The sun rises through the thick fog that covers the city of Frankfurt, Germany, Friday, November 12, 2021. (Photo by Michael Probst/AP Photo)

A woman crosses the street on a foggy morning in Frankfurt, Germany, Friday, October 29, 2021. (Photo by Michael Probst/AP Photo)

Participants at the Dubai Run at Sheikh Zayed Road in Dubai, United Arab Emirates on November 26, 2021. (Photo by Ruel Pableo for The National)

Horizontal lightning was captured in this picture taken over an hour in Ensenada, Mexico on October 28, 2021. (Photo by Edgar Lima/Animal News Agency)

A lion rests in the Nairobi National Park, Kenya on January 6, 2021. (Photo by Tiksa Negeri/Reuters)

Palestinian children practise parkour along a beach in Gaza City at sunset on January 27, 2021. (Photo by Mohammed Abed/AFP Photo)

A tree covered with hoarfrost casts a shadow on a snowy field, shot with a drone in Sieversdorf-Hohenofen, Germany on January 31, 2021. (Photo by Patrick Pleul/dpa)

A stunt rider performs on the wooden wall during a fair in Bogra, Bangladesh, February 10, 2021. (Photo by Xinhua News Agency/Rex Features/Shutterstock)