The Tibetan Plateau, the highest and largest plateau above sea level, is one of the harshest environments settled by humans. It has a cold and arid environment and its elevation often surpasses 4000 meters above sea level (masl). The plateau covers a wide expanse of Asia—approximately 2.5 million square kilometers—and is home to over 7 million people, primarily belonging to the Tibetan and Sherpa ethnic groups.