Mats Lannerstad

Assessing the water challenge of a new green revolution in developing countries

This article analyzes the water implications in 92 developing countries of first attaining the 2015 hunger target of the United Nations Millennium Development Goals and then feeding a growing population on an acceptable standard diet. The water requirements in terms of vapor flows are quantified, potential water sources are identified, and impacts on agricultural land expansion and water tradeoffs with ecosystems are analyzed. This article quantifies the relative contribution from infiltrated rainwater/green water in rain-fed agriculture, and liquid water/blue water from irrigation, and how far water productivity (WP) gains can go in reducing the pressure on freshwater resources. Under current WP levels, another 2,200 km3·yr−1 of vapor flow is deemed necessary to halve hunger by 2015 and 5,200 km3·yr−1 in 2050 to alleviate hunger. A nonlinear relationship between vapor flow and yield growth, particularly in low-yielding savanna agro-ecosystems, indicates a high potential for WP increase. Such WP gains may reduce additional water needs in agriculture, with 16% in 2015 and 45% by 2050. Despite an optimistic outlook on irrigation development, most of the additional water will originate from rain-fed production. Yield growth, increasing consumptive use on existing rain-fed cropland, and fodder from grazing lands may reduce the additional rain-fed water use further by 43–47% until 2030. To meet remaining water needs, a cropland expansion of ≈0.8% yr−1, i.e., a similar rate as over the past 50 years (≈0.65% yr−1), seems unavoidable if food production is to occur in proximity to local markets.

Urban consumption of meat and milk and its green and blue water footprints—Patterns in the 1980s and 2000s for Nairobi, Kenya

THE PROBLEM Various studies show that the developing world experiences and will continue to experience a rise in consumption of animal proteins, particularly in cities, as a result of continued urbanization and income growth. Given the relatively large water footprint (WF) of animal products, this trend is likely to increase the pressure on already scarce water resources. AIM We estimate, analyse and interpret the changes in consumption of meat and milk between the 1980s and 2000s for three income classes in Nairobi, the ratio of domestic production to imports, and the WF (the volume of freshwater consumed) to produce these commodities in Kenya and abroad. RESULTS Nairobis middle-income class grew much faster than the overall population. In addition, milk consumption per capita by the middle-income group grew faster than for the citys population as a whole. Contrary to expectation, average meat consumption per capita across all income groups in Nairobi declined by 11%. Nevertheless, total meat consumption increased by a factor 2.2 as a result of population growth, while total milk consumption grew by a factor 5. As a result, the total WF of meat consumption increased by a factor 2.3 and the total WF of milk consumption by a factor 4.2. The increase in milk consumption was met by increased domestic production, whereas the growth in meat consumption was partly met through imports and an enlargement of the footprint in the countries neighbouring Kenya. DISCUSSION AND CONCLUSION A likely future rise in the consumption of meat and milk in Nairobi will further enlarge the citys WF. Given Kenyas looming blue water scarcity, it is anticipated that this WF will increasingly spill over the borders of the country. Accordingly, policies aimed at meeting the rise in demand for meat and milk should consider the associated environmental constraints and the economic implications both nationally and internationally.

Planned and Unplanned Water Use in a Closed South Indian Basin

Intensive irrigation development brought the Bhavani basin in southern India to ‘allocation closure’ in the 1950s, with all available surface water being assigned to various uses. In spite of this, policies and investments have supported further intensified water use, some well planned, but many unplanned from a basin perspective. At present, individuals acting independently and domestic water schemes are important drivers. The basin is moving towards ‘hydrologic closure’, with little water leaving the basin. While agriculture in the basin is showing no signs of collapse, people are demanding more water, leading to a ‘perception-wise’ closure. The changes in use and perception underscore the need for a basin-wide perspective that considers consumptive water use as well as river diversions.

Pumped Out : Basin Closure and Farmer Adaptations in the Bhavani Basin in Southern India

Mainstream views of water resource development focus on conventional concepts of supply and demand and often conceive of river basin development as a linear and rational process of harnessing natur ...

Adaptive water resource management in the South Indian Lower Bhavani Project Command Area

This study explores the theory and practice of Adaptive Management (AM) based on a detailed field study. To what extent farmers and water resource managers already practice AM; and whether it is pr ...

Freshwater resources under success and failure of the Paris climate agreement

Population growth will in many regions increase the pressure on water resources and likely increase the number of people affected by water scarcity. In parallel, global warming causes hydrological changes which will affect freshwater supply for human use in many regions. This study estimates the exposure of future population to severe hydrological changes relevant from a freshwater resource perspective at different levels of global mean temperature rise above pre-industrial level (1Tglob). The analysis is complemented by an assessment of water scarcity that would occur without additional climate change due to population change alone; this is done to identify the population groups that are faced with particularly high adaptation challenges. The results are analysed in the context of success and failure of implementing the Paris Agreement to evaluate how climate mitigation can reduce the future number of people exposed to severe hydrological change. The results show that without climate mitigation efforts, in the year 2100 about 4.9 billion people in the SSP2 population scenario would more likely than not be exposed to severe hydrological change, and about 2.1 billion of them would be faced with particularly high adaptation challenges due to already prevailing water scarcity. Limiting warming to 2 C by a successful implementation of the Paris Agreement would strongly reduce these numbers to 615 million and 290 million, respectively. At the regional scale, substantial water-related risks remain at 2 C, with more than 12 % of the population exposed to severe hydrological change and high adaptation challenges in Latin America and the Middle East and north Africa region. Constraining 1Tglob to 1.5 C would limit this share to about 5 % in these regions.