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A devastating drought gripped East Africa from 1980 to 1986. Although
it affected many nations, Ethiopia, Sudan and Mozambique were hardest hit.
Televised reports of the misery that afflicted the people of these countries
moved us all, and varied forms of aid made their way to the badly stricken
regions. In particular, the perception of the cause and effect of the situation
was as disturbing as the television images. Most commentators seemed to
believe that somehow the local inhabitants bore the responsibility for their
misfortune. Nomads and Bedouin of these parched lands were blamed for the
ruin of their own environment: their misuse of the land, by chopping down
trees for firewood and allowing their animals to overgraze the range, had
turned their land into a desert.

To those of us with longer memory, what happeend in East Africa was
not unique. About a decade earlier, misery and mass starvation afflicted
countries of the African Sahel, a belt of semiarid lands south of the Sahara
extending from Somalia in the east to Senegal in West Africa. Reporters
also blamed the Sahel drought on the advance of the desert through misuse
of land by local inhabitants. This repeated mistake has created one of the
most prevalent misconceptions of modern times: the notion that people make
deserts. This is typical of the naive tracing of all the ills of the Earth
to the actions of mankind. It implies that people living in drylands ruin
their environment because they do not understand it.

To charge the inhabitants of the drylands with ignorance of their environment
is to discount thousands of years of experience of learning how to live
in the desert. There are plenty of examples to illustrate that people who
carve a life in this harsh environment know far more than outsiders credit.

Deserts are defined as areas that receive less than 25 centimetres of
rain per year. They host only a limited and specially adapted population
of animals, and few plants. Cold deserts, near the Earth’s poles, are always
covered by snow and ice. Hot deserts make up about 20 per cent of the land
of the Earth in two belts between about 20 degrees and 30 degrees north
and south of the Equator. These are surrounded by semiarid belts, together
forming a third of the land area of the Earth, and home to nearly a billion
people.

Monique Mainguet, a geographer from the University of Rheims, France,
stood at the shores of Lake Chad and asked a Tibbu tribesman about the origin
of the sands around the lake. She did not expect a valid answer from the
simple man. So when the answer came, ‘my father used to say the sands came
from Egypt’, she discounted it in her mind. A decade later Mainguet and
I were to examine images of Africa taken from space. She was amazed to realise
that the sands of Lake Chad were connected through lines of dunes to the
Great Sand Sea in the Western Desert of Egypt, some 2,400 kilometres away.

The problem of stabilizing the massive dunes that move across sandy
deserts has puzzled many minds. The Uygur of Central Asia have developed
a simple and effective answer. Leaving the topography of dunes as shaped
by nature, they checkerboard their surfaces with squares of straw roughly
a metre across. The resulting fishnet pattern gently breaks the force of
the wind and restricts the movement of sand to within the squares, stopping
the drift of the dunes.

Like other inhabitants of drylands, Bedouin of the Arabian Desert have
become sensitive to their environment. They can establish their direction
and find their way even during dust storms when the sky as well as their
own feet disappear from view. ‘We could always find our way without a compass
and bow in the direction of Mecca for our prayers,’ explained an elder from
Kuwait. ‘We felt the stones on the ground. Their pitted surfaces always
faced north becuase this is in the direction from which the shemal wind
blows.’ Researchers have recognised this distinctive pattern, which comes
from attrition by sand grains carried in the prevailing wind, in desert
pebbles nowadays and in the geological record.

Over the millennia, the same Bedouin have also developed strict rules
for grazing. They have a vested interest in protecting the range because
they know that some day it may save their livelihood. The longest war fought
in Arabia began during the 5th century when one camel belonging to a particular
tribe strayed to graze in a range that was declared off limits for regeneration
by another tribe. Killing that camel initiated the Basus War, which lasted
for a total of 40 years.

The idea that people make drylands also assumes that outside experts
know the desert better than its local inhabitants, and it implies that because
‘ignorant natives’ made the desert, we can ‘fix it’ by applying modern science
and technology. Numerous aid projects intitiated by genuine concern and
subsidised for the purpose of ‘economic development’ fall into this trap.

Following the Sahel drought of 1968 to 1973, projects were initiated,
by the United Nations Environment Programme (UNEP), the World Bank and the
United States Agency for International Development, to drill deep wells
near towns in countries such as Mauritania. The result was the quadrupling
of the population of towns, particularly Nouakchott, because nomadic peoples
settled near the wells. The nomads and their herds lived in an area that
could not support their large numbers, and real degradation of the environment
began.

Not-so-expert-help

In some cases, problems arise from inappropriate practices. In desert
reclamation projects in the Dakhla Oasis, in the Western Desert of Egypt,
I often encountered rice fields. Rice is a crop that should never be raised
in such an area, because it needs 6,000 times its weight in water for a
successful harvest. Also, in a desert depression such as that of Dakhla,
used water cannot be drained out and stays in low areas to act as a breeding
ground for mosquitos and other pests. Overirrigation eventually destroys
the soil: because of the high evaporation rates, salinity increases after
each watering and soon the soil becomes encrusted with a layer of salt.
Similarly, Andrew encountered such blundering in his field excursions –
in the southern Sahara he came upon wheat fields. Like rice, wheat devours
the meagre supply of groundwater.

