People wait on a taxi line near Madison Square Garden, Wednesday, September 23, 2015, as a 225-foot-tall hand-painted billboard of Pope Francis stands out at Eighth Avenue in New York. The billboard, designed by Israel Ochoa of DeSales Media, including a photo by photographer Giulio Napolitano, marks the arrival of the pope Thursday. (Photo by Craig Ruttle/AP Photo)

A witch doctor prepares an offering for the inauguration of the World People's Conference on Climate Change and the Defense of Life, prior to the World Climate Change Conference, in Tiquipaya, Bolivia, October 10, 2015. Almost 150 nations, including major emitters led by China and the United States, have submitted plans to the United Nations for curbing greenhouse gas emissions blamed by the U.N. for causing more floods, droughts and heat waves. France will host the conference in Le Bourget, near Paris, from November 30 to December 11, 2015. (Photo by David Mercado/Reuters)

Wang Zhengqing, a 74 year old pneumoconiosis patient, smokes his pipe at Yangjia Hospital in Wuyi County, Zhejiang Province, China October 19, 2015. Former miner Wang was diagnosed with the disease, which is caused by dust inhalation, when he was 24 and has lived at Yangjia Hospital for ten years. (Photo by Damir Sagolj/Reuters)

Children play on top of a cargo ship that was swept during the onslaught of Typhoon Haiyan in Tacloban city in central Philippines November 2, 2015, ahead of the second anniversary of a devastating typhoon that killed more than 6,000 people in central Philippines. The front part of the ship was retained in the area and made into a memorial and will be inaugurated on November 8 to commemorate the second anniversary of Typhoon Haiyan. (Photo by Erik De Castro/Reuters)

Black-headed gulls sit on pickets at a riverside in Tokyo, Japan, December 27, 2015. (Photo by Toru Hanai/Reuters)

A Palestinian boy herds sheep in front of the ruins of Yasser Arafat International Airport, which was bombed by Israel in the past, in Rafah in the southern Gaza Strip February 5, 2016. Nabil Shurafa's travel agency in Gaza was once packed with clients booking flights to London, Paris, New York or cities across the Arab world. These days, he's lucky if anyone comes in, as so few people can get out. (Photo by Ibraheem Abu Mustafa/Reuters)

A small section of the expanding remains of the Veil Nebula, a massive star that exploded about 8,000 years ago. The entire nebula is 110 light-years across, covering six full moons on the sky as seen from Earth, and resides about 2,100 light-years away in the constellation Cygnus, the Swan. (Photo by Reuters/NASA/ESA/Hubble)

Female Siberian tiger Dasha yawns in the new enclosure at the zoo in Duisburg, Germany, 30 March 2016. The new facility is three times larger than the old one and will be opened to the public on the same day. (Photo by Roland Weihrauch/EPA)