The UK's reliance on 'virtual' water, in imported food and other supplies, is exacerbating water shortages in other countries, engineering experts report. They warn the UK's future development could be threatened if we do not address the escalating global water crisis with urgency.
In a new report the Engineering the Future alliance* warns that with population growth, urbanisation, changing diets, pollution of water resources and climate change, global water resources are set to become even more stressed. Two thirds of the UK's water footprint is now effectively imported in the form of food, energy and other goods, that require water for production and transportation from countries that are themselves under water stress.
Water is one of the most undervalued natural commodities in the world, directly affecting national security through its impact on economic growth, energy security, food supply and healthcare. This domino effect has been described by the Government's Chief Scientific Advisor Professor John Beddington as a 'perfect storm', which could lead to global instability if each of the inter-dependent elements are not addressed.
Chairman of the working group Peter Guthrie, Professor of Engineering for Sustainable Development here at the Department, says:
"If the water crisis becomes critical it will pose a serious threat to the UK's future development because of the impact it would have on our access to vital resources. Food prices would sky-rocket and economic growth would suffer.
"To prevent this we must recognise how the UK's water footprint is impacting on global water scarcity. We should ask whether it is right to import green beans - or even roses - from a water-stressed region like Kenya, for example. The burgeoning demand from developed countries is putting severe pressure on areas that are already short of water. Our virtual water footprint is critical and we need to give it far more attention."
Global Water Security: an engineering perspective says that the UK must take the lead by tackling its own water footprint, managing its own water resources sustainably but also by managing the virtual water embedded in its imports. Because the UK uses so much water internationally through its imported goods and services, it has a duty to provide providing leadership on the development and implementation of global responses.
Engineering the Future identified several areas where action will aid the global response to water security:
1. Water management solutions should be considered in the context of the entire water system, from "cloud to coast" as well as the implications immediately upstream and downstream. In this systems approach, all types of water must be considered together, and in this context, the flows and uses of water in a catchment area feeding the soil (green water), free water in rivers and reservoirs(blue water) and used or waste water (grey water) all need to be included. This approach can lead to significant efficiencies in managing water system.
2. New and better technologies and practises. Technologies and techniques already exist but they need to be refined, developed and in some cases re-assessed in relation to the energy-food-water nexus and to take into account the impact on the eco-system. Key will be finding ways to improve water efficiency in agriculture, which makes up 70% of current water usage and is vital for food supply. As our diets are changing to include more meat than grains, this is expected to increase significantly. One kilogram of beef requires ten times the amount of water that grain does to produce and transport (see facts list below).
3. Developing new, sustainable sources of water through technology. Current methods include desalination, water recycling, reuse and harvesting however these do not take the energy-food-water nexus into account. Global Water Intelligence recently reported an extra 9.5 cubic metres of freshwater is being produced per day, mainly due to a marked increase in water desalination. Engineering the Future warns that desalination is currently extremely energy intensive and unless low carbon energy sources can be used it is not a sustainable solution. Further research is required to find sustainable solutions.
4. Governance and regulation. Water security transcends geographical boundaries and requires international regulation to ensure localised responses do not adversely impact elsewhere in the water system. Local responses can be tailored to meet specific requirements within this global framework.
Professor Guthrie concludes: "There is no single silver bullet for water security. Water management must be looked at in a holistic way, from 'cloud to coast' including all forms of water - in the soil as well as in rivers and reservoirs. Reducing demand will be important but so will developing engineering solutions to create new, sustainable sources of water and promote efficiency in current practices.
"This is a complex issue that transcends geographical and cultural boundaries and cuts across many other crucial sectors such as energy and food supply. To avoid the perfect storm requires a global response, with global policies and governance - backed up by forward-thinking action at a national level to meet individual countries' requirements."
* An alliance including the Institution of Civil Engineers (ICE), Royal Academy of Engineering (RAE), and the Chartered Institution of Water and Environmental Management
Download the report at www.raeng.org.uk/gws
Water facts and figures
It is estimated that globally more than 1.2 billion do not have safe drinking water, 2.4 billion lack sanitation facilities, and 1,000 children die every day as a consequence of waterborne diseases.
One kilogram of beef requires 15,500 litres of water to produce, more than ten times the amount required to produce one kilogram of wheat. A t-shirt requires 2,700 litres of water to produce.
Professor John Beddington's 'perfect storm' scenario says that by 2030 we will need 50% more food, 50% more energy and 30% more water to meet demand. Download the report here http://www.bis.gov.uk/assets/biscore/goscience/docs/p/perfect-storm-paper.pdf
A March 2010 report by World Bank's Independent Evaluation Group found that the effects of water shortages are felt strongly by 700 Million people in 43 countries.
Water stress equates to an annual supply below 1700m3 per person.
Global population growth is estimated to increase from 6.8 billion today to 8 billion by 2025