Deserts Present Deep Challenges For Sustainable Development, But Also Great Opportunities
Aside from the direct effects of reduced vegetation cover from overgrazing and deforestation, the problem of human-induced land degradation and desertification does not appear to be as serious an issue in most true deserts as it is in many semi-arid and sub-humid regions. Deserts are less susceptible to land degradation, firstly because their biological productivity is very low, and secondly because vast desert areas are almost devoid of human interference and are thus safe from human impact. When the problem is present, it tends to concentrate on the deserts’ edge or on the more humid parts inside the biome, such as oases, and desert mountain sky-islands.
In these more vulnerable portions of the global deserts, however, impacts can be significant. Removal of vegetation cover, especially due to grazing, increases soil loss. Disturbance to the fragile desert surface, by military and recreational activities, leaves long-lasting damages. Mining activities and the remnants of these have contaminated freshwater bodies with high concentrations of heavy metals and chemical substances, as seen in parts of Argentina and Chile. Oil extraction causes air pollution, spills and chronic leakages that affect both surface and subsurface organisms. Irrigated portions of deserts in China, India, and Pakistan face declining yields due to increasing salinity. In China, deterioration of the plant cover in the headwaters region of the Yangtze River has created major flooding problems downstream and massive water erosion in the Loess Plateau. While biodiversity hotspots — the biologically-richest and most endangered terrestrial ecoregions — occupy 12 per cent of deserts, almost exactly the same proportion as for hotspots globally, the proportion of the desert biome with IUCN protected area status is much less (5.5 per cent) than the same figure for all ecoregions (9.9 per cent).
People have responded to these problems by developing and implementing actions at the regional and national levels. For example, in many countries in North Africa, as well as Yemen, there is a wealth of traditional knowledge on soil and water conservation in deserts through sustainable land management practices, including the retention of suspended sediments in terraces. In an effort to make better use of investments in water-control structures, a series of protective measures have been implemented in watersheds in Tunisia and Morocco. The application of newer technologies and practices for improved fallow periods, micro-basins, windbreaks, and soil bunds has gained global momentum in light of participatory approaches to soil conservation. Since the introduction of its National Soil Conservation Program in 1983, Australia has substantially expanded and improved its soil and water conservation technologies on private and public lands.
At the international level, several assessment efforts have included the desert ecoregions; among them, the Global Assessment of the Status of Human-Induced Soil Degradation (GLASOD) conducted by the International Soil Reference Information Centre in 1988; UNEP’s World Atlas of Desertification published by UNEP in 1992 and 1997; the chapter on drylands in the recent Millennium Ecosystem Assessment; and the currently on-going LADA (Land Degradation Assessment in Drylands) that started in 2006, under the auspices of several United Nations agencies. The Ramsar Convention has played a strategic role in the protection of oases and other desert wetlands. In 1994, UNCCD (the UN Convention to Combat Desertification in those Countries Experiencing Serious Drought and/or Desertification, particularly in Africa) was adopted by the international community, and 191 countries worldwide have signed or ratified the Convention so far. However, the Convention is mostly oriented towards sub-humid, semi-arid, and arid ecosystems, that is, the desert edges, and excludes the hyper-arid deserts of the world. Currently, there is no global or regional response strategy focused exclusively on deserts.
There are several forces behind environmental changes in deserts, which are also challenges to future development: changes in population dynamics will mainly affect rural desert communities along the great desert rivers. Large population increases are expected in resource-intensive populations of deserts in the United States and in the United Arab Emirates. These population changes will affect the quantities of water and energy consumed and waste produced in the desert biome. Inward investment was the strongest driver of change in deserts in the recent past; most went to the extraction of oil, gas, and minerals. Developments for nuclear weapons testing, nuclear waste, space flight, parking lots for unused aeroplanes, and other activities that have treated deserts as barren wastelands, all affect the desert environment. Tourism, another driver of change, brings nine million visitors to Morocco and Tunisia every year; there was a three-fold increase in tourism in Egypt in 2005, and Dubai claims to be the world’s fastest-growing tourist destination.
Global climate change and its impact on water regimes is already a driver of change in deserts. While rising energy prices will bring higher incomes to some oil-producing desert countries, others without this resource will suffer, as the costs of energy and water are closely correlated in deserts. Security issues from northern Africa to Iran have made deserts less accessible and have changed environmental and socio-economic conditions in these regions. Environmental problems caused by past, non-sustainable development pose enormous challenges. By far the best-known case has been that of the Aral Sea basin where the existing recovery programme will only save part of the former sea, and reduce only a proportion of the dust that the now-dry basin emits.
While building more dams and drilling for more groundwater are still tempting to policy-makers, the water in rivers that cross deserts is already thoroughly utilized, if not over-used. Groundwater, often extracted in excess of meagre recharge, rates currently provides 60–100 per cent of freshwater needs in most deserts lacking a large river. Given the escalating water crisis in many deserts, better water-use policy is urgent. Water supply can only be improved by combining new technologies with traditional water-efficient management. Useful technologies that can play an important role in future water supply include: drip irrigation and micro-sprinklers; desalination of brackish water, rather than saline water, to reduce the cost per cubic metre of treated water; fog harvesting in coastal deserts; and small sediment-holding dams and terraces.
Tourism is another opportunity for development, as long as the risks and dangers associated with it, such as volatility in the face of political conditions, competition for water and other resources, damaged beauty and biological value, temptation for street and organized-crime, social inequity, and litter, are recognized explicitly in policy. Deserts have much to offer for ecotourism, the fastest growing sector of the tourism market, although there are concerns that the label may be used to cover activities that damage ecosystems, such as off-road motoring.
Only a very small fraction of the solar power potential in deserts has been harnessed, and with the decline in the production of fossil fuel as well as technological improvements, solar sources might supply a significant portion of global energy by 2050. Wind and solar energy installations can make use of the cheap space, large inputs of solar energy, availability of some windy sites, and the absence of objectors in deserts. However, lengthy power connections required from remote desert locations are a disadvantage in both solar and wind energy production in deserts.