People walk along the Dune du Pilat (Dune of Pilat), the tallest sand dune in Europe, in La Teste de Buch, near Bordeaux, France, June 15, 2016. The dune has a volume of about 60,000,000 m³, measuring around 500 m wide from east to west and 2.7 km in length from north to south. Its height is currently 110 meters above sea level. (Photo by Sergio Perez/Reuters)

A Filipino girl is carried along a flooded road in suburban Mandaluyong, east of Manila, Philippines, as monsoon downpours intensify while Typhoon Nepartak exits the country on Friday, July 8, 2016. In the Philippine capital, Manila, and outlying provinces, classes in many schools were suspended and at least six flights, including one scheduled to come from Taiwan, were canceled because of stormy weather and floods following monsoon downpours intensified by the typhoon, Filipino officials said. (Photo by Aaron Favila/AP Photo)

As the sun rises, Gentoo penguins start their day on Wednesday, February 17, 2016, on Sea Lion Island, Falkland Islands. Sea Lion Island, which lies about 10 miles to the south of mainland East Falkland, is the southern most human-inhabited island of the more than 750 islands and islets of the Falkland Islands. (Photo by Jahi Chikwendiu/The Washington Post)

People on motor bikes celebrate American President Barack Obama's visit to Kenya by holding up a photo, center top, of the president and First Lady Michelle Obama in Kisumu, Kenya, Saturday, July 25, 2015. President Barack Obama heralded Africa as a continent “on the move” Saturday as he opened a U.S.-sponsored business summit in Kenya, the East African nation where he has deep family ties. (Photo by AP Photo)

A visiitor bungee jumps during an outdoor festival to celebrate German Unity Day on the 21st anniversary of German reunification on October 3, 2011 in Berlin, Germany. German Unity Day is a national holiday and marks the day West Germany and East Germany were reunited in 1990 following the collapse of the Iron Curtain. (Photo by Adam Berry/Getty Images)

An aerial view shows a sinkhole 3.5 km (2 miles) to the east of Solikamsk-2 mine in Perm region, November 20, 2014. Shares in Russia's Uralkali, the world's top potash producer, fell sharply for a second day on Wednesday after a mine accident that could reduce global supplies and push up prices of the crop nutrient worldwide. Uralkali shares have fallen 28 percent since Tuesday when it suspended work at its Solikamsk-2 mine, which accounts for a fifth of the company's output and 3.5 percent of global capacity, following an inflow of water. A sinkhole, stretching 30 by 40 metres (yards), found at an abandoned mine 3.5 km (2 miles) to the east, increased concern about the future of the mine because an inflow of water and the resulting sinkhole in 2006 forced another Uralkali operation to shut permanently. (Photo by Reuters/Press service of Uralkali company)

Women labourers work at the construction site of a road in Kolkata January 8, 2015. Across towns and cities in India, it is not uncommon to see women cleaning building sites, carrying bricks and or shoveling gravel – helping construct the infrastructure necessary for the country's economic and social development. They help build roads, railway tracks, airports, and offices. They lay pipes for clean water supplies, cables for telecommunications, and dig the drains for sewage systems. But although women make up at least 20 percent of India's 40 million construction workers, they are less recognized than male workers with lower pay and often prone to safety hazards and sexual harassment. They are often unaware of their rights or scared to complain, say activists now trying to campaign for better treatment of women in the construction industry. (Photo by Rupak De Chowdhuri/Reuters)

A Chinese man wears a mask to protect against pollution as he waits at a red light while commuting to work in heavy smog on December 8, 2015 in Beijing, China. The Beijing government issued a 'red alert' for the first time since new standards were introduced earlier this year as the city and many parts of northern China were shrouded in heavy pollution. Levels of PM 2.5, considered the most hazardous, crossed 400 units in Beijing, lower than last week, but still nearly 20 times the acceptable standard set by the World Health Organization. The governments of more than 190 countries are meeting in Paris to set targets on reducing carbon emissions in an attempt to forge a new global agreement on climate change. (Photo by Kevin Frayer/Getty Images)