As an airliner prepares to land, a bird takes off at the Gravelly Point park near Reagan National Airport in Arlington, Va. on December 23, 2018. (Photo by Michael S. Williamson/The Washington Post)

Over 30 Douglas C-47 Skytrains (Dakotas) making final preparations for flight formation practice before the 75th D-Day Anniversary flight to Normandy in Duxford, England on June 4, 2019. (Photo by UK Air Force Images)

Londoners enjoying the magnificent sight of sun setting perfectly in the middle of London Eye as seen from Greenwich Park in London, England on the warmest day of the year on April 19, 2018. (Photo by London Viewpoints/Rex Features/Shutterstock)

Michelle Rodriguez attends the European Premiere of “Widows” and opening night gala of the 62nd BFI London Film Festival on October 10, 2018 in London, England. (Photo by James Gourley/Rex Features/Shutterstock)

Vehicles pass through the heavy fog and air pollution that cover Skopje valley in the early morning, in Skopje, The Former Yugoslav Republic of Macedonia, 14 December 2017. According to media reports, Skopje is considered one of the most polluted cities in the world. (Photo by Georgi Licovski/EPA/EFE)

An artist gets ready backstage to perform an Indian art form of dance called “Ottamthullal” at the annual eight-day long Vrischikolsavam festival, which features a colourful procession of decorated elephants along with drum and trumpets concerts, at Sree Poornathrayeesa temple in Kochi, India, December 7, 2018. (Photo by Sivaram V/Reuters)

A man stands by an installation depicting “2019” in the Red Square in Moscow, Russia on December 17, 2018. (Photo by Maxim Shemetov/Reuters)

A man stands near smoke billowing from a brick kiln in Karachi, Pakistan, 14 December 2018. According to the UN report, carbon dioxide (CO2) emissions have increased for the first time in four years. The United Nations Conference COP24, held in Katowice, Poland, until 14 December 2018, searches for a common position in the fight against climate change. (Photo by Shahzaib Akber/EPA/EFE)