Merit Prize Winner: “A Well Earned Rest in the Sahara”. This photo of Moussa Macher, our Tuareg guide, was taken at the summit of Tin-Merzouga, the largest dune (or erg) in the Tadrat region of the Sahara desert in southern Algeria. Moussa rested while waiting for us to finish our 45-minute struggle to the top. It only took ten minutes of rolling, running, and jumping to get back down. The Tadrat is part of the Tassili N'Ajjer National Park World Heritage area, famous for its red sand and engravings and rock paintings of cattle, elephants, giraffes, and rhinos that lived there when the climate was milder. Photo location: Summit of Tin-Merzouga, Tadrat, Tassili N'Ajjer National Park, Algeria. (Photo and caption by Evan Cole/National Geographic Photo Contest)

Caroline Wozniacki of Denmark serves to Alisa Kleybanova of Russia during the BNP Paribas Open at the Indian Wells Tennis Garden on March 15, 2011 in Indian Wells, California. (Photo by Matthew Stockman/Getty Images)

A Christmas Tree goes up in flames in a controlled-setting demonstration by the Glendale Fire Department on December 13, 2023, in Glendale, California. Firefighters showed how quickly a dried-out tree can ignite. According to the National Fire Protection Administration, Christmas trees account for hundreds of fires each year, often ignited by shorts in electrical lights or open flames from candles, lighters or matches. (Photo by Frederic J. Brown/AFP Photo)

Twin brothers Keith (L) and Deano Stapleton (R) interact with one another as people gather to witness the winter solstice on December 21, 2022 in Newgrange, Ireland. Crowds are gathering at Newgrange in Co Meath, this morning for the winter solstice – the astronomical phenomenon that marks the shortest day and the longest night of the year. Newgrange is a Stone Age (Neolithic) monument in the Boyne Valley, County Meath, it is the jewel in the crown of Ireland's Ancient East and was constructed approximately 5,200 years ago (3,200 B.C.) which makes it older than Stonehenge and the Great Pyramids of Giza. (Photo by Charles McQuillan/Getty Images)

Students from the Liceo Parini school celebrate the end of term in Milan, Italy on June 6, 2024. (Photo by Marco Ottico/LaPresse/Rex Features/Shutterstock)

Climate change activist Greta Thunberg reacts during a news conference during COP25 climate summit in Madrid, Spain, December 9, 2019. (Photo by Juan Medina/Reuters)

Sunset at Walakiri Beach, Sumba in East Nusantenggara, Indonesia in 2019. (Photo by Aries Hendrick Apriyanto/Rex Features/Shutterstock)

Huang Mei-ya in a scene from Lunar Halo by Cloud Gate at Sadler's Wells in London in the last decade of November 2023. (Photo by Tristram Kenton/the Guardian)