A Bukusu youth stands covered in mud in preparation for a circumcision ritual in Kenya's western region of Bungoma August 9, 2014. Circumcision rituals, which take place in August, are celebrated amongst some Kenyan tribes as an annual rite of passage into adulthood. (Photo by Noor Khamis/Reuters)

This picture taken on July 9, 2013 shows heavy flood waters sweeping through Beichuan in southwest China´s Sichuan province. Rainstorms sweeping across parts of China have affected millions, causing landslides and disabling transportation in provinces such as Sichuan and Yunnan, state media reported. (Photo by AFP Photo)

Among the fish populations that could be harmed by the Xayaburi dam in Laos is the critically endangered Mekong giant catfish, considered by the Guinness Book of World Records to be the world’s largest freshwater fish. The fish, which grows to 650 pounds and about 10 feet long, is only found in the Mekong River. It is migratory, moving between downstream habitats in Cambodia upstream to northern Thailand and Laos each year to spawn. Some experts fear the Xayaburi dam could block the migration and drive the giant catfish to extinction. (Photo by Courtesy of Zeb Hogan/University of Nevada, Reno)

Israeli soldiers pray at dawn as the conflict between Palestine and Gaza enters its seventh day on November 20, 2012 on Israel's border with the Gaza Strip. Hamas militants and Israel are continuing talks aimed at a ceasefire as the death toll in Gaza reaches more than 100 and also three Israelis killed by rockets fired by Palestinian militants. (Photo by Christopher Furlong)

Female panda Tian Tian makes her first appearance in front of the media since arriving from China on December 12, 2011 in Edinburgh, Scotland. (Photo by Jeff J. Mitchell/Getty Images)

Makers assemble the “Transformer X2” built by Chinese cartoon fans Sui Lulu, Zhang Yiming and Li Wei, was displayed at an exhibition center on October 8, 2007 in Nanjing of Jiangsu Province, China. (Photo by China Photos/Getty Images)

A general view of the Burj Khalifa on February 23, 2012 in Dubai, United Arab Emirates. At 829.84 m (2723 ft) tall the Burj Khalifa is currently the tallest building in the world. (Photo by Chris Jackson/Getty Images)

A picture made available on 17 July 2015 shows the bright line of the Milky Way above the old oaks at the Rogalin landscape Park in Rogalin village, near Poznan, on the night of 16 July 2015. (Photo by Lukasz Ogrodowczyk/EPA)