This undated photo provided by NOAA in May 2018 shows aurora australis near the South Pole Atmospheric Research Observatory in Antarctica. When a hole in the ozone formed over Antarctica, countries around the world in 1987 agreed to phase out several types of ozone-depleting chemicals called chlorofluorocarbons (CFCs). Production was banned, emissions fell and the hole shriveled. But according to a study released on Wednesday, May 16, 2018, scientists say since 2013, there’s more of a banned CFC going into the atmosphere. (Photo by Patrick Cullis/NOAA via AP Photo)

Thai vendors stand next to edible insects for sale at Talad Thai market in Pathum Thani province on the outskirts of Bangkok, Thailand, 15 July 2013. Insects have long been on the menu in Thailand, but academics and the United Nation's Food and Agriculture Organization (FAO) officials are hoping they will become a more common global source of protein and nutrients to meet the need for growing world food requirements in the future. (Photo by Narong Sangnak/EPA)

A Brazilian drug gang member nicknamed Pilintra, 26, poses with a gun atop a hill overlooking a slum in Salvador, Bahia State, April 11, 2013. One of Brazil's main tourist destinations and a 2014 World Cup host city, Salvador suffers from an unprecedented wave of violence with an increase of over 250% in the murder rate, according to the Brazilian Center for Latin American Studies (CEBELA). (Photo by Lunae Parracho/Reuters)

City buildings stand beyond the giant excavated hole left by the Mir mine, a former open pit diamond mine, in Mirny, Russia, on Tuesday, November 12, 2013. OAO Alrosa, the world's largest diamond producer, raised about $1.3 billion in an oversubscribed share sale from investors including Oppenheimer Funds Inc. and Lazard Ltd.'s asset-management unit, First Deputy Prime Minister Igor Shuvalov said. (Photo by Andrey Rudakov/Bloomberg)

Female indigenous players vie for the ball during the final match of Peladao, the amateur football tournament, in Manaus, Amazonas state, Brazil, on November 24, 2013. Peladao is known as the biggest amateur football tournament in the world, with more than 1000 teams competing in various categories since 1973. The indigenous category was created in 2005 and eight teams participated this year. (Photo by Yasuyoshi Chiba/AFP Photo)

Chinese female weightlifter Xiang Yanmei, who competes in the 69 kg weightclass, rests with a weight on her stomach as she checks her phone during a training session in preparation for the Rio Olympics at the Training Center of General Administration of Sports in China on July 20, 2016 in Beijing, China. Xiang Yanmei won the World Championships in 2013 and 2015. (Photo by Kevin Frayer/Getty Images)

A newly-married couple takes a nap before their mass wedding ceremony at the CheongShim Peace World Center in Gapyeong, South Korea, Sunday, February 17, 2013. Some 3,500 South Korean and foreign couples exchanged or reaffirmed marriage vows in the Unification Church's mass wedding arranged by Hak Ja Han Moon, a wife of the late Rev. Sun Myung Moon, the controversial founder of the Unification Church. (Photo by Lee Jin-man/AP Photo)

A snail (Helix Aspersa) and a baby snail sit on a leave in a farm in Vienna June 12, 2013. Andreas Gugumuck owns Vienna's largest snail farm, exporting snails, snail-caviar and snail-liver all over the world. The gourmet snails are processed using old traditional cooking techniques and some are sold locally to Austrian gourmet restaurants. (Photo by Leonhard Foeger/Reuters)