A Lebanese man wears a mask to protect himself from the dust as a sandstorm blows over the northern Lebanese city of Tripoli on September 8, 2015. An unseasonal sandstorm has hit the Middle East, reducing visibility and sending dozens to hospitals with breathing difficulties. (Photo by Ibrahim Chalhoub/AFP Photo)

A horse pulls a driving school car as other drivers push their vehicles behind during a demonstration by driving instructors in Belgrade, September 25, 1992. Due to gasoline shortage in the Yugoslav capital, driving instructors are staying away from work. (Photo by AP Photo)

The aurora borealis, or the northern lights occur over Derwentwater, near Keswick, England, Thursday October 8, 2015. The northern lights are the result of collisions between gaseous particles in the Earth's atmosphere with charged particles released from the sun. (Photo by Owen Humphreys/PA Wire via AP Photo)

A participant in wingsuit flies above Tianmen Mountain at Zhangjiajie Scenic Spot during the 4th Red Bull WWL China Grand Prix on October 16, 2015 in Zhangjiajie, Hunan Province of China. The 4th Red Bull WWL China Grand Prix will last three days from October 16-18 in Zhangjiajie. (Photo by ChinaFotoPress/Getty Images)

Labourers work at a garment factory in Bac Giang province, near Hanoi October 21, 2015. Vietnam's textiles and footwear would gain strongly from the TPP, after exports of $31 billion last year for brands such as Nike, Adidas, H&M, Gap, Zara, Armani and Lacoste. (Photo by Reuters/Kham)

A protester sprays paint on the window of a bank during a rally against Expo 2015 in Milan, Italy, April 30, 2015. The Milan Expo will open in the city on May 1. Officials are counting on some 20 million visitors to the six month-long exhibition of products and technologies from around the world. (Photo by Stefano Rellandini/Reuters)

A resident walks on a makeshift walkway above a flooded street from the rising Rio Solimoes, one of the two main branches of the Amazon River, in Careiro da Varzea of Amazonas State, Brazil, June 30, 2015. According to the state Civil Defense, more than 460,000 people were affected by strong rains in the state. (Photo by Bruno Kelly/Reuters)

A National Bolivarian Police officer rescues a man who was being attacked by protesters, who then threw rocks at them, during a protest demanding food a few blocks from Miraflores presidential palace in Caracas, Venezuela, Thursday, June 2, 2016. Venezuela is seeing rising frustration with widespread food shortages and triple-digit inflation. (Photo by Fernando Llano/AP Photo)