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)

An arctic tern feeds its chick on the Farne Islands off the Northumberland coast, northern England July 8, 2013. The Farne Islands, which lie off the coast of northeast England, are home to a huge array of wildlife. The islands are owned and protected by the British conservation charity, the National Trust, which says they host some 23 species of seabird, as well as a substantial colony of grey seals, who come to have their pups there in the autumn. Every five years the National Trust carries out a census of the islands' population of puffins, and this year's survey showed there were almost 40,000 nesting pairs on the islands – an 8 percent rise from 2008. (Photo by Nigel Roddis/Reuters)

Documenting the effects of climate change first hand over the past eight years, Camille Seaman fears we may be on the road to the last iceberg. Photographing the enormous frozen floats at both poles for the past eight years, the Californian adventurer has seen the receding ice shelves and experienced the changing warmer weather. Feeling that her intimate and emotional work documents a snapshot of history, Camille presents her series “The Last Iceberg” as a study of what she sees as the personality of each huge iceberg. Drawing parallels with the famous novel, “The Last of the Mohicans”, Camille, 42, wonders whether these unique, almost alien natural features will become a thing of the past or part of nature's renewal process. (Photo by Camille Seaman/Barcroft Media)

An image produced by the Hubble telescope of the perfectly “edge-on” galaxy, or NGC 4013, March 1, 2001. This new Hubble picture reveals, with great detail, huge clouds of dust and gas extending along, as well as far above, the galaxy's main disk. NGC 4013 is a spiral galaxy, similar to the Milky Way, lying some 55 million light-years from Earth in the direction of the constellation Ursa Major. Viewed face-on, it would look like a nearly circular pinwheel, but NGC 4013 happens to be seen edge-on from our vantage point. Even at 55 million light-years, the galaxy is larger than Hubble's field of view, and the image shows only a little more than half of the object, albeit with unprecedented detail. (Photo Courtesy of NASA/Newsmakers)

Floating on clear deep water and reflections near the cave entrance. Visitors can either bring their own kayaks or rent boats from the local community to paddle deep inside the cave and marvel at its wonders on March 2015 at Tham Khoun Ex, Laos. Tham Khoun Xe, commonly known as the Xe Bang Fai River Cave, in Laos, has over 15km of passages filled with awe-inspiring views and wide expanses of water. Photographer, John Spies, 59, captured scenes from the entrances of the huge underground river passages, intricate cave formations and views from a passage high above the water. The cave is formed by the Xe Bang Fai river, a major tributary of the Mekong and in the dry season can be traversed using inflatable kayaks. (Photo by John Spies/Barcroft Media/ABACAPress)

Second Place Winner: “Thunderstorm at False Kiva”. I hiked out to these ruins at night hoping to photograph them with the Milky Way, but instead a thunderstorm rolled through, creating this dramatic image. – Max Seigal. National Geographic Traveler Director of Photography Dan Westergren, one of this year's judges, shares his thoughts on the second place winner: “This photo combines two different scenes into one: the small kiva in a cliff dwelling and the grand vista of Canyonlands National Park across the valley. I really like the two different color palettes – warm inside and purple outside. This two-for-one scene was caused by the lightning storm outside the dwelling, which lit up the landscape like it was a huge electronic flash. Looking at this picture I can imagine what a wonderful sight it must have been for the ancient people who lived here. It doesn't seem too amazing now in our modern world, but might have been mind-blowing for the prehistoric residents”. Location: Utah. (Photo and caption by Max Seigal/National Geographic Traveler Photo Contest)

The Rio de Janeiro Olympics kick off on August 5 for some two weeks of competitive games drawing athletes as well as audiences from around the world. As they prepare to cover the event, Reuters photographers look back on their favourite pictures from past Olympics where they captured the action on the ground as well as the participants' tears and joy that followed. (Photo by Lucy Nicholson/Reuters)

“The knight and his steed”. This picture was taken in a natural but controlled environment. There are pictures that can not be done in nature or that would imply a very high cost of both time and money, thats why photography workshops are run conducted at strategic locations and bringing EVERYONE who is interested, the basic notions (lighting, camera handling, composition, etc...) or the specimens, and afford them the opportunity to take pictures like this. Although controlled, this shot was not prepared at all, I was performing a workshop with the agalychnis callidryas treefrog from Costa Rica when the frog managed to jump to the branch where this huge titan was sleeping... I had my gear ready so I only had to change a few settings and shoot... the rest is history. (Photo and caption by Nicolas Reusens Boden (Sweden)/2014 Sony World Photography Awards)