Pontoons, which were previously used as a floating jetty, are seen on the cracked ground of the Atibainha dam, part of the Cantareira reservoir, during a drought in Nazare Paulista, Sao Paulo state February 12, 2015. Brazil's worst drought in 80 years has left the Cantareira system, that provides greater Sao Paulo with most of its water, with the lowest water level on record. Brazil's economy is already expected to post zero growth this year. Worse yet, since Brazil depends on hydroelectric dams for about three quarters of its electricity, power shortages are also possible due to the drought, federal officials have said. (Photo by Paulo Whitaker/Reuters)

A native Brazilian competes in a tora competition, which is a race while carrying a log, during the Indigenous Youth Games of Pataxos nation in Santa Cruz de Cabralia, Bahia state, Brazil, April 18, 2016. (Photo by Roosevelt Cassio/Reuters)

Students of the "Escola de Papai Noel do Brasil" (Brazil's school of Santa Claus) travel on a ferry through Guanabara bay, during their graduation ceremony in Rio de Janeiro, Brazil, November 10, 2015. The school holds 4 days' lessons in Santa-training, teaching Christmas carols, how to interact with children, and also how to wear the heavy red suit in Rio's typical 104-degree (40 degrees celsius) summer weather that is common around the holidays. (Photo by Pilar Olivares/Reuters)

Tech. Sgt. Milo Hinson, 3rd Combat Camera Squadron, uses a flashlight while shooting a Berretta 9mm during the night-fire portion of Advance Weapons, Tactics and Techniques training in San Antonio. During night-fire training, airmen learn how to tactically illuminate targets with flashlights and practice using night vision goggles. (Photo by Staff Sgt. Jonathan Snyder/U.S. Air Force). 2011

Caroline Wozniacki of Denmark serves to Alisa Kleybanova of Russia during the BNP Paribas Open at the Indian Wells Tennis Garden on March 15, 2011 in Indian Wells, California. (Photo by Matthew Stockman/Getty Images)

Ali Carter of England looks on during the match against Stuart Bingham of England during the 2011 China Open at Beijing University Students Gymnasium on March 30, 2011 in Beijing, China.

A model showcases designs on the catwalk during Beijing Institute of Fashion Technology and Taiwan Shin Chien University Graduates Collection show of China Fashion Week A/W 2011 on March 25, 2011 in Beijing, China. (Photo by Feng Li/Getty Images)