Labourers pour molten iron into a container at a foundry in Xiangfan, Hubei province in this July 2, 2010 file photo. Iron ore is enjoying its biggest rally in years, outpacing copper and oil so far in 2016, but still weak forward prices show it may be tough to stretch the bullish outlook. Improving steel prices in top market China are helping fuel iron ore's climb as producers gear up for a seasonal uptick in demand. Yet there is no shortage of doubters who see gains in the bulk commodity as fleeting given a large glut and challenges for China's economy. (Photo by Reuters/Stringer)

NASA's DHC-3 Otter plane flies in Operation IceBridge-Alaska surveys of mountain glaciers in Alaska in this image released on September 18, 2014. Over the past few decades, average global temperatures have been on the rise, and this warming is happening two to three times faster in the Arctic. (Photo by Chris Larsen/Reuters/NASA/University of Alaska-Fairbanks)

People celebrate France' s victory in the Russia 2018 World Cup final football match between France and Croatia, on July 15, 2018 in Toulouse' s city centre. (Photo by Eric Cabanis/AFP Photo)

People cheer as the ball drops at midnight in Times Square on January 1, 2015 in New York City. An estimated one million people from around the world are expected to pack Times Square to ring in 2015. (Photo by Andrew Theodorakis/Getty Images)

Dancers from the “Legend Lin Dance Theatre” perform the artistic director and choreographer Li-chen Lin's classic works “Hymne aux Fleurs qui Passent, Anthem to the Fading Flowers” during a rehearsal at the National Theater Concert Hall in Taipei, Taiwan, Tuesday, August 18, 2015. “Hymne aux Fleurs Qui Passent” pays tribute to the cycle of the year and the complementary principles of Yin and Yang whose eternal struggle provides the driving force behind the changing of the seasons. (Photo by Chiang Ying-ying/AP Photo)

Fashionistas pose for photographs in front of a homeless man outside Moynihan Station following a showing of the Rag & Bone Spring/Summer 2013 collection during New York Fashion Week in this September 7, 2012 file photo. (Photo by Lucas Jackson/Reuters)

Kha Tu Ngoc rests in her two- square- meter house in Ho Chi Minh City on May 2, 2018. The “micro- house” dwellings are dotted throughout Vietnam' s bustling southern hub, occupied by families clinging to postage stamp- sized plots a city developing at breakneck pace. Tucked away in winding alleys, nestled under new condo developments or sandwiched between street food stalls and shops, the tiny houses are easily missed by the unattentive passerby. (Photo by Thanh Nguyen/AFP Photo)

The Jet Propulsion Lab team's RoboSimian robot turns on a valve at a simulated disaster-response course during day one of the Defense Advanced Research Projects Agency (DARPA) Robotics Challenge finals in Pomona, California, June 5, 2015. (Photo by David McNew/Reuters)