A tourist stands at an edge of the singing sand, the 150-metre-high by three-kilometre-long dune that generates a low-pitched, organ-like rumble in dry weather, in Altyn-Emel national park in Almaty region, Kazakhstan, May 12, 2016. (Photo by Shamil Zhumatov/Reuters)

People swim underwater at Clovelly Beach on December 14, 2023 in Sydney, Australia. A severe heat wave hit Sydney over the weekend, a precursor of hot and dry conditions expected for the rest of the summer which will also bring heightened bushfire risk. The mercury rose to alarming levels again on Thursday. (Photo by Jenny Evans/Getty Images)

An Indian one-horned rhinoceros grazes on a dry wetland at the Pobitora Wildlife Sanctuary on the southern bank of the Brahmaputra River in Morigaon district of India's Assam state on April 4, 2025. (Photo by Biju Boro/AFP Photo)

The iconic Otley Run starts at Woodies pub in Far Headingly and finishes at The Dry Dock at the edge of Leeds, UK city centre on August 24, 2025. Hundreds of rowdy drinkers take to the streets this weekend. (Photo by NB Press LTD)

Revelers take a selfie during a Holi Festival in Madrid, Spain, Sunday, April 26, 2015. The festival is based on the Hindu spring festival Holi, also known as the festival of colours where participants colour each other with dry powder and coloured water. (Photo by Andres Kudacki/AP Photo)

Early-risers take part in an exercise program at dawn in Bug Light Park, Wednesday, September 20, 2023, in South Portland, Maine. Most of the state is enjoying a pleasant, dry stretch of weather that should last through Saturday. (Phoot by Robert F. Bukaty/AP Photo)

Wedges of an orange generate enough current and electrical juice – 3.5 volts – to power an LED. The fruit’s citric acid helps electrons flow from galvanized nails to copper wire in this 14-hour exposure. This image was published in September’s Visions of Earth, a trio of photos that appear in each issue of National Geographic. (Photo by Caleb Charland/National Geographic)