Water scarcity: a threat to global food supply

For hundreds of millions of poor farmers in developing countries, lack of access to water for growing food is the major constraint they face - and the situation could get worse. Research by the International Food Policy Research Institute (IFPRI) shows that if current trends in water policy and investment do not change for the better, by 2025, water scarcity will cause annual global losses of 350 million metric tons of food production - slightly more than the entire current US grain crop.

Declining food supplies could cause prices to skyrocket, leading to significant increases in malnutrition, since many poor people in developing countries already spend more than half their income on food.

However, reforms in water policy and investment are not only possible, but feasible, and could lead to sustainable water use. In addition, increased investments in crop research, new technologies, rural infrastructure, and conservation measures could both boost water productivity and increase crop yields. A number of small-scale technologies and community-level water management innovations have already emerged in recent years.

Nonetheless, feeding the world’s growing population will largely depend on irrigation, but increased competition for water will severely limit its availability for this purpose, which in turn would seriously constrain food production. Due in part to rapid population growth and urbanisation in developing countries, water use for households, industry, and agriculture is expected to increase by at least 50 per cent in the next 20 years.

Increasing scarcity is mainly due to slow growth in new water supplies, which in turn is due to the high cost of dams (including environmental and social costs), irrigation infrastructure, and domestic and industrial water supply. The extremely rapid rise in demand for domestic and industrial water, particularly in developing countries, is also a major factor.

For the first time in world history, demand for water for non-agricultural uses is growing more rapidly than is water demand for agricultural purposes. A significant amount of the water used by households and industries will be at the expense of irrigation.

In addition to increased competition for water from other sectors, declining water quality, falling groundwater tables, and growing environmental demands for water will continue to negatively affect agricultural production.

Several new challenges and opportunities are also on the horizon for agriculture-related water management, including explosive growth in aquaculture production, biotechnology, climate change, and increasing climate variability - with various environmental consequences.

Given these challenges, and in the absence of policy and investment reform, environmental needs and food production will be in competition for water in many parts of the world. Water scarcity could easily get much worse if national governments and international donors do not change their investment priorities and commit to fundamental changes in water policies.

However, a crisis is not inevitable. Achieving sustainable water use and ensuring adequate supplies of and access to water for food production is possible. Three broad strategies could address the challenge posed to food security by increasing water scarcity, particularly among the world’s poor:

• improving crop productivity, with respect to both land and water, through agricultural research and better policies;
• increasing the supply of water for irrigation, as well as household and industrial purposes, through carefully targeted investments in infrastructure; and
• conserving water and enhancing its efficient use through improved water management and policy reform.

But we must act now to adopt and implement these measures. The required strategies take not only money and political will, but time as well, and time is of the essence. Water is not like oil. There is no substitute. If we continue to take it for granted, much of the Earth will run short of water or food - or both.