Sandstone sculpted by water and wind erosion is seen in a slot canyon, one of hundreds that surround Lake Powell near Page, Arizona, May 26, 2015. Lake Powell on the Colorado River provides water for Nevada, Arizona and California. A severe drought in recent years, combined with withdrawals that many believe are not sustainable, has reduced its levels to only about 42 percent of its capacity. (Photo by Rick Wilking/Reuters)

An Egyptian actress working at the Pharaonic Village simulates ancient agriculture scenes during a show marking Sham el-Nessim, or “smelling the breeze”, in Giza, Egypt, Monday, April 13, 2015. The holiday signifies the arrival of Spring, a uniquely Egyptian tradition practiced since the days of the Pharaohs. (Photo by Amr Nabil/AP Photo)

Girls play in the makeshift refugee camp at the northern Greek border point of Idomeni, Greece, Thursday, March 17, 2016. Leaders of the EU's 28 divided nations reconvene in Brussels in hopes of ironing out disagreements on a proposed agreement with Turkey in the migrants crisis. (Photo by Vadim Ghirda/AP Photo)

LiLou the therapy pig stands in front of a departures board at San Francisco International Airport in San Francisco, California, U.S. October 4, 2019. (Photo by Jane Ross/Reuters)

Children play in water to beat the heat during the Muslim holy month of Ramadan amid lockdown of the Sindh province due to the ongoing coronavirus COVID-19 disease pandemic in Karachi, Pakistan, 28 April 2020. Muslims around the world celebrate the holy month of Ramadan, by praying during the night time and abstaining from eating, drinking, and sexual acts during the period between sunrise and sunset. Ramadan is the ninth month in the Islamic calendar and it is believed that the revelation of the first verse in Koran was during its last 10 nights. (Photo by Shahzaib Akber/EPA/EFE)

This photo taken November 10, 2015 shows homeless street children sleeping in a park in Manila. The Philippines has swept 20,000 homeless from the streets, cancelled hundreds of flights and declared public holidays in Manila to ensure a safe and efficient summit of 21 world leaders next week, officials say. (Photo by Jay Directo/AFP Photo)

Fallen leaves cover the undergrowth as a commuter on a bicycle makes her way through the Tiergarten park in central Berlin on December 7, 2020. (Photo by Odd Andersen/AFP Photo)