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)

Turkana tribesmen walk with guns to protect their cattle from rival tribes near Baragoy, Kenya August 4, 2017. (Photo by Goran Tomasevic/Reuters)

Drunk fresher is helped by students as she falls to the ground on night out at during the alcohol-fuelled Freshers’ Week in Birmingham, United Kingdom on September 18, 2017. Freshers are inducted during Freshers' Week – the first week of the Academic year – one of the busiest and most fun weeks of the year. (Photo by Caters News Agency)

Cloud inversion taken at Sunrise in Mam Tor, Derbyshire, UK on August 30, 2016. (Photo by David Zdanowicz/REX Shutterstock)

Secondary school graduates play in a fountain as they celebrate the last day of school, traditionally called the “last bell” in central Kiev, Ukraine on May 31, 2019. (Photo by Valentyn Ogirenko/Reuters)

A Sudanese man plays a local music instrument ahead of a meeting with Mohamed Hamdan Dagalo, also known as Himediti, deputy head of Sudan's ruling Transitional Military Council (TMC) and commander of the Rapid Support Forces (RSF) paramilitaries, in the capital Khartoum on June 18, 2019. (Photo by AFP Photo/Stringer)

A nurse bows to the life size statue of Pope Francis as her friend takes a photograph at the St.Louis hospital in Bangkok, Thailand, Tuesday, November 19, 2019. Pope Francis arrives in Thailand on Wednesday for the first visit here by the head of the Roman Catholic Church since St. John Paul II in 1984. (Photo by Manish Swarup/AP Photo)

Swedish climate change activist Greta Thunberg, Isabelle Axelsson and German Luisa Neubauer take part in a climate strike protest during the 50th World Economic Forum (WEF) annual meeting in Davos, Switzerland on January 24, 2020. (Photo by Denis Balibouse/Reuters)