Over the last 50 years, the Earth's population doubled and the global food system responded remarkably to the increase in food demand. This was done through just a modest increase in total cropland — not more than 12 percent. The achievement occurred mainly through intensification of agricultural production, i.e. an increase in yield and cropping intensity, which in turn would not have been possible without irrigation. Irrigated land has increased proportionally much faster than land under rainfed agriculture. In fact, while the world's cultivated area has grown only by 12% over the last fifty years, irrigated area has doubled over the same period, accounting for most of the net increase in cultivated land. Meanwhile, agricultural production has grown between 2.5 and 3 times, thanks to significant increase in the yield of major crops.
Globally, some 300 million hectares of farmland is irrigated, accounting for 70% of all freshwater appropriations. That is happening on only 20% of the world's cultivated land — yet at the same time, that irrigated land accounts for 40% of all agricultural production and 60% of cereal production.
Toward 2050, rising population and incomes are expected to require 70 percent more food production globally, and up to 100% more in developing countries. But some regions are coming very close to their potential to intensify food production, which is already leading to tension on access to natural resources, in particular water. East Asia and The Middle East are operating very close to their limits and will not be able to extend their agriculture much further, while substantial potential is still available in Latin America and in sub-Saharan Africa.
The production of 1 calorie of food requires 1 liter of water. With the world's average daily caloric requirement at about 2800 per person, the water needed to satisfy the daily food requirements of each individual on the planet is about 2 800 liters. Or to put it another way, to produce one hamburger it takes 2 400 liters of water. A glass of milk? 200 liters. One egg — 135 liters. A slice of bread takes 40 liters.
The rapid growth of urban population - described as one of the world's major demographic trends - has triggered an explosion of "mega cities" in Asia, Latin America and Africa, causing a breakdown in basic services, including water supplies and sanitation facilities. In 2000, nearly one third of the world's urban dwellers lived in slums, By 2050, about 70 percent of the world's population will live in urban areas causing horrendous problems, predicts a new study released by the World Wildlife Fund (WWF).
The study focuses on six of the world's "exploding mega cities": Mexico City, Mexico, with a population of 21.1 million; Buenos Aires, Argentina, with a population of 12.8 million; Kolkata, India, with a population of 15.4 million; Karachi, Pakistan, with a population of 18 million; Nairobi, Kenya, with a population of 3.5 million; and Shanghai, China, with a population of 23 million.
In Karachi, Pakistan, around 30,000 people die due to the effects of contaminated drinking water.
In Kolkata there are both traces of faeces in drinking water and high concentrations of arsenic in ground water.
Shanghai is now facing water shortages and problems related to salination.
In Kenya, 60 percent of Nairobi's inhabitants live in informal settlements with inadequate access to quality water and are forced to buy their water at kiosks at a higher price.
In Mexico City, excessive overexploitation of groundwater has led to the sinking of the city over time by five to 10 centimetres and depends on pumping water from areas about 150 kilometres away.
The rivers of Buenos Aires are described as "public cesspits", there are high levels of dumped toxins making the Argentine river Matanza-Riachuelo "one of the world's most polluted waterways". And millions of people in the city lack safe access to drinking water and are not connected to sewer systems.
Anna Forslund, WWF's fresh water expert based in Sweden, said: "Rapid uncontrolled urbanisation is definitely a threat to the ecosystems we all depend on."
Yemen, the poorest country in the Arab world, is the region’s most water insecure country. While the international poverty line is 1,000 cubic metres of water per person per year, it gets just 200. Of the country’s 21 main aquifers, 19 are no longer being replenished, according to its environmental protection agency. Its government may have to move the capital Sana’a and its two million people, because it is expected to have run dry within six years. Lack of water also causes food insecurity. Subsistence farmers can’t feed their families, meaning Yemen imports between 80 per cent and 90 per cent of its food. Unless subsidised, food prices are vulnerable to global market fluctuations and rising food prices lead to political unrest and instability.
The Gulf countries and much of North Africa rely heavily on desalination plants for their water needs: there are more than 1,500 situated beside the Gulf and the Mediterranean. They are energy-intensive and expensive and, although costs are falling, they also have an environmental price. Salt and impurities extracted from the water mostly end up back in the sea or in aquifers, affecting fish, coral and other marine life. Salt levels in the Arabian Gulf are eight times higher in some places than they should be.
“The German-led Desertec initiative is an innovative idea that needs to be explored further,” says Prince El Hassan bin Talal of Jordan says, who was one of its founding members.“More than 90 per cent of the world’s population could be served by clean power from deserts thanks to high-voltage DC cables. My fear though is that we could see something like a solar conveyor belt from the Gulf or the North of Africa to Europe. It would benefit the users of the electricity and the solar industry but may ignore the marginalised communities from where the power is being transmitted. There simply has to be an emphasis at the local level on these communities. We should also ask if we developed a solar desalination and a solar power installation in Gaza, for example, would this begin to change the nature of the problems in such places? People need a clearly defined vision of their future in a participatory society with a participatory economy.”
