365 Days of Climate Awareness 228 – Africa

Africa is a continent which covers 30.3 million km²/11.7 million mi², stretching across the equator from roughly 37°N to 34°S latitude, and from 52°E to 17°W longitude. 1.3 billion people, about 16% of the planet’s total population, live there. It forms the southern coast of the Mediterranean sea, approaching to within 13 km/8 mi of Spain in the Straits of Gibraltar in the west, and connecting to Arabia via the Isthmus of Suez in the east. Contrary to popular conception, the southernmost point of Africa, where the dividing line begins between Atlantic and Indian Oceans, is Cape Agulhas. The Cape of Good Hope is farther north and west.

Physical and political map of Africa.

Africa is considered by most anthropologists to be the cradle of the human race. Africa formed the heart of the ancient continent of Gondwana, which sat across the equator and was tremendously biodiverse. 140 million years have passed since Gondwana broke up but Africa has maintained its position in the tropics, and so has remained biologically abundant. Hominids appeared about 7 million years ago, and remains of Homo sapiens dating to 300,000 years ago have been found all over the continent.

Africa's position within Gondwana, 200 MYA.

Simplified bedrock map.

Geologically Africa is composed of four mineral-rich cratons, ancient igneous and metamorphic rock masses 3.5 billion years or older, within the larger continental mass. There are no subduction zones in or around the continent, making it quiet tectonically, except for the rift valley in the east which, if it continues rifting, will eventually separate the horn into a narrow continental strip somewhat like Madagascar. (The East African rift continues north through the Red Sea into the Jordan River rift valley, which includes the Dead Sea.)

East African Rift Valley. The spreading system extends up through the Red Sea and Jordan River valleys. Fun fact: the Mississippi River Valley and much of the Great Lakes basins are failed rifts!

The northern continent is dominated by the Sahara, the world’s largest desert outside of the Arctic and Antarctic (making it the world’s largest “hot” desert). South of that is the Sahel, the semiarid grassy transition from desert to savanna further south. The savanna is grassy, with more trees, and transitions into the equatorial rainforest. Continuing further south the climate becomes drier (except for the east coast) and cooler, with desertlike conditions on the southwest portion of the continent, arid south central, and savanna in the southeast.

There are 54 countries in Africa, with thousands of spoken languages. Much of the continent is not economically developed, due partly to the difficulties of geography, with the desert and rainforest, and more recently due to  of the slave-gathering and colonial practices of European countries and the United States.  It is estimated that as many as 50% of the continent’s population lives in economic poverty. Economic development has been spotty and uneven, with some countries like Nigeria and Kenya becoming more industrialized but failing to spread that prosperity to much of their populace.  Especially in areas like Nigeria, the influence of western economies exploiting the region’s oil resources remain an ongoing part of the social problems.

Tomorrow: overview of the African climate.

Be brave, and be well.