It was long shrouded in mystery, called "the Dark Continent" by Europeans in awe of its massive size and impenetrable depths. Then its wondrous natural riches were revealed to the world. Now a third image of Africa and its environment is being laid before us – one of destruction on a vast and disturbing scale.
Using "before and after" satellite photos, taken in all 53 countries, UN geographers have constructed an African atlas of environmental change over the past four decades – the vast majority of it for the worse.
In nearly 400 pages of dramatic pictures, disappearing forests, shrinking lakes, vanishing glaciers and degraded landscapes are brought together for the first time, providing a deeply disturbing portfolio of devastation.
The atlas, compiled by the United Nations Environment Programme (UNEP) at the request of African environment ministers, and launched yesterday simultaneously in Johannesburg and London, underlines how extensively development choices, population growth, regional conflicts and climate change are impacting on the natural world and the nature-based assets of the continent.
The satellite photos, some of them spanning a 35-year period, offer striking snapshots of environmental transformation in every country.
The purpose of the atlas is to inspire African governments to improve their records as environmental custodians, and as such, its language and tone are studiously neutral, generally referring to environmental "change" rather than destruction. But although there are some examples given of change for the better, the vast majority of the case studies are of large-scale environmental degradation, and the atlas compilers freely accept that this represents the true picture.
They write of "the swell of grey-coloured cities over a once-green countryside; protected areas shrinking as farms encroach upon their boundaries; the tracks of road networks through forests; pollutants that drift over borders of neighbouring countries; the erosion of deltas; refugee settlements scattered across the continent causing further pressure on the environment; and shrinking mountain glaciers."
For its visual impact, the atlas takes advantage of the latest space technology and Earth observation science, including the 36-year-old legacy of the US Landsat satellite programme, demonstrating the potential of satellite data in monitoring ecosystems and changes to them.
The "before and after" shots show vividly just how vast the changes have been, not only since the first Landsat satellite in 1972, but on much shorter timescales. Deforestation is shown not only as mass forest disappearance in countries such as Rwanda, but also as the insidious spread of logging roads through once entirely untouched rainforests in countries such as the Democratic Republic of the Congo, and the replacement of natural forest by bright green rubber and palm plantations in Cameroon.
Urban spread is illustrated not only by the dramatic expansion of the Senegalese capital Dakar over the past half century, from a small urban centre at the tip of the Cape Verde peninsula, to a metropolitan area with 2.5 million people spread over the entire peninsula, but by the rapid development of a small town like Bangassou in the Central Africa republic, now beginning to affect the nearby forest.
Shrinkage of mountain glaciers is shown only in the well-known case of Mount Kilimanjaro, but also in the disappearing glaciers in Uganda's Rwenzori mountains, which decreased by 50 per cent between 1987 and 2003. And to the well-known cases of the drying up of Lake Chad, and falling water levels in Lake Victoria, the atlas adds new cases of disappearing water bodies like the drying up of Lake Faguibine in Mali, as well as many examples of desertification, unsustainable large-scale irrigation and degraded coastal areas.
Put it all together and you have a picture that is hard to credit, so enormous is the destruction. Statistically, the atlas finds that deforestation is a major concern in no fewer than 35 African countries, including the Democratic Republic of the Congo, Rwanda, Nigeria and Malawi, among others. Africa is losing more than four million hectares of forest every year – twice the world's average deforestation rate.
That problem is closely followed in significance by major loss of biodiversity [wildlife] which is occurring in 34 countries, such as Angola, Ethiopia, Gabon and Mali. Land degradation is similarly a major worry for 32 countries, including Cameroon, Eritrea and Ghana, with some areas across the continent said to be losing more than 50 metric tonnes of soil per hectare per year.
The atlas shows that erosion, as well as chemical and physical damage, have degraded about 65 per cent of the continent's farmlands. In addition, slash-and-burn agriculture is adding to the number of wildfires which are naturally caused by Africa's high prevalence of lightning.
Rapidly rising populations account for one of the principal pressures on the natural resource base. Between 2000 and 2005, the atlas says, Africa's population grew by 2.32 per cent annually – nearly double the global rate of 1.24 per cent per year. Twenty of the 30 fastest growing countries in the world are in Africa, including Liberia, which has the highest annual growth rate – 4.8 per cent – of any country in the world. In the next half century Africa will have twice the population growth rate of any other region. This means that more and more land must be devoted to agriculture, but as the amount of available land is limited, the amount available per person is swiftly shrinking. The atlas points out that in 1950 there were 13.5 hectares of land per person in Africa, but by 1990 this had shrunk to 4.7 hectares per person and by 2005 to 3.2 hectares per person – while on present population growth estimates, by 2050 the amount will be 1.5 hectares per person.
And now, it says, climate change is emerging as a driving force behind many of these problems and is likely to intensify the "already dramatic transformations" taking place. Although Africa's 965 million people produce only 4 per cent of the world's total greenhouse gas emissions, they are likely to suffer disproportionately from the consequences of global warming, not least because African nations' ability to adapt to climate change is relatively low.
One of the key points the atlas makes is that environmental degradation is likely to have a higher human cost in Africa than in other regions, as people on the continent live in closer relation to the natural world than elsewhere: they are often directly dependent on the environment.
It was for African governments themselves to address the problem, said Marion Cheatle, chief of UNEP's Early Warning Branch, who introduced the atlas in London. "In many places you have a problem of policies being enforced. Not that policies and legislative instruments [to protect the African environment] are not in place, but very often they're only on paper, and they don't have the management to follow that really should be in place."