A wolf looks into the camera at the 30 km (19 miles) exclusion zone around the Chernobyl nuclear reactor in the abandoned village of Orevichi, Belarus, March 2, 2016. What happens to the environment when humans disappear? Thirty years after the Chernobyl nuclear disaster, booming populations of wolf, elk and other wildlife in the vast contaminated zone in Belarus and Ukraine provide a clue. (Photo by Vasily Fedosenko/Reuters)

Labourers walk near trucks loaded with logs, which are trapped on a muddy road, near an unreserved forest in the village of Igbatoro, southwest Nigeria, August 28, 2014. Wood, a form of biomass, is the sole source of energy for hundreds of millions of Africans who lack access to modern sources of power, and logging, both legal and illegal, remains a lucrative business that has contributed to the rapid shrinking of Africa's rainforests and woodlands. (Photo by Akintunde Akinleye/Reuters)

Models of the “Altyr” fashion theatre, dressed in Khakas national costumes, get over a wooden fence during a photo session, as a part of the rehearsal for the Tun-Pairam traditional holiday (The Holiday of the First Milk) celebration at a museum preserve outside Kazanovka village near Abakan in the Republic of Khakassia, Russia, May 28, 2016. (Photo by Ilya Naymushin/Reuters)

A village girl, donning capes mostly of dried banana leaves and covered in mud, attends a mass in a bizarre annual ritual to venerate their patron saint, John the Baptist, Friday, June 24, 2016 at Bibiclat, Aliaga township, Nueva Ecija province in northern Philippines. (Photo by Bullit Marquez/AP Photo)

Pakistani passengers ride on crowded train returning from their hometown and villages after celebrating the Eid al-Fitr holiday to mark the end of the Muslim holy fasting month of Ramadan, to Lahore, Pakistan, Monday, July 11, 2016. (Photo by K.M.Chaudary/AP Photo)

32 year old Mahada Khatum repairs a fishing net outside her home in the Shamalapur Rohingya refugee settlement on April 11, 2014 in Chittagong district, Bangladesh. Some years ago she escaped violence and discrimination from the Zomgara Baharchara village in the Meherulla district of Myanmar. (Photo by Getty Images/Stringer)

A combination photograph shows revelers dressed in "Dia de Muertos" or "Day of the Dead" themes as they pose for photos while taking part in the Greenwich Village Halloween Parade in the Manhattan borough of New York October 31, 2015. (Photo by Carlo Allegri/Reuters)

Tourists pose for a selfie in Cancun, October 13, 2015. Cancun's transformation in the 1970s from a small Caribbean fishing village into a strip of nightclubs and high-rise hotels has reduced biodiversity and polluted water resources as infrastructure struggles to keep up. (Photo by Edgard Garrido/Reuters)