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News Water security and climate change: Facts and figures

Freshwater is a scarce resource. Only 2.5 per cent of the 1.4 billion km3 of water on Earth is freshwater fit for human consumption, and most of this is inaccessible — nearly 70 per cent is locked up in glaciers, snow and ice. Our greatest source of freshwater is the 8 million km3 of groundwater, with only 0.3 per cent of freshwater (105,000 km3) being found in rivers, streams and lakes. 

Discussions about freshwater availability increasingly focus on water security, which refers to people's access to enough safe and affordable water to satisfy their needs for household use, food production and livelihoods. 

Water insecurity can arise from physical scarcity, resulting either from climatic or geographical factors, or from unsustainable consumption or overexploitation. It can also have economic origins, with poor infrastructure or capacity preventing access to the water resources available, or occur where pollution or natural contamination renders water resources inaccessible.

Water insecurity and scarcity already affect large parts of the developing world. The past century has seen a sixfold increase in global water demand. Nearly three billion people (about 40 per cent of the global population) live in areas where demand outstrips supply.

This situation is set to worsen in the coming decades as populations grow, economies develop and agriculture and industry expand.

Despite the problems, some policy priorities remain clear if developing countries are to cope with water insecurity in a changing climate.

The first is the need to prioritise the management of water resources. This may seem obvious, but many countries have no long-term water policies. Policies will need to integrate all the sectors that rely on water, from agriculture and fisheries to manufacturing and municipal water use.

Improving watershed and resource management is also vital. The IPCC has advocated integrated water-resources management as a framework for adapting to climate change across socioeconomic, environmental and administrative systems.

Involving local stakeholders and promoting community-based approaches is essential to ensure that adaptation options are taken up and achieve long-lasting results. This requires a better understanding of water-based livelihoods in the developing world and their vulnerability to climate-related hazards and the impacts of water security on food and livelihood security.

Addressing gaps in our knowledge about climate change and water is also a priority. Field data are sparse and, in many cases, observational networks are shrinking. The IPCC has highlighted the "need to improve understanding and modelling of climate changes related to the hydrological cycle at scales relevant to decision-making". It also says that information about the water-related impacts of climate change is inadequate.

Without further investment in data collection and knowledge building, the uncertainty associated with predicted changes will remain high, and estimates of hydrological change will remain inaccurate. Until we can better predict the change, we will be poorly equipped to plan for the future.

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Water security and climate change: how science can help, by David Dickson, Director, SciDev.Net. (15 September 2010)

Contact information Lucinda Mileham
News type Inbrief
File link http://www.scidev.net/en/agriculture-and-environment/water-security-climate-change/features/water-security-and-climate-change-facts-and-figures-1.html
Source of information Scidev
Keyword(s) Water security, climate change
Subject(s) AGRICULTURE , HYDRAULICS - HYDROLOGY , INFORMATION - COMPUTER SCIENCES , METHTODOLOGY - STATISTICS - DECISION AID , NATURAL MEDIUM , POLICY-WATER POLICY AND WATER MANAGEMENT , PREVENTION AND NUISANCES POLLUTION , RISKS AND CLIMATOLOGY , WATER DEMAND
Relation http://www.scidev.net/en/agriculture-and-environment/water-security-climate-change/editorials/water-security-and-climate-change-how-science-can-help.html
Geographical coverage n/a
News date 01/10/2010
Working language(s) RHAETO-ROMANCE
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