebrahim Noroozi/AP Photo)

An Orangutan named “Pacquiao” and zoo owner Manny Tangco, wearing Santa costumes, embrace in front of Brown Philippine Deer while giving school children a tour ahead of the next week's Christmas celebration Thursday, December 18, 2014 in suburban Malabon city, north of Manila, Philippines. The yearly treat is aimed at encouraging residents to be sensitive to the feelings of animals especially when exploding firecrackers for the raucous celebration. (Photo by Bullit Marquez/AP Photo)

A makeshift cart with containers is seen at a suspected drug tunnel under construction during a media tour by Mexican Army in Tijuana April 7, 2015. Mexican soldiers foiled the construction of a suspected drug tunnel underneath a house near the U.S. border, arresting nine people and impounding a truck used to clear debris, the Army said on Tuesday. Wired with lights, the tunnel was being built next to the Tijuana border crossing, south of San Diego, California, and near a Mexican air force installation as well as a regional federal police facility. (Photo by Reuters/Stringer)

A woman in traditional clothes wears a pin showing North Korea's founder Kim Il-sung (L) and former leader Kim Jong-il, on her dress as she welcomes foreign reporters to a temple during a government organised tour just outside Pyongyang October 8, 2015. North Korea is getting ready to celebrate the 70th anniversary of the founding of its ruling Workers' Party of Korea on October 10. (Photo by Damir Sagolj/Reuters)