A more direct problem of degrading the environment arose in central
Africa. Photographs taken from space in 1975 showed an unusually bright
area near the northern shores of Lake Chad. The brightness signalled degradation
of the land because it suggested that the vegetation covering the surface
had gone, exposing sand that could drift away. The research team that went
to the scene to investigate found out that the degradation visible from
space was the result of the tracks of countless vehicles at a favourite
show place for representatives of international aid agencies.

Although dificult for those responsible to admit, in some cases much
of the damage to the environment results from projects conceived by ‘experts’.
The problems arise from a lack of understanding of how deserts form and
how they evolve in space and time. UNEP has announced that, in Africa alone,
the desert is eating up 62,000 square kilometres of fertile land each year
because of human activity. This would mean that the Sahara, encompassing
about nine million square kilometres of the driest land on Earth, would
double in size in 145 years – an impossible inference.

The Sahara, like other hot deserts of the Earth, formed because of the
scarcity or lack of rain. Dryness alternated with wet climate in cycles
throughout geological time. The deserts once received vast outpourings of
rain, form which sprung abundant vegetation; animals and people roamed the
land. When the climate changed and the land became dry, plants, animals
and humans gradually left.

The conditions that form deserts start with the patterns of air circulation
around the globe. Rainfall depends on a system that involves evaporation,
condensation, wind and ocean currents. The circulation begins around the
Equator, where there is more direct sunlight for longer periods each day
than at higher latitudes. In the heat of the Sun, the air picks up moisture
from ocean surfaces and rises, leaving behind regions of low pressure close
to the ground. Cooler and denser air rushes down to fill the gap. As the
warm air rises it loses moisture and forms clouds, which rain on the tropical
forests between 15 degrees north and south of the Equator. When the dry
cool air circulates back to the surface of the Earth it warms up and absorbs
any moisture around the tropics of Cancer and Capricorn, where the deserts
and simiarid lands of the world lie.

Ocean currents can also play a role in forming a desert. As the cool
water of these currents brushes against warm air, at the coast clouds of
fog envelop the area. Offshore winds hold the fog near the shore so that
little of this moisture reaches the land. This is the cause of the coastal
deserts of Peru and the Namib of southern Africa. In another mechanism,
mountain ranges can cast a rain shadow, resulting in, for example, the Patagonian
Desert of South America. As clouds rise over mountains, they cool and rain
or snow. Air that reaches the lee side of the range is dry, so little rain
falls. Furthermore, sheer distance from oceans can create arid regions,
such as the inland tracts of Central Asia, after moisture carried onshore
from the seas condenses and falls closer to the coasts.

If the amount of energy falling on the Earth never changed, the belts
of desert would stay in the same places. But the Sun rotates and its output
varies slightly. In addition, the distance from the Earth to the Sun varies,
and the Earth’s position in its orbit alters. When the planet receives the
most energy from the Sun, the air becomes warmer, more water evaporates
and the equatorial cloud belt expands: the deserts shrink. The converse
happens during years which bring less energy from the Sun, and the deserts
expand. A map of desert boundaries becomes out-of-date even in the year
it is completed. This role of the Sun in the waxing and waning of desert
conditions is emphasized in an old Indian saying: ‘From the Sun comes rain;
from the rain comes the forest, and hence, the people.’

The surface of the desert provides tangible geological, archeological
and biological evidence of shifts in climate in past times. In today’s deserts,
one encounters bones of animals and fragments of ostrich eggshells, as well
as hand tools, milling and grinding stones, and fragments of pots. Such
remains prove animals and humans lived there in the past.

French geologists have uncovered evidence that climatic changes in Africa
during the past 150,000 years are closely related to natural changes in
the Earth’s orbit about the Sun, variations in the volume of ice on the
globe, oceanic temperatures, and the resulting fluctuations in water and
air circulation. Major variations in atmospheric patterns resulted in great
variations in the latitudes of climate zones, especially the deserts. Thus,
the demarcation line of the Sahel moved 1,000 kilometres farther north between
18,000 and 8,000 years ago. On the other hand, the same line moved 600 kilometres
farther south between 6,000 years ago and the present.

According to Nicole Petit-Maire of the Laboratory of Quaternary Geology
in Marseilles, France: ‘These processes were not man-induced but wholly
natural.’ Her review of the findings indicated that neolithic groups lived
throughout the Sahara between 7,000 and 4,500 years ago around swamps and
lakes. But ‘they were scarce in number, did not raise cattle, and can by
no means be blamed for the deterioration of the biota.’

