An employee sorts waste at the Wecycler recycling centre in Ebutte Meta district in Lagos, Nigeria July 28, 2016. (Photo by Akintunde Akinleye/Reuters)

A South China Tiger cub meets public at Guangzhou Zoo on June 22, 2017 in Guangzhou, Guangdong Province of China. Guangzhou Zoo boasts of the successful breeding of South China Tiger cub after 15 years. (Photo by VCG/VCG via Getty Images)

Pedestrians cross a road in Cape Town, South Africa Saturday, March 28, 2020, as South Africa went into a nationwide lockdown for 21 days in an effort to control the spread of the coronavirus. (Photo by Nardus Engelbrecht/AP Photo)

A 20 metre high spiral staircase in a tower used as an emergency exit, is seen inside a Federal Reserve bank (Bundesbank) bunker, prior to the bunker's official opening to the public in Cochem, Germany, March 18, 2016. West Germany's Central Bank (Deutsche Bundesbank) stored some 20 billion German marks of emergency notes in two underground bunkers, one in Frankfurt the other in Cochem, between 1964-1988 during the cold war. (Photo by Kai Pfaffenbach/Reuters)

Snow blows off the Svalbard Global Seed Vault before being inaugurated at sunrise, Tuesday, February 26, 2008. (Photo by John McConnico/AP Photo)

A long exposure photograph shows a tree burning during the Kincade fire off Highway 128, east of Healdsburg, California on October 29, 2019. California braced on October 29 for the most powerful winds this season that threaten to spread destructive fires raging in the state and could spark new blazes. (Photo by Philip Pacheco/AFP Photo)

Beach goers sunbath inside a new large scale interactive art work by artist Gregor Schneider entitled “Bondi Beach” at Sydneys Bondi Beach on September 28, 2007 in Sydney, Australia. (Photo by Sergio Dionisio/Getty Images)

A small section of the expanding remains of the Veil Nebula, a massive star that exploded about 8,000 years ago. The entire nebula is 110 light-years across, covering six full moons on the sky as seen from Earth, and resides about 2,100 light-years away in the constellation Cygnus, the Swan. (Photo by Reuters/NASA/ESA/Hubble)