Artist Kong Ning wears a wedding dress made from respirators to highlight concerns about air quality and pollution in Beijing, China on December 1, 2015. (Photo by Luo Xiaoguang/Xinhua Press/Corbis)

Residents watch the ocean waves crash into the water front, after the passage of Hurricane Irma, in Cuba, Sunday, September 10, 2017. (Photo by Ramon Espinosa/AP Photo)

Filipino typhoon survivor children, who escaped after their village was attacked by allegedly armed men, wait for social workers in the super typhoon devastated city of Tacloban, Leyte province, Philippines, 13 November 2013. Aid workers and relief supplies were being poured into eastern provinces hit by Typhoon Haiyan, which aid agencies and officials estimated has left thousands dead and staggering destruction in its wake. The official death toll in the Philippines from one of the world’s strongest typhoons rose to 1,833, the national disaster relief agency said with many towns still unaccounted for. (Photo by Dennis M. Sabangan/EPA)

The British Breitling Wingwalkers, Danielle Hughes and Emily Guilding, soar above the Palm Jumeirah in Dubai at 1,500 feet (460 meters) in excess of 100mp/h, ahead of their Dubai debut performance at the 2014 UIM Skydive Dubai XCAT World Powerboating Series, on Saturday, 13th December 2014. The British team is the only aerobatic formation display team who employ full time wingwalkers and fly their two Breitling-liveried 1930's Boeing Stearman bi-planes at Air Shows and major sporting events around the world. (Photo by Katsuhiko Tokunaga/Breitling via AP Images)

A young woman cools herself in a fountain in Budapest, Hungary July 6, 2015. Over the weekend, a heat wave has reached Hungary with temperatures topping 38 degrees Celsius (100.4 degrees Fahrenheit). (Photo by Laszlo Balogh/Reuters)

Young men play basketball on an improvised court wedged between a construction site and the shells of once grand colonial homes in Havana, July 20, 2015. As much as the young in Cuba welcome political opening and economic reform, such changes are unlikely to filter down to their lives anytime soon. (Photo by Meridith Kohut/The New York Times)

A Citroen Aircross concept car is pictured during the media day at the Frankfurt Motor Show (IAA) in Frankfurt, Germany, September 15, 2015. The car show runs through September 27. (Photo by Kai Pfaffenbach/Reuters)

Gold bars from the vault of a bank and Swiss one franc coins are seen in this illustration picture taken in Zurich November 20, 2014. The “Save our Swiss gold” proposal, spearheaded by the right-wing Swiss People's Party (SVP), aims to ban the central bank from offloading its reserves and oblige it to hold at least 20 percent of its assets in gold. The referendum is scheduled for November 30. The SVP argues it would secure a stable Swiss franc. (Photo by Arnd Wiegmann/Reuters)