The aridity of the Sahara dates back to mid-Tertiary times, over 20
million years ago, and long before humans appeared on Earth. Most other
deserts show signs of dry climates dating back to five million years ago.
As a schoolboy in Egypt, I read that the region west of the Nile used to
be the ‘granary of the Roman Empire’, and became a desert because of misuse.
My own work contradicts this and proves that the desert has remained as
dry as it is today for 4,500 years, long before the Roman Empire came into
being. The ‘granary’ may have been the fertile land of the Nile River and
its Delta, but not the desert to the west.

This leads to the conclusion that the desert is not the fault of the
nomads and Bedouin, neither is it their fate. It is part of the natural
environment of the Earth. We should study drylands in this light in order
to utilise more of them for the benefit of mankind. From the outset, we
must understand how the deserts came into being and what their features
mean.

Thousands of years of erosion by running water during times of rainy
climate flattened most of the terrain. Working both physically and chemically,
the water dismantled mountains grain by grain, dug wide channels in the
plains, and deposited thick layers of sediment in low areas. During dry
climates, the wind takes over. It whirls the finest particles into the atmosphere
as dust. When the force of the wind increases, grains of sand start to bounce
along the ground and accumulate into dunes, which march across the deserts.
Their menace may be averted if we know where they are going, and how quickly.
Some dunes may even act as useful collectors of the scant rain water. For
days after an occasional burst, dune sand remains wet; nomads and Bedouin
seek it out to quench a desert thirst.

The answer to the cyclical droughts that scorch the land is not to settle
the nomads around overcrowded towns, where they are no longer fully able
to utilise their skills. Mankind must do better in the future to lessen
the impact of such devastating effects of droughts. Western societies have
learned how to deal with natural disasters such as floods, earthquakes,
and even volcanic eruptions. It is now the time to learn about the severe
arid environment.

The desert is not the enemy. No matter how harsh its environment seems,
it contains the seeds of survival. Rain in the geologic past left behind
a vast acreage of potentially arable land. And some of that rain water seeped
through the rock to be stored in giant underground aquifers. Many have been
found in numerous deserts, and I think that much more groundwater is yet
to be discovered, particularly through images of the Earth from space.

In November 1981 NASA’s space shuttle collected a strip of radar images
of the terrain beneath the sands in the southern reaches of the Western
Desert of Egypt. In an area that is now bone-dry, the radar waves penetrated
5 metres of sand to unveil ancient river courses 8, 12 and 20 kilometres
across. Based on this, the Egyptian General Petroleum Corporation selected
a region to explore for groundwater. Eleven wells were drilled and all brought
fresh water from depths between 10 and 100 metres. A 5,000-acre experimental
farm is now functioning as the precursor of a vast agricultural settlement.
The groundwater resources now prove are capable of supporting agriculture
over 200,000 acres for 200 years.

While we use space technology to search for resources in the deserts,
we should not neglect the way of life of the nomads. Attempts should be
made to reinstate some of their age-old practices and wisdom. Nomads and
Bedouin roam the land, followed by their herds, not because they are restless,
but because this is the only way to use their scarce water resources. In
the desert, when it rains it does so in one small area and not in others.
And when the occasional rain clouds return, rains fall somewhere else. Desert
dwellers have developed a remarkable sensitivity to such happenings from
thousands of years of experience of living in an arid environment.

In addition, we should accept that the desert climate follows cycles.
From records of Nile floods during the past 2,000 years, Joseph Fletcher
of the National Oceanic and Atmospheric Administration in Boulder, Colorado,
has established one cycle lasting 135 years. The cycle that people are most
aware of is the one mentioned in the Bible. Egypt’s pharaoh dreamed of seven
ears of grain, fat and healthy, growing on a single stalk. Behind them sprouted
seven ears of grain, shrivelled and thin and blasted by the east wind. Joseph
interpreted the dream as seven years of plenty followed by seven years of
famine.

The moral of this biblical story is as applicable today as it was then.
Part of the harvest in years of abundance should be stored for the lean
years. Furthermore, surface water (found in rivers, lakes and as rain) should
be used during wet climatic episodes. Groundwater resources should be saved
for use during years of drought. Let us not forget that the Sahel drought
of 1968-1973 was followed by six years of rain, until another cycle of drought
began in 1980. Today the situation in the semiarid lands south of the Sahara
has again improved. But undoubtedly another cycle of drought will prevail
in a few years’ time.

Today’s hot scientific debate is whether or not the temperature of the
Earth is increasing due to the ‘greenhouse effect’. As we ponder the potential
effects of the increase of gases such as carbon dioxide, methane and chlorofluorocarbons,
we must also learn how to adjust to the changes that may come before we
can do anything about their causes. People who have lived under regularly
changing climatic conditions could teach us a thing or two. Rather than
attempting to aid them by projects of questionable value, we should study
how they have adjusted to climatic fluctuations in the past. Only then would
we be able to usher sustainable development into the drylands of the Earth.

Farouk El-Baz is Director of the Center for Remote Sensing at Boston
University, and President of the Arab Society for Desert Research.