African humid periodThe African humid period (AHP; also known by other names) is a climate period in Africa during the late Pleistocene and Holocene geologic epochs, when northern Africa was wetter than today. The covering of much of the Sahara desert by grasses, trees and lakes was caused by changes in the Earth’s axial tilt; changes in vegetation and dust in the Sahara which strengthened the African monsoon; and increased greenhouse gases. During the preceding Last Glacial Maximum, the Sahara contained extensive dune fields and was mostly uninhabited.
Tibesti MountainsThe Tibesti Mountains are a mountain range in the central Sahara, primarily located in the extreme north of Chad, with a small portion located in southern Libya. The highest peak in the range, Emi Koussi, lies to the south at a height of and is the highest point in both Chad and the Sahara. Bikku Bitti, the highest peak in Libya, is located in the north of the range. The central third of the Tibesti is of volcanic origin and consists of five volcanoes topped by large depressions: Emi Koussi, Tarso Toon, Tarso Voon, Tarso Yega and Toussidé.
DesertA desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the land surface of the Earth is arid or semi-arid. This includes much of the polar regions, where little precipitation occurs, and which are sometimes called polar deserts or "cold deserts".
AgadezAgadez (Air Tamajeq: ⴰⴶⴰⴷⴰⵣ, Agadaz), formerly spelled Agadès, is the fifth largest city in Niger, with a population of 110,497 based on the 2012 census. The capital of Agadez Region, it lies in the Sahara desert, and is also the capital of Aïr, one of the traditional Tuareg–Berber federations. The historic centre of the town has been designated a World Heritage Site by UNESCO. Sultanate of Aïr Agadez was founded before the 14th century, and, by growing around trans-Saharan trade, gradually became the most important city of the Tuareg people, supplanting Assodé.
NigerNiger or the Niger (niːˈʒɛər,_ˈnaɪdʒər , niʒɛʁ), officially the Republic of the Niger (République du Niger; Jamhuriyar Nijar), is a landlocked country in West Africa. It is a unitary state bordered by Libya to the northeast, Chad to the east, Nigeria to the south, Benin and Burkina Faso to the southwest, Mali to the west, and Algeria to the northwest. It covers a land area of almost , making it the largest landlocked country in West Africa. Over 80% of its land area lies in the Sahara.
SaharaThe Sahara (səˈhɑːrə, səˈhærə) is a desert on the African continent. With an area of , it is the largest hot desert in the world and the third-largest desert overall, smaller only than the deserts of Antarctica and the northern Arctic. The name "Sahara" is derived from the Arabic word for "desert" in the feminine irregular form, the singular (صحراء //ˈSaHra), plural (صَحَارَى //ˈSaHaaraa), (صَحَار), (صَحْرَاوَات), (صَحَارِي).
