Tackling the global water crisis
In a specially-commissioned survey for UNEP's GEO-2000, 200 leading scientists from 50 countries around the world identified a shortage of clean water as one of the most pressing problems facing humanity.
Already 20% of the world's population lacks access to safe drinking water, while 50% lacks access to safe sanitation. This situation is set to worsen dramatically.
The World Meteorological Organization predicts that if there is no change to current consumption patterns, two out of three people will live in water-stressed conditions by the year 2025. In other words, water consumption will be running at an unsustainable level.
Perhaps inevitably, the problem is most acute in Africa and West Asia. In Africa, for example, 14 countries already experience water stress or water shortage. Another 11 countries will join that list in the next 25 years.
However the problem is a global one. Economic growth in territories such as China, India and Indonesia is constrained by the prevailing water conditions. Even in water-abundant North America, the growth of municipal and industrial demands for water has "led to conflicts over water rights" and is "a constraint to growth - especially in the west and southwest of the USA," says GEO-2000.
Clearly, part of the global water problem is increased usage of water for domestic, industrial and agricultural purposes - a direct response to the increased population. Agriculture alone accounts for 70% of water usage - mainly for crop irrigation. As the world's population grows, so irrigated land is expected to becoming increasingly significant in feeding people.
Water quality is also a major concern. Sewage in particular is a severe hazard. According to GEO-2000, "In many developing countries, rivers downstream of major cities are little cleaner than open sewers." Worldwide, polluted water is estimated to affect the health of about 1200 million people and contribute to the death of 15 million children under five every year.
Sewage is not the only cause of water pollution. Intensive use of pesticides and fertilisers has increased the level of nitrates in water. This can lead to brain damage and even death among children. Industrial waste is also a significant polluter - giving rise to contamination with heavy metals. In a study of 15 Japanese cities, it emerged that 30% of all groundwater supplies are contaminated by chlorinated solvents from industry. In some cases, solvents from spills travelled 10km from the source of pollution.
Water shortage increases social inequity. In regions such as Gujurat in India, where groundwater levels have dropped considerably, poor farmers cannot sink boreholes to the necessary depths to extract water. Wealthier farmers can benefit by moving inland to buy up more land.
In regions like Africa, uneven water distribution is clearly a problem. The Congo River basin contains 10% of Africa's population but 30% of the continent's run-off. The Niger Delta receives abundant rain while the neighbouring Sahara gets virtually none.
With an estimated 300 million people in Africa short of water, there is understandable concern about how to manage access to safe water. According to GEO-2000, 50 rivers in Africa are shared by two or more countries. "Access to water from any of these shared rivers could provoke conflict, particularly in the Nile, Niger, Volta and Zambezi."
An even more critical picture is emerging in West Asia (which centres on the Middle East). Here the pace of population growth far exceeds the development of water resources.
Without urgent water management, says GEO-2000, a major environmental problem will emerge - perhaps resulting in "escalating conflict over shared surface and groundwater resources if agreements are not reached on equitable allocations." With continued political tensions across the region, water management is a matter of some urgency for global policy-makers.
A fundamental theme to emerge from GEO-2000 is the need to understand linkages between major environmental problems. While "good water management can solve many of the problems of pollution and scarcity," it cannot be handled in isolation.
Clearly, large cities need to develop co-ordinated responses to sewage and industrial pollution while agriculture needs to minimise wastage. According to GEO-2000, "40-60% of Africa's irrigation water is lost through seepage and evaporation." Not only is this a waste of valuable resources, it also leads to problems like soil salinization and water-logging.
Likewise, the intensive use of fertilisers is responsible for introducing unhealthy levels of nitrates to the water supply. Effective control of nitrogen-based fertilisers could minimise water loss and have a beneficial impact on global warming.
GEO-2000 concludes that water management is "inextricably linked with land issues." A holistic approach requires: co-ordination of the management of land and water resources, establishment of secure land and water property rights where these do not exist, reorganization of policies at river basin level, introduction of concepts of shared and equitable water use and alternatives to use of marginal land.
What is not known is how far humanity's impact on the climate will exacerbate the water problem. GEO-2000 warns that "water managers are becoming increasingly concerned about the impact of climatic variability on water resources - including those associated with El Niño."
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