Lake Magadi, Kenya – Yann Arthus-Bertrand Photo

Lake Magadi is located on a fault of the East African Rift Valley, and contains an exceptional concentration of caustic sodium carbonate, produced naturally by the transformation of the sediments when water entering the lake comes into contact with the molten lava under the lake. The soda concentration is so strong and the lake so shallow that a thick crust of soda crystals partly covers it, giving rise to the oldest mining firm in Kenya, the Magadi Soda Company, founded at the beginning of the twentieth century. Once upon a time the lake’s water was fresh like that of its neighboring lakes, Naivasha and Baringo. It was inhabited by hippopotami, crocodiles, and fish. All that survives today is a limited fauna of microscopic fish and primitive algae that attracts flamingoes. However, the flamingoes are actually threatened by the soda. When it does not rain enough, the lake dries and what water remains turns into a thick soda gel; it solidifies around the feet of the chicks, which then can only be rescued by the national parks service teams. Changes to the planet’s character are thus not merely the handiwork of the sorcerer’s apprentice, man. There is also a natural, autonomous dynamic, in which volcanoes, among other natural phenomena, play an essential role.