In 2002, the UK and Italy backed Medrep, a programme to develop solar energy projects in 10 countries around the Mediterranean, but it too has struggled to get beyond the research and pilot project phases. It had a budget of just €4 million and its steering committees met twice a year. “These types of projects need a serious political and strategic framework. We need to appoint people who will do the work and not just talk. At the moment, we’re appointing the likes of ambassadors. They don’t do the work and just talk about politics. These plans can work if the people are serious and responsible. The people need real technical and financial means behind them. These initiatives need a critical mass to build up before they can really start to make progress” Dr Arab Hoballah, an economist with the United Nations Environment Programme’s (UNEP) technology, industry and economics divisionsays.
“If these funds can buy football teams, then they can be used in the Mediterranean region and other countries to help build peace." Hoballah argues. “But geopolitics is a real constraint. In this region, we do politics and war before we do development and peace. We find the money for war, but when it comes to building peace, we don’t have the money. Would a country like France want this type of investment in the Middle East or North Africa, rather than loan it to a country that will buy the arms it manufactures?”
The Sahara Forest Project: a combined solar energy, sustainable water and agriculture initiative led by Michael Pawlyn, the founder of Britain’s Eden Project and backed by the governments of Jordan, Norway and the Bellona Foundation, a Norwegian NGO. Essentially the Sahara Forest Project combines a number of existing technologies into an integrated system, using sunlight, deserts, carbon dioxide and seawater to produce food, water and energy.
Earlier this year an agreement was signed to build a demonstration centre on 20 hectares in Aqaba on the Jordanian coast next year, and the Sahara Forest Project team has signed a second agreement to develop a new trial project in Qatar. The Qatar project has secured new backing from a company based there called Qafco, the world’s largest producer of ammonia and urea-based fertiliser, and Yara International, a Norwegian fertiliser company. While already initiated in Aqaba, a comprehensive feasibility study is now under way in Qatar. Both companies will provide financial, technical, and research and development support to the Sahara Forest Project, with a view to finding ways of creating environmentally friendly fertiliser that can be used in desert areas.
By 2050, the founders of the project say that their greenhouses, built on 198,000 hectares (28 square miles – or about one and a quarter the size of Manhattan) could employ up to two million people. Different areas will support projects of different sizes, but solar power installations would take up another 73 sq km, with green vegetation outside the greenhouses taking up a total area of 15 sq km – that is equivalent to an area 16 times the size of Co Dublin. The output of the projects would include fruit and vegetables or biodiesel from microalgae, depending on the suitability at each location. Salt, freshwater and vapour from freshwater would also be produced. Solar-generated power would be exported to the grid to supply surrounding communities.
The statistics that prove the need for innovative projects such as this are stark, according to the Sahara Forest Project team:
- Desertification and land loss across the globe represent lost income of $42 billion per year
- The barren lands lost every year could have provided 20m tonnes of grain
- Water use for crop irrigation must double by 2050 if it is to meet the Millennium Development Goals on hunger, according to UNEP figures
- As the global population approaches 9 billion by 2050, the demand for water and land-intensive meat and cereal is predicted to increase by at least 50 per cent
- By 2050, up to 4 billion people could be living in water-scarce areas
China is the source of cross-border river flows to the largest number of countries in the world – from Russia to India, Kazakhstan to the Indochina peninsula. Getting this pre-eminent riparian power to accept water-sharing arrangements or other co-operative institutional mechanisms has proved unsuccessful so far in any basin. Instead, the construction of upstream dams on international rivers such as the Mekong, Brahmaputra or Amur shows China is increasingly bent on unilateral actions, impervious to the concerns of downstream nations.
China already boasts both the world’s biggest dam (Three Gorges) and a greater total number of dams than the rest of the world combined. It has shifted its focus from internal to international rivers, and graduated from building large dams to building mega-dams. Among its newest dams on the Mekong is the 4,200 megawatt Xiaowan – taller than Paris’s Eiffel Tower. New dams approved for construction include one on the Brahmaputra at Metog (or Motuo in Chinese) that is to be twice the size of the 18,300MW Three Gorges – and sited almost on the disputed border with India.
The consequences of such frenetic construction are already clear.
First, China is in water disputes with almost all its neighbours, from Russia and India to weak client-states such as North Korea and Burma. Worse, although there are water treaties among states in south and south-east Asia, Beijing rejects the concept of a water-sharing arrangement. It is one of only three countries that voted against the 1997 UN convention laying down rules on the shared resources of international watercourses. Yet water is fast becoming a cause of competition and discord between countries in Asia, where per capita freshwater availability is less than half the global average. The growing water stress threatens Asia’s rapid economic growth and carries risks for investors potentially as damaging as non-performing loans, real estate bubbles and political corruption.
Second, its new focus on water mega-projects in the homelands of ethnic minorities has triggered tensions over displacement and submergence at a time when the Tibetan plateau, Xinjiang and Inner Mongolia have all been wracked by protests against Chinese rule. Third, the projects threaten to replicate in international rivers the degradation haunting China’s internal rivers.