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greenhouse) and solar thermal technologies. The tech-
nological combination in the Sahara Forest Project is
hence designed to utilize what we have enough of to
produce what we need more of, using deserts, salt water
and carbon dioxide to produce food, water and energy.
The Sahara Forest Project proposes to establish a
range of interconnected economic activities in differ-
ent low-lying desert areas based around a pipeline that
creates an infrastructure for seawater to be brought
inland. The seawater is used to condition the desert air
in a greenhouse to create ideal growing conditions for
the crops inside. The evaporation cools the dry desert
air significantly, and the high humidity of the air inside
the greenhouse reduces the need for freshwater for irri-
gating the high-value plants grown inside. Some of the
water vapour in the greenhouse will condense on cold
surfaces such as the roof at night to provide the neces-
sary freshwater for the crop.
A flow of water vapour from the greenhouses will
add moisture to the surrounding environment. This
moisture has proven to have considerable potential for
aiding revegetation of the surrounding environment
outside the greenhouses. The salt water will also be
evaporated over outside structures ‘hedges’ so that a
considerable area will be provided with sheltered and
humid conditions. Further, the seawater infrastructure,
solar thermal installations and evaporative structures
can provide salt water, power and brine-handling for
For areas already severely affected by desertification there is a
need to implement restorative practices to bring back natural vegeta-
tion. The Sahara Forest Project is an attempt to realize such practices
through revegetation and the creation of green jobs through prof-
itable production of food, water and energy in desert areas. The
concept is known as restorative growth and has gained considerable
scientific and political support in recent years.
From vision to technology
Considerable parts of what are now considered desert areas were
formerly vegetated. The army of Julius Caesar conquered much
of the African territory north of the Sahara, turning forests into
farmland. For some 200 years North Africa supplied around two
thirds of Rome’s total grain supply. This resulted in deforestation,
increased salinity in the soil and loss of minerals. Around 250 AD
St Cyprian, Bishop of Carthage, wrote that the “world has grown
old and does not remain in its former vigour. It bears witness to its
own decline. The rainfall and the sun’s warmth are both diminish-
ing; the metals are nearly exhausted; the husbandman is failing in
his fields. Springs which once gushed forth liberally…now barely
give a trickle of water.”
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In the same way as an extractive use of resources has contributed
to loss of natural vegetation, the Sahara Forest Project proposes the
use of restorative practices to establish vegetation in arid areas and
reverse the trend of desertification. The ambitious target of restora-
tive growth will be achieved through a combination of existing and
proven environmental technologies, such as evaporation of seawater
to create cooling and distilled freshwater (i.e. in a saltwater-based
By establishing a seawater infrastructure it is possible to construct a value-chain in the desert
Image: The Sahara Forest Project