One billion city dwellers may face water shortages by 2050, study says

By 2050, more than 1 billion city dwellers may face water shortages if no new infrastructure is built or no new water conservation efforts are undertaken, according to a new study [1]. More than 3 billion may suffer similar water shortages at least one month of every year, says the study. The shortages are projected to hit megacities ranging from Beijing to Delhi, Mexico City, Lagos and Tehran.

The study looks only at water availability within a metropolitan region. Many more people lack access to clean water if problems of inadequate water quality or delivery within cities are taken into account.

To define “water shortage,” the study used a standard of 100 litres per person per day, which the World Health Organization says is the minimum a person needs for “optimum” long-term health and sanitation.

The researchers found that urban population growth will account for most of the big projected increases in water shortage. Climate change may add an additional 100 million more people to live without adequate supplies unless cities take measures on time.

Common infrastructural solutions to address water shortages such as transporting water longer distances, building dams and desalination are all expensive. Better ways to address shortages, says one of the study’s authors Rob McDonaldOne solution, are more efficient water use by agriculture and industry, payments to farmers to reduce areas of irrigated agriculture, and removal of non-native water-hungry vegetation such as eucalyptus.

“The thing I’m really worried about,” says McDonald, “is how the poorest cities are going to be able to afford to get water to their residents. Right now, many poor cities have trouble delivering clean water to their residents, and unless new capital is available for investment the situation will get worse.

“There’s a real shortfall in investment right now in solving this problem, and the developed countries in my opinion need to play a larger role in helping close that shortfall.”

[1] McDonald, R.I. … [et al.] (2011). Urban growth, climate change, and freshwater availability. PNAS, Published online before print 28 March 2011. DOI: 10.1073/pnas.1011615108 [open access]

Source: Robert Lalasz, Cool Green Science, 28 Mar 2011

Climate change: a scapegoat for the world’s water woes?

Climate change and adaptation [was] a central topic of the 5th World Water Forum (WWF) in Istanbul.

[...] Is the overwhelming emphasis on water and climate change justified? Certainly water is predicted to be the primary medium through which early climate change impacts will be felt by people, ecosystems and economies. Both observational records and climate projections provide strong evidence that freshwater resources are vulnerable, and have the potential to be strongly affected. However, the recent IPCC Technical Report on climate change and water recognises impacts on water have yet to be adequately addressed in either scientific analyses or water policy – an issue that [was] discussed at a meeting hosted by the Overseas Development Institute (ODI) in [the  UK]  Parliament on 30 March [2009].  

But nagging questions remain. How do we separate out the impacts of climate change from those related to socio-economic and demographic trends, and should we  deal with adaptation as a separate development issue? Separating impacts and responses is not easy, but it is clear that climate change is one of a number of pressures on water and livelihoods.

Take demographic change in sub-Saharan Africa. In contrast to the lack of knowledge on the direction and magnitude of hydrological changes under different climate change scenarios, the prospects of demographic change in the 21st century are known with some certainty. The population there  is expected to increase from 700 million in 2007 to 1100 million in 2030 and 1500 million by 2050, and populations will become increasingly urban. Overall water demand can therefore be expected to more than double in the first half of the 21st century, without considering rises in per capita demand for food and water. In Ethiopia, the figures are particularly alarming. The population is expected to increase from 77 million in 2007 to around 146 million by 2050, an increase of almost 90 per cent         

What are the implications for development, and for adaptation? There are perhaps two main conclusions. Firstly, treating development and adaptation as separate issues is misguided. In Ethiopia, extending access to secure water and sanitation, and reducing dependence on unprotected water sources, is central to both poverty reduction and adaptation. This is simply ‘good development in a hostile climate’, in a context where access to water rather than its absolute availability will remain key.

Yet despite all the calls for adaptation ‘mainstreaming’ – in Istanbul it [was] treated as a separate subject; other sessions in different halls focussed on water management, water supply and sanitation, irrigation and disaster management. Second, a sense of perspective is needed. There is a real danger that climate change is crowding out other, inter-related concerns around demographic shifts, urbanisation, water pollution and changing land use. There are multiple pressures on water. Climate change is one of them.

