In this Thursday, May 8, 2014 photo, Iranian coal miners push metal carts to be loaded with coal at a mine near the city of Zirab 212 kilometers (132 miles) northeast of the capital Tehran, on a mountain in Mazandaran province, Iran. International sanctions linked to the decade-long dispute over Iran's nuclear program have hindered the import of heavy machinery and modern technology in all sectors, and coal mining is no exception. (Photo by Ebrahim Noroozi/AP Photo)

Onlookers gather around a struggling beached whale in the Yoff neighborhood of Dakar, Senegal Wednesday, May 21, 2008. Residents worked Wednesday morning to save some of the more than 80 whales that were stranded on the beach Tuesday night. This whale was successfully towed out to sea by a fishing boat, though at least 20 others lay dead on the beach by midday Wednesday. (Photo by Rebecca Blackwell/AP Photo)

School children celebrate after being rewarded for their dance performance during India's Independence Day celebrations in Chandigarh, India, August 15, 2015. Indian Prime Minister Narendra Modi's independence day speech focused on measures his “Team India” had rolled out to include millions of poor Indians in the banking and insurance systems, policies for workers and farmers and successes in the fights against inflation and corruption. (Photo by Ajay Verma/Reuters)

The Lumix GX1 single lens reflex (SLR) camera with 14-42 mm powerzoom lens is displayed at the Panasonic booth at the 2012 International Consumer Electronics Show at the Las Vegas Convention Center January 10, 2012 in Las Vegas, Nevada. The new camera comes with an external viewfinder and flash and an ISO up to 12,800. The camera as shown sells for USD 949; the camera body alone is USD 799. (Photo by Ethan Miller/Getty Images)

An East German civilian (L) shows an East German customs officer the contents of his Trabant (auto) at checkpoint Potsdamer Platz in East Berlin in this November 24, 1989 file picture, as East Germany enforcing stringent customs controls to avoid smuggling. (Photo by Reuters)

A migrant smokes a cigarette as he waits among others to cross the Croatian border near the village of Berkasovo, Serbia October 19, 2015. Thousands of migrants clamoured to enter European Union member Croatia from Serbia on Monday after a night spent in the cold and mud of no-man's land, their passage west slowed by a Slovenian effort to impose limits on the flow to western Europe. (Photo by Marko Djurica/Reuters)

A woman poses for pictures with skulls made of cardboard placed on an altar next to the San Francisco church in Mexico City during the celebration of All Souls Day on November 2, 2015. (Photo by Yuri Cortez/AFP Photo)

A newborn grey seal pup is tended by its mother at Donna Nook, a nature reserve on the county’s coastline managed by Lincolnshire Wildlife Trust in Lincolnshire, UK on November 23, 2015. (Photo by David Tipling/Rex Shutterstock)