Participants costumed as zombies try to catch hobby runners during the so-called Zombie-Run at the harness racing track Karlshorst in Berlin, Germany, 18 May 2014. The runners carry small flags in their belts which they have to get safely across the finishing line while the zombies try to steal them. The sporting event is based on the US television series “The Walking Dead”. (Photo by Soeren Stache/DPA)

A model has makeup applied backstage prior to Lebanese designer Zuhair Murad fashion show held during the Haute Couture Fall/Winter 2014-2015 fashion collections in Paris July 10, 2014. (Photo by Philippe Wojazer/Reuters)

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)

Medical residents, who removed their clothes to protest against working conditions, take part on a protest during a strike in Barcelona, Spain, Tuesday, October 20, 2020. Regional authorities across Spain continue to tighten restrictions against a sharp resurgence of coronavirus infections that is bringing the country’s cumulative caseload close to one million infections, the highest tally in western Europe. (Photo by Emilio Morenatti/AP Photo)

A body of a victim lies trapped in the debris after an earthquake hit, in Kathmandu, Nepal April 25, 2015. Rescue efforts in Nepal are intensifying after nearly 2,000 people were killed on Saturday in the worst earthquake there in more than 80 years. Many countries and charities have offered aid to deal with the disaster. Seventeen people have been killed on Mount Everest by avalanches – the mountain's worst-ever disaster. Meanwhile a powerful aftershock was felt on Sunday in Nepal, India and Bangladesh, and more avalanches were reported near Everest. (Photo by Navesh Chitrakar/Reuters)

A handout photograph provided by Brian Kubicki of Costa Rican Amphibian Research Center on 26 April 2016 shows a “Crystal frog”, Hyalinobatrachium dianae (H. diane). This frog was discovered by US biologist Brian Kubicki and Costa Ricans Stanley Salazar and Robert Puschendorf in a rainy forest of Costa Rican caribbean after 40 years without notice of any new example of this kind. (Photo by Brian Kubicki/EPA/Costa Rican Amphibian Research Center)

Ukrainian President Petro Poroshenko gestures during a news conference in Kiev, Ukraine, June 5, 2015. REUTERS/Mykhailo Markiv/Ukrainian Presidential Press Service/Pool

Iggy Azalea shares a joke with Andy Lee and Hamish Blake during Bonds 100th birthday celebration event at Cafe Sydney on August 19, 2015 in Sydney, Australia. (Photo by Brendon Thorne/Getty Images)