Jockeys spur buffalos during the Makepung buffalo races at Jembrana in Bali, Indonesia on October 23, 2016. Makepung is a tradition for farmers to celebrate a bumper harvest in Bali. (Photo by Kadek Raharja/Xinhua/Barcroft Images)

Crowds watch surfers as the first big swell of the year arrives in Nazaré, Portugal on October 28, 2015. (Photo by Pedro Miranda/Demotix/Corbis)

Natalie Dormer attends the mtvU Fandom Awards at MTV Fan Fest at Comic-Con, July 24, 2014, in San Diego. (Photo by Jordan Strauss/Invision for MTV/AP Images)

Bride Yulia Tagil sits on the backseat of a bike as she arrives for her alternative wedding ceremony on a square in Tel Aviv July 25, 2010. The alternative wedding ceremony was intended to demonstrate against the current situation in Israel, where the only way for Jews to get married by law is through the Chief Rabbinate. (Photo by Nir Elias/Reuters)

Growing cities, overuse of fertilizers and factory wastewater have degraded China's water supplies to the extent that half the nation's rivers and lakes are severely polluted. China aims to spend $850 billion to improve filthy water supplies over the next decade, but even such huge outlays may do little to reverse damage caused by decades of pollution and overuse in Beijing's push for rapid economic growth. Photo: Fishermen row a boat in the algae-filled Chaohu Lake in Hefei, Anhui province, June 19, 2009. (Photo by Jianan Yu/Reuters)

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)

People take pictures of 30 Rockefeller Plaza as it is lit in the colors of the Democratic and Republican parties ahead of the U.S presidential election in Manhattan, New York, U.S., November 7, 2016. (Photo by Andrew Kelly/Reuters)

The northern lights, or aurora borealis, illuminate the sky over Flakstad beach on Lofoten Islands in the Arctic Circle on September 5, 2017. (Photo by Jonathan Nackstrand/AFP Photo)