Indian boy Hassan Malik works in a leather shoe factory at Topsia in Calcutta, eastern India, 19 November 2013. The leather industry occupies an important place in the Indian economy. It is an employment intensive sector with a vast potential for growth and exports but also a pollution intensive industry that relies on cheap labor. One of the major production centers for leather and leather products is located in Calcutta, West Bengal. Hundreds of tanneries are operated in the city’s Tiljala, Topsia and Tangra districts. They are mostly run by local families living and working under poor conditions. (Photo by Piyal Adhikary/EPA)

in Qayyarah, about 31 miles (50 km) south of Mosul, Iraq, Sunday, October 23, 2016.in Qayyarah, some 50 kilometers south of Mosul, Iraq, Sunday, Oct. 23, 2016. Islamic State fighters torched a sulfur plant south of Mosul, sending a cloud of toxic fumes into the air that mingled with oil wells the militants had lit on fire to create a smoke screen. (Photo by Marko Drobnjakovic/AP Photo)

People dodge waves in Sansha Township of Xiapu, southeast China's Fujian Province, July 10, 2015. China is on highest alert as super typhoon Chan-Hom approaches the eastern coast at high speeds. The National Meteorological Center issued a red alert on Friday morning for Chan-Hom, whose center was spotted 550 km southeast off the coast of Zhejiang Province at 5 a.m. (Photo by Jiang Kehong/Xinhua)

A sledding dog is covered in ice after spending the night in the open air with his musher at the polar base of Val-Cenis, as they ready for the next stage of the 12th edition of “La Grande Odyssee” sledding race across the Alps on January 17, 2016 in Val Cenis Lanslevillard. (Photo by Jean-Philippe Ksiazek/AFP Photo)

Artists perform during the opening show directed by German director Volker Hesse, on the opening day of the Gotthard rail tunnel, at the fairground Rynaecht at the northern portal in Erstfeld, Switzerland, Wednesday, June 1, 2016. The construction of the 57 kilometer long tunnel began in 1999, the breakthrough was in 2010. After the official opening on June 1, the commercial operation will start in December 2016. (Photo by Ruben Sprich\Pool Photo via AP Photo)

A couple sunbath on the beach in Ostrowo, northern Poland, July 20, 2015. Picture taken July 20, 2015. (Photo by Kacper Pempel/Reuters)

Lightning strikes during a storm over the promenade of Palma de Mallorca, Balearics, Spain, on November 4, 2017. Mallorca and Menorca were in yellow alert because of heavy rain and violent winds. (Photo by Cati Cladera/EPA/EFE)

Smoke rises from a replica of a T-Rex after it burst into flames at the Royal Gorge Dinosaur Experience in Canon City, Colorado, U.S. in this picture obtained from social media March 22, 2018. (Photo by Reuters/Royal Gorge Dinosaur Experience)