An alpaca is seen near the Inca citadel of Machu Picchu in Cusco December 2, 2014. Machu Picchu, a UNESCO World Heritage Site, is Peru's top tourist attraction, with the government limiting tourists to 2,500 per day due to safety reasons and concerns over the preservation of the ruins. (Photo by Enrique Castro-Mendivil/Reuters)

In this photo taken Tuesday, February 2, 2016, asylum seekers gather round a fire as they cook a meal overlooking the temporary Altnes camp refugee camp on the island of Seiland, northern Norway. Waiting for their asylum claims to be processed, hundreds of people in emergency shelters in Hammerfest and neighboring towns are slowly getting used to the extreme climate and unfamiliar customs of the High North. They say they have adapted to the cold – the temperature rarely drops below minus 10 degrees C (14 F) along the coast, though it gets much colder further inland. It’s the darkness that throws them off. (Photo by Alastair Grant/AP Photo)

A woman shoots her rifle at a forest shooting range near the village of Visnova, Czech Republic, June 9, 2016. (Photo by David W. Cerny/Reuters)

Tourist take pictures at Mai Khao Beach, as a plane approaches the Phuket International Airport in Phuket, Thailand March 17, 2016. With its palm-fringed beaches, Buddhist culture and racy nightlife, Thailand has been the poster child for Asian tourism for decades, attracting a range of visitors from backpackers and adventure-seekers, to families and culture vultures. But dark clouds could be forming even as a record of 32 million tourists are expected this year. (Photo by Athit Perawongmetha/Reuters)

Robot Xian'er is placed in the main building of Longquan Buddhist temple for photographs by the temple's staff, on the outskirts of Beijing, April 20, 2016. (Photo by Kim Kyung-Hoon/Reuters)

Guests arrive for the opening ceremony of the 23rd Life Ball in Vienna May 16, 2015. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. The Life Ball is a charity gala to raise money for people living with HIV and AIDS. (Photo by Leonhard Foeger/Reuters)

A woman with “I'm Charlie” written on her hand takes part in a Hundreds of thousands of French citizens solidarity march (Marche Republicaine) in the streets of Paris January 11, 2015. French citizens will be joined by dozens of foreign leaders, among them Arab and Muslim representatives, in a march on Sunday in an unprecedented tribute to this week's victims following the shootings by gunmen at the offices of the satirical weekly newspaper Charlie Hebdo, the killing of a police woman in Montrouge, and the hostage taking at a kosher supermarket at the Porte de Vincennes. (Photo by Yves Herman/Reuters)

This Thursday, January 22, 2015 photo made with a long exposure shows the glow from a Noctiluca scintillans algal bloom along the seashore in Hong Kong. The luminescence, also called Sea Sparkle, is triggered by farm pollution that can be devastating to marine life and local fisheries, according to University of Georgia oceanographer Samantha Joye. Noctiluca itself does not produce neurotoxins like other similar organisms do. But its role as both prey and predator tends can eventually magnify the accumulation of toxins in the food chain, according to R. Eugene Turner at Louisiana State University. (Photo by Kin Cheung/AP Photo)