In this November 12, 2015, file photo, Mt. Everest is seen from the way to Kalapatthar in Nepal. An American climber has died near the summit of Mount Everest and an Indian climber is missing after heading down from the mountain following a successful ascent, expedition organizers said Sunday. (Photo by Tashi Sherpa/AP Photo)

A South Korean marine in action during their regular drill on Yeonpyeong Island, South Korea November 1, 2018. (Photo by Jeon Heon-Kyun/Pool via Reuters)

Cooler temperatures begin this week as a polar vortex brings much colder conditions with the chance of snow for Snowdonia, Ogwen Valley, North Wales on 22nd October 2018. The Ogwen Valley and Tryfan Mountain looking splendid in the Autumn sunrise. (Photo by DGDImages/Alamy Live News)

Sukhoi Su-30SM jet fighters of the Russkiye Vityazi (Russian Knights) aerobatic team perform during a demonstration flight in Krasnoyarsk, Russia October 6, 2018. (Photo by Ilya Naymushin/Reuters)

A member of Korean Federation for Environmental Movement in a Santa Claus outfit attaches dumped cigarette butts at a cigarette butt Christmas tree in front of Korea Tobacco & Ginseng Corporation office in Seoul, South Korea, Monday, December 23, 2019. The environmental activist group called for a ban on the use of plastic for cigarette filters as part of efforts to protect the environment from toxic plastic pollution. (Photo by Ahn Young-joon/AP Photo)

A couple enjoys the view of the ethnographic and amusement center Kremlin in Izmailovo reflected in the Serebryano-Vinogradnii lake in Moscow, Russia on July 30, 2017. (Photo by Mladen Antonov/AFP Photo)

Visitors are seen with giraffes on a bus at Safari Park in Kanchanaburi Province, Thailand, January 19, 2020. Kanchanaburi in western Thailand an area known for its waterfalls and caves. (Photo by Rachen Sageamsak/Xinhua News Agency/Eyevine)

Rajesh Babu, a police officer, wearing a helmet depicting coronavirus, requests a commuter to stay at home during a 21-day nationwide lockdown to limit the spreading of coronavirus disease (COVID-19), in Chennai, India, March 28, 2020. (Photo by P. Ravikumar/Reuters)