Izzy Paskowitz helps Nixee Grace Chanowsky, 4, catch a wave Monday, August 18, 2014 at Wrightsville Beach, N.C. during the Annual Surfers Healing event for children with autism. Hundreds of people made their way to the beach to watch and cheer on the camp that was founded by Israel and Danielle Paskowitz. (Photo by Mike Spencer/AP Photo/The Star-News)

Cheng Liping, whose husband Ju was onboard Malaysia Airlines Flight MH370 which disappeared on March 8, 2014, shows a picture of she and her husband together and an old card with a message given by her husband, at a park near her house where she and her husband used to visit during an interview with Reuters in Beijing July 24, 2014. Cheng said her life has been totally changed since the incident. Their two little sons, who don't know about this incident, keep asking her when their dad is coming back. Six months after Malaysia Airlines Flight MH370, with 239 mostly Chinese people on board, disappeared about an hour into a routine journey from Kuala Lumpur to Beijing March 8, loved ones of missing passengers derive what comfort they can from what's left behind after the world's greatest aviation mystery. More than two dozen countries have been involved in the air, sea and underwater search for the Boeing 777 but months of sorties failed to turn up any trace – even after narrowing the search area to the southern Indian Ocean – long after batteries on the black box voice and data recorders had gone flat. (Photo by Kim Kyung-Hoon/Reuters)

This picture taken on September 3, 2014 shows a man taking pictures of floodwater released from the Three Gorges Dam, a gigantic hydropower project on the Yangtze river, in Yichang, central China's Hubei province, after heavy downpours in the upper reaches of the dam caused the highest flood peak of the year. Eleven people died and 27 others are missing after torrential rains battered southwest China's Chongqing, a municipality in the upper reaches of the Three Gorges Dam, causing thousands of houses to collapse, state media said. (Photo by AFP Photo/Stringer)

Cattle keepers from the Dinka tribe perform a traditional dance after a prayer session for peace and good health along the route to Rajaf Payam outside the capital Juba October 18, 2014. (Photo by Jok Solomon/Reuters)

People look at a loaded truck that got stuck in a sinkhole on a road in Guilin, Guangxi Zhuang Autonomous Region, January 7, 2015. No injury was reported, according to local media. (Photo by Reuters/Stringer)

A handout picture provided by Solar Impulse on 18 March 2015 shows the Swiss solar-powered plane Solar Impulse 2, HB-SIB, taking off with Swiss explorer Andre Borshberg on board for the third leg Ahmedabad to Varanasi, of the Round-The-World, in Ahmedabad, India, 18 March 2015. Swiss explorers Bertrand Piccard and Andre Borschberg attempt to circumnavigate the world flying with an aircraft, with a 72 metres wingspan, powered only by solar energy without a drop of fuel. (Photo by EPA/Solar Impulse)

Hundreds of Nigerians celebrate at an intersection in the flashpoint northern city of Kaduna on March 31, 2015 the victory of main opposition All Progressives Congress (APC) presidential candidate Mohammadu Buhari. (Photo by Nichole Sobecki/AFP Photo)

Growing cities, overuse of fertilizers and factory wastewater have degraded China's water supplies to the extent that half the nation's rivers and lakes are severely polluted. China aims to spend $850 billion to improve filthy water supplies over the next decade, but even such huge outlays may do little to reverse damage caused by decades of pollution and overuse in Beijing's push for rapid economic growth. Photo: Fishermen row a boat in the algae-filled Chaohu Lake in Hefei, Anhui province, June 19, 2009. (Photo by Jianan Yu/Reuters)