Africa is the world's second-largest and second-most-populous continent. At about 30.2 million km² (11.7 million sq mi) including adjacent islands, it covers six percent of the Earth's total surface area and 20.4 percent of the total land area. It has 54 fully recognized sovereign states, 9 territories and three de facto states with limited recognition. The indigenous people of Africa are those people of Africa whose way of life, attachment or claims to particular lands, and social and political standing in relation to other more dominant groups have resulted in their substantial marginalisation within modern African states. Indigenous people of Africa include the Amazigh (or Imazighn) of North Africa, commonly know as the Berbers; the Ogiek, Sengwer, Dahalo – Aweer – Waata, Elmolo, Yaaku, Maasai, Samburu, Rendille, Pokot, Pokomo, Borana, Hadzabe, Dorobo and others of East Africa; the Batwa, Bambuti, and others of Central Africa; the Dinka, Nuer, Afar, Boranna, Karamajong, Mbororo, Tuareg, and others of the Horn of Africa; the San, Khoekhoe, Nama, and others of South Africa; and Bororo, Tuareg, Tubu, and others of West Africa. Like their indigenous brothers and sisters, they face a number of common struggles: sovereignty, the right to self-determination, preservation of language and heritage, rights to land and natural resources, impacts from climate change and environmental damage, and recognition within local, federal, and international governments and laws.