Africa

Africa, like other continents, has been subjected to gyrating swings in climate during the Quartenary period of the last 2 million years. These climatic changes have had dramatic affects on landforms and vegetation. Some of these cyclical changes may have been driven by cosmic or astronomical phenomena including asteroid and comet collisions.

But the impact of humankind upon the African environment has been radical and undeniable. Beginning 2,000 years ago and accelerating to our present day, African woodland belts have been deforested. Such environmental degradation has been exacerbated by over-grazing, agricultural abuse, and man-made climatic change, including possible global warming caused by the buildup of man-made carbon dioxide, chlorofluorocarbons (CFCs) and other greenhouse gases.

Deforestation, desertification, and soil erosion pose threats to Africa's man-made lakes and thereby Africa's hydroelectric capacity. Africa's multiplying and undernourished populations exert ever greater demands on irrigated agriculture but the continent's water resources are increasingly taxed beyond their limits. To stabilize Africa's ecology and safeguard its resources and mineral wealth, many earth scientists say greater use must be made of sustainable agricultural and pastoral practices. Progress in environmental and resource management, as well as population control is also vital.