The world population, now 6.1 billion, has already doubled since 1960 and is projected to grow by half, to 9.3 billion, by 2050. Some two billion people already lack food security, and water supplies and agricultural lands are under increasing pressure. Water use has risen six-fold over the past 70 years and by 2050, 4.2 billion people will be living in countries that cannot meet people’s daily basic needs using more resources with more intensity and leaving a bigger “footprint” on the earth than ever before. In addition, unclean water and poor sanitation kill over 12 million people each year, while air pollution kills nearly three million, concludes the new report by the United Nations Population Fund (UNFPA), Footprints and Milestones: Population and Environmental Change.

Global poverty cannot be alleviated without reversing the environmental damage caused by both rising affluence and consumption and by growing populations, the report stresses. Empowering women and enabling them to have only the number of children they want would lead to smaller families and slower population growth, easing pressure on the environment, it says (see related story). The world’s richest countries, with 20% of global population, account for 86% of private consumption while the poorest 20% account for just 1.3%, while a child born today in an industrialised country will add more to consumption and pollution over his or her lifetime than 30 to 50 children born in developing countries.

One of the major themes of the report is the link between population growth and supply and quality of water supplies. Global population has tripled over the past 70 years and water use has grown six-fold as the result of industrial development and increased use of irrigation. However, more recently, per capita use of water has levelled off, so total water consumption is growing at about the same pace as population. Satisfying the water needs of 77 million additional people each year has been estimated as requiring an amount roughly equal to the flow of the Rhine. While, worldwide, 54% of the annual available fresh water is being used, if consumption per person remains steady, by 2025 we could be using 70% of the total because of population growth alone. However, if per capita consumption everywhere reached the level of more developed countries we could be using 90% of the available water by 2025.

In the year 2000, 508 million people lived in 31 water-stressed or -scarce countries, but by 2025, three billion people will be living in 48 such countries, the UN says. The number of people living in conditions of scarcity will double, and those living in water stress will increase six-fold. An even better measure of water stress is river basins, says the report. Currently 2.3 billion people live in river basins that are at least water stressed, while 1.7 billion live in basins where scarcity conditions prevail, but by 2025 these numbers will be 3.5 billion and 2.4 billion, respectively.

The figures given in the report assume no change in the efficiency of water use and it has been estimated that relatively low-cost technologies could double agricultural productivity per unit of available water. In the past 50 years, industrialised countries have significantly increased efficiencies in industrial and agricultural water use. While many of the same technologies, such as using drip irrigation instead of flood irrigation, are increasingly available in developing countries, cost and cultural issues, like educational outreach to facilitate behaviour change, must be addressed.

On water quality, the report notes that the World Health Organization has found that some 1.1 billion people do not have access to any clean water, while 2.4-3.0 billion lack access to sanitation. These shortcomings are most pronounced in rural areas, where 29% of residents lack access to clean water and 62% to sanitation systems, but rapid and unplanned population growth in and around urban areas is overwhelming their capacity to meet water needs, and for the first time, official statistics reflect a decline in coverage compared to previous estimates. Overall, estimates are that clean water is not available to at least 6% of urban dwellers and 14% lack sanitation. However, in developing countries, 90-95% of sewage and 70% of industrial wastes are dumped untreated into surface waters. With increased population pressure on cities, the ability of natural systems to purify circulating water lessens while quality decreases.

The report notes that the construction of large dams has slowed, particularly in more-developed countries, as appreciation of their disadvantages grows, it says. These include environmental disruption, displacement of long-settled populations, loss of agricultural land, silting and denial of water to downstream areas. However, large dam projects are still planned in Turkey (see this week’s ‘Europe’ section), China (see related story) and India.

On land use, the report says that to accommodate the nearly eight billion people expected on earth by 2025 and improve their diets, the world will have to double food production. However, moderate to severe soil degradation affects nearly two billion hectares of crop and grazing land, an area larger than the United States and Mexico combined. Soil erosion and other forms of land degradation claim five to seven million hectares of farmland each year and the phenomenon threatens the livelihoods of at least one billion farmers and ranchers, most of them in poor countries, the report says. In Kazakhstan, for instance, the Institute of Soil Management has estimated that the country will lose nearly half of its crop-land by 2025 due to soil erosion and degradation.

The UNFPA looks forward to next year’s Johannesburg 2002 review of the 1992 Earth Summit agreement to present an opportunity to incorporate an “integrated social agenda – including education for all and universal access to reproductive health care and family planning – into initiatives to promote sustainable development”.

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