The changing face of Africa

The rapid transformation of the landscape of Africa has been brought into sharp focus by the publication of an atlas by the United Nations Environment Programme.

The 400-page document, also published online, highlights major changes in each of the continent's nations.

Here are a few of the key features.

RWENZORI MOUNTAINS, UGANDA

Climate change has caused the glaciers in this Ugandan equatorial mountain range to shrink dramatically. The UN says they halved in size between 1987 and 2003 (there are fewer white areas on the second image), during which time higher temperatures and decreasing cloud cover also have contributed to sublimation - direct vaporisation of ice without melting.

According to the UN, researchers believe that, at the current rate of reduction, they will have disappeared within 20 years.

RAINFOREST, DEMOCRATIC REPUBLIC OF CONGO

The growing road network in the north of the country has had a noticeable impact on the rainforest, with the prospect of more traffic still in the biologically rich environment. The light green corridors in the 1975 image show the deforestation along the local roads of Nord-Ubangi and Mongala provinces.

In the 2003 image, they have clearly widened, largely as a result of agricultural changes and industrial logging which the UN says has now become the most extensive form of land use in central Africa.

JEBEL MARRA FOOTHILLS, SUDAN

Western Sudan's growing population, fuelled partly by people fleeing drought and conflict in Darfur, has eroded much of the shrubbery and many of the trees in this region's fragile environment.

The loss of open-savannah woodlands since 1972 - on the left hand side of the images - is having a substantial impact on life in the region, with degradation of land hampering the scope for supporting the ever-increasing population.

EXPANSION OF DAKAR, SENEGAL

In half a century, the Senegalese capital has mushroomed from a small urban settlement on the tip of the peninsula to a large metropolis containing 2.5m people.

The right-hand image does not even show the full extent of contemporary Dakar. Urban sprawl has eaten up much of the prime farmland that has historically supported it.

Extreme drought in the country in the 1960s drove hundreds of thousands of people out of rural areas and into the city. By 2030, two-thirds of Senegal's population is expected to be urban. Although birth rates have begun to decline, the city continues to grow.