A round circle of smoke coming from the mouth of the Etna volcano is seen in the sky during an eruption on the southern Italian island of Sicily April 11, 2013. Mount Etna is Europe's tallest and most active volcano. (Photo by Antonio Parrinello/Reuters)

Turks stand in a silent protest in Kugulu Park in Ankara, Turkey, Wednesday, June 19, 2013. After weeks of sometimes-violent confrontation with police, Turkish protesters have found a new form of resistance: standing still and silent. The banner with an image of Turkey's founder Kemal Ataturk reads: “Which crazy person thinks they can put me in chains”. (Photo by Burhan Ozbilic/AP Photoi)

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)

Choristers from a Norwegian choir on a visit to New York take photographs in Times Square. (Photo by Vecchio/Three Lions/Getty Images). Circa 1956

Shy'm poses as she arrives at NRJ Music Awards 2012 at Palais des Festivals on January 28, 2012 in Cannes, France. (Photo by Pascal Le Segretain/Getty Images)

The sea otter mother with her three day old newborn pup ontop of her to keep it dry and warm while it sleeps. This devoted mother otter kept her newborn pup dry as she let the baby ride on her belly. Nature photographer Suzi Eszterhas, 40, spotted the adorable pair of southern sea otters swimming in Monterey Bay, California. The mother lifted the pup out of the water and on to her belly to keep it warm and dry and also blew air into the pup's fur to groom it. Ms Eszterhas was shocked to see the otters come closer to where she was standing and the mother left her child to float alone in the water. (Photo by Suzi Eszterhas/Minden Pictures/Solent News & Photo Agency)

Model Lily Donaldson flashes the peace sign as she leaves Victoria's Secret Fashion Show China casting in New York City on August 22, 2017. (Photo by Christopher Peterson/Splash News and Pictures)

An Indonesian vendor fixes a headscarf on a mannequin at a market in Jakarta in this December 21, 2006 file photo. (Photo by Reuters/Beawiharta)