Space-consuming installations may still bring investment, although decisions are usually taken by national governments, whose fixations with national prestige or perceived vulnerability usually blind them to the interests of desert people or environments. Many large desert voids remain, far from habitation, and contain nothing to interest tourists. Many are remarkably resilient, especially those occupied by sand dunes. Desert dwellers and tourists will undoubtedly raise objections, nonetheless, on the grounds of competition for water, safety, pollution and aesthetics, if not of peace.

Wind and solar energy installations can also make use of cheap space, large inputs of solar energy, some windy sites and the absence of objectors (Box 5.4). Small solar cells, for domestic use and telecommunications, are now quite common in deserts, but only a very small fraction of the touted potential has been harnessed. The best-case scenario would have the deserts becoming the globe's principal suppliers of energy - forgetting for the moment the environmental costs and the destruction of beauty. Against this will be the length of transmission lines and competition from other renewable sources nearer to large centres of population. At the least, it can be confidently predicted that the adoption rate of small solar and wind energy devices will accelerate, especially if the obstacles are overcome: high capital costs; expensive, short-life batteries; inadequate facilities for repair and maintenance.

Agriculture and horticulture are already profitable in many deserts, as in Israel and Tunisia, and have great further potential. If there is water, or better, re-used water, and if it is used effectively, as in greenhouses, or by drip irrigation, the intense solar radiation and seasonal patterns of low-latitude deserts allow them to produce when higher latitude agriculture is not productive. Aquaculture can also flourish (Box 5.5.). Another resource is wild (and newly domesticated) desert plants (Box 5.6).