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)

A picture taken with a drone shows the giant landart painting entitled “Message From Future” by French artist Saype in the park “La Perle du Lac” in Geneva, Switzerland, 16 September 2018 (issued 17 September). The artwork covering 5,000 square meters was produced with biodegradable paints made from natural pigments. The artist called the little girl “Future” as a symbol of the generations from the future and the small origami boats that she drops into Lake Geneva aims to represent a message of hope sent to the world. (Photo by Valentin Flauraud/EPA/EFE)

Police officers laugh as Greenpeace activists create a burnt smoldering rain-forest with a lifelike animatronic orangutan at the headquarters of Oreo cookies, in protest over their use of palm oil on November 19, 2018 in Uxbridge, England. Greenpeace is calling on the makers of Oreo to stop buying palm oil from Wilmar, the largest palm oil producer, who they say have destroyed 70,000 hectares of Indonesian rain forest in the last two years. (Photo by Chris J. Ratcliffe for Greenpeace via Getty Images)

A member of the riot police gets ready to repel the attacks of protesters during a protest against President Sebastian Piñera during the seventh day of protests against President Sebastian Piñera on October 24, 2019 in Santiago, Chile. Although President Sebastian Piñera announced measures to improve equality, unions called for a national strike and demonstrations continue as casualties are now at least 18. Demands behind the protest include issues like health care, pension system, privatization of water, public transport, education, social mobility and corruption. (Photo by Marcelo Hernandez/Getty Images)

A woman tries to cross a flooded street as people walk on a trestle bridge during high water, in Venice, northern Italy, Friday, November 15, 2019. Exceptionally high tidal waters returned to Venice on Friday, prompting the mayor to close the iconic St. Mark’s Square and call for donations to repair the Italian lagoon city just three days after it experienced its worst flooding in 50 years. (Photo by Andrea Merola/ANSA via AP Photo)

Palestinians scuffle with Israeli forces at Damascus Gate in Jerusalem's Old City on December 8, 2017. Palestinians clashed with Israeli security forces after calls for a “day of rage” as US President Donald Trump's declaration of Jerusalem as Israel's capital sent shockwaves through the region for a second day. (Photo by Thomas Coex/AFP Photo)

People stand near beached sperm whales on January 13, 2016, after they became stranded on the Dutch island of Texel the day before. Five sperm whales which became stranded on Texel have died, officials said January 13. Experts said the beached whales had already been badly injured and their chances of survival were poor. Volunteers tried to save them but called off their efforts late in the night because of bad weather and darkness, ANP news agency said. (Photo by Remko de Waal/AFP Photo/ANP)

A pro-democracy demonstrator fights with a Soviet soldier on top of a tank parked in front of the Russian Federation building on August 19, 1991, after a coup toppled Soviet President Mikhail Gorbachev. The same day, thousands in Moscow, Leningrad, and other cities answered Russian Republic President Boris Yeltsin's call to raise barricades against tanks and troops. (Dima Tanin/AFP/Getty Images)