Water : Factfile

There are 16 documents in this section.

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  • Supply

    26 March 2008

    Around 75 per cent of the planet consists of water. 97.5 per cent of this water is contained in the oceans, hence salty and unsuitable for drinking or irrigation. Of the 2.5 per cent that is freshwater, just one-hundredth of one per cent (0.01 per cent) of the world's total supply - amounting to some 14 billion cubic metres - is considered easily accessible for human use on a regular basis. This water is found in rivers, streams, lakes and shallow aquifers. Much of the rest is tied up in inaccessible ice fields and glaciers.

  • Water shortages

    26 March 2008

    Despite a slowdown in population growth rates and family levels in many countries, the world's population is still growing by some 78 million per year. Finite water resources are coming under increasing pressure from population growth and over-use. This number implies an increased demand for freshwater of about 64 billion cubic metres a year - an amount equivalent to the entire annual flow rate of the Rhine River.

  • Water pollution

    26 March 2008

    Not only is freshwater water being over-used and wasted, it is also increasingly polluted. Each year roughly 450 cubic kilometres of waste water are discharged into rivers, streams and lakes. To dilute and transport this dirty water before it can be used again, another 6,000 cubic kilometres of clean water are needed - an amount equal to about two-thirds of the world's total annual useable freshwater runoff. If current trends were to continue, the world's entire stable river flow would be needed just for pollutant transport and dilution by the middle of this century.

  • Conflict over water

    26 March 2008

    Some commentators believe the imperative to share water across national borders could be a force for co-operation and peace. Others feat that conflicts over water - both political and violent - could erupt in coming decades as more countries, with ever larger populations, face water stress or scarcity. Dr. Peter Gleick, President of the Pacific Institute for Studies in Development, Environment and Security, puts it bluntly: the potential for conflict "is symptomatic of our inability in general to managed limited supplies of freshwater on a sustainable basis."

  • Irrigation

    26 March 2008

    On a global basis, agriculture accounts for 70 per cent of all annual water withdrawals. (In developing countries water consumption for agriculture is typically 70-80 per cent of total water consumption). The overwhelming bulk of this water is used for irrigated agriculture; only a tiny amount is accounted for by livestock. Some 40 per cent of the global harvest comes from the 17 per cent of cropland that is under irrigation.

  • Groundwater depletion and pollution

    26 March 2008

    About 2 billion people, approximately one-third of the world's population, depend on groundwater supplies, withdrawing about 20 per cent of global water (600-700 km3) annually - much of it from shallow aquifers.

  • Health and freshwater

    26 March 2008

    Of the 6.7 billion people on earth today, about 1.2 billion people lack access to potable freshwater and 2.6 billion do not have access to adequate sanitation facilities.

  • Wetlands shrinking

    26 March 2008

    Wetlands capture and retain rainfall, and prevent valuable sediments from being washed into lakes and rivers. They add moisture to the atmosphere, which falls as rain and cools the environment. Despite their value to humanity, half the world's wetlands have been lost, with most of the destruction taking place over the past 50 years. Since these fecund areas harbour a wealth of wildlife, their loss has contributed directly to the erosion of biodiversity and species loss.

  • Droughts and floods

    26 March 2008

    Over the past decade, the number of droughts and floods have increased dramatically, as environmental conditions have deteriorated and the global climate continues to change due to accelerated greenhouse gas emissions. According to the World Meteorological Organisation (WMO), the number of people affected by floods alone from 1991 to 2000 is reported to be around 1.5 billion.

  • Lakes in danger

    26 March 2008

    More than half of the world's five million lakes are degraded from human activities. The main threats include over-fishing, pollution, introduced species and habitat degradation from population growth, expansion of cities and impacts from industrial and agricultural activities.

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