Children hold signs thanking truck drivers hauling rocks to the Lake Oroville Dam after an evacuation was ordered for communities downstream from the dam in Oroville, California, U.S. February 13, 2017. (Photo by Jim Urquhart/Reuters)

Women carry gas cylinders to fill them at a distribution point in Cairo January 19, 2015. Egypt is going through its worst energy crisis in decades and is seeking fresh sources of natural gas, which powers most of its homes and factories. (Photo by Mohamed Abd El Ghany/Reuters)

A 2.4 kg chicken is pictured next to 14,600,000 bolivars, its price and the equivalent of 2.22 USD, at a mini-market in Caracas, Venezuela on August 16, 2018. It was the going price at an informal market in the low-income neighborhood of Catia. (Photo by Carlos Garcia Rawlins/Reuters)

A woman selling souvenirs walks through Kuta beach in Bali June 5, 2008. Indonesia is expected to report tourist arrivals in December this week. (Photo by Murdani Usman/Reuters)

People protest for greater action against climate change during the People's Climate March on September 21, 2014 in New York City. The march, which calls for drastic political and economic changes to slow global warming, has been organized by a coalition of unions, activists, politicians and scientists. (Photo by Andrew Burton/Getty Images)

An ice covered entrance door to the international gene bank Svalbard Global Seed Vault (SGSV) near Longyearbyen on Spitsbergen, Norway, October 20, 2015. Two consignments of crop seeds will be deposited next year in a “doomsday vault” built in an Arctic mountainside to safeguard global supplies. The vault, which opened on the Svalbard archipelago in 2008, is designed to protect crop seeds, such as beans, rice and wheat against the worst cataclysms of nuclear war or disease. (Photo by Anna Filipova/Reuters)

Student, Shoukria positions a stone for cutting at the Turquoise Mountain Gem cutting class on May 18, 2011, in Kabul, Afghanistan. The mineral resources of Afghanistan are relatively unexplored even with Afghanistan's mineral wealth of coal, copper, gold and iron ore, with precious and semiprecious stones, including high-quality emerald, lapis lazuli, red garnet and ruby. Given the country's remote and rugged terrain, on-going instability plus an inadequate infrastructure and transportation means that mining is still difficult. While many are trying to bring positive changes, Afghanistan's mining industry uses unregulated, primitive methods and outdated equipment. (Photo by Paula Bronstein/Getty Images)

A protester clashes with a police officer in Athens' central Syntagma (Constitution) Square in this June 15, 2011 file photo. Greece triggered the regional financial crisis in 2009 when a far higher budget deficit than previously calculated emerged. The collapse of talks with creditors in Paris last November set off a month-long sequence of events leading to elections this week and proving Greece is still the region's weak link. The vote is expected to be won by Syriza, a far-left party opposed to the bailout, worrying investors and creditors alike. (Photo by Yannis Behrakis/Reuters)