Source: Roger Calow, ODI blog, 20 Mar 2009

Water shortages: a growing problem, but not for the reasons most people think

THE overthrow of Madagascar’s president in mid-March was partly caused by water problems-in South Korea. Worried by the difficulties of increasing food supplies in its water-stressed homeland, Daewoo, a South Korean conglomerate, signed a deal to lease no less than half Madagascar’s arable land to grow grain for South Koreans. Widespread anger at the terms of the deal (the island’s people would have received practically nothing) contributed to the president’s unpopularity. One of the new leader’s first acts was to scrap the agreement.

[...] Local water shortages are multiplying. Australia has suffered a decade-long drought. Brazil and South Africa, which depend on hydroelectric power, have suffered repeated brownouts because there is not enough water to drive the turbines properly. So much has been pumped out of the rivers that feed the Aral Sea in Central Asia that it collapsed in the 1980s and has barely begun to recover.

[...] Two global trends have added to the pressure on water. Both are likely to accelerate over coming decades. The first is demography [and] the other long-term trend affecting water is climate change.

[...] Not surprisingly, investment in water has been patchy and neglected. Aid to developing countries for water was flat in real terms between 1990 and 2005. Within that period, there was a big shift from irrigation to drinking water and sanitation-understandable no doubt, but this meant less aid was going to the main users of water, farmers in poor countries. Aid for irrigation projects in 2002-05 was less than half what it had been in 1978-81. Angel Gurría, the head of the Organisation for Economic Co-operation and Development, talks of “a crisis in water financing”.

As is often the way, business is ahead of governments in getting to grips with waste. Big drinks companies such as Coca Cola have set themselves targets to reduce the amount of water they use in making their products (in Coke’s case, by 20% by 2012). The Nature Conservancy, an ecologically-minded NGO, is working on a certification plan which aims to give companies and businesses seals of approval (a bit like the Fairtrade symbol) according to how efficiently they use water. The plan is supposed to get going in 2010. That sort of thing is a good start, but just one step in a long process that has barely begun.

Read more: Economist, 09 Apr 2009

Global Trends 2025: mounting pressure on energy, food, and water

“The drive for dwindling resources, including energy and water, combined with the spread of nuclear weapons technology could make large swaths of the globe ripe for regional conflicts, some of them potentially devastating, according to a report [Global Trends 2025] released by the National Intelligence Council [in November 2008]“, is the conclusion drawn by the Washington Post [Peter Finn and Walter Pincus, Report Sees Nuclear Arms, Scarce Resources as Seeds of Global Instability, 21 Nov 2008].

The report’s executive summary states that the “lack of access to stable supplies of water is reaching critical proportions, particularly for agricultural purposes, and the problem will worsen because of rapid urbanization worldwide and the roughly 1.2 billion persons to be added over the next 20 years. Today, experts consider 21 countries, with a combined population of about 600 million, to be either cropland or freshwater scarce. Owing to continuing population growth, 36 countries, with about 1.4 billion people, are projected to fall into this category by 2025″ [p. viii]. Also, “with water becoming more scarce in Asia and the Middle East, cooperation to manage changing water resources is likely to become more difficult within and between states” [p. x].

Among a number of technology breakthroughs that could play a role by 2025, the report considers that it is probable these would include new clean water technologies “that enable faster and more energy efficient treatment of fresh water and waste water, and desalination of brackish and sea water”, such as “advances in existing technologies such as membrane bioreactors and a range of materials’ substitutions and advances” in nanotechnology”. The drivers for these technology breakthroughs are “new demands resulting from population increases and expectations that climate changes will reduce natural fresh water sources in some areas. Demand will increase for water for domestic use, as well as for agriculture (including new biopharma and biofuel crops) and industry processes”. Key barriers are “cost constraints – both in terms of energy requirements and infrastructure costs” for “both large- and small-scale systems can overcome”. “First movers to develop and deploy cheap energy-efficient clean-water technologies could gain huge geopolitical advantage”. [p. 47]

Among the new countries to be either cropland or freshwater scarce by 2025 “will be Burundi, Colombia, Ethiopia, Eritrea, Malawi, Pakistan, and Syria”. “The construction of hydroelectric power stations on major rivers may improve flood control, but it might also cause considerable anxiety to downstream users of the river who expect continued access to water” [p. 51].

“The earliest global effects of climate change, including water stress and scarcity, will begin to occur in Sub-Saharan Africa by 2025″ [p. 56].

National Intelligence Council (2008). Global trends 2025 : a transformed world. Washington, DC, USA, National Intelligence Council. ISBN 978-0-16-081834-9. Download here