Looks at how water availability and demand will evolve over the next three decades. Examines how water- and food-related policies will affect global, regional, and local water scarcity, food production, food security, the environment, and livelihoods in the long term. Collaborative work of the International Food Policy Research Institute (IFPRI) and the International Water Management Institute (IWMI). Presents and applies the IMPACT-WATER model (developed by IFPRI) which examines water and food policy and investment issues. Explores critical planning questions in water and food using PODIUM, the Policy Dialogue model (developed by IWMI).

Are we headed toward a worldwide water crisis? The increasing demand for water among households, industry, the environment, and especially agriculture is making global water scarcity a perilous possibility.What will happen to food production and global food security as water becomes increasingly scarce? What steps can we take to avert threats to global food supply, the environment, and the livelihoods of those lacking access to clean water? Using state-of-the-art computer modeling to show how water availability and demand are likely to evolve, World Water and Food to 2025 contends that if current water policies continue, so will high levels of food insecurity, environmental degradation, and water-related ill health. Further neglect of water issues could produce a genuine water crisis, which in turn could lead to a food crisis. But we can avoid these outcomes if we make fundamental policy changes now.The authors show exactly which policies and actions could ensure sustainable and efficient water use, enough food for the world’s people, and adequate drinking water for all."-- "About This Book | PR | IFPRI2; GRP38; Environment and Natural Resource Management | EPTD

Poverty, food insecurity and climate change are global issues facing humanity, threatening social, economic and environmental sustainability. Greenhouse cultivation provides a potential solution to these challenges. However, some greenhouses operate inefficiently and need to be optimized for more economical and cleaner crop production. In this paper, an economic model predictive control (EMPC) method for a greenhouse is proposed. The goal is to manage the energy-water‑carbon-food nexus for cleaner production and sustainable development. First, an optimization model that minimizes the greenhouse's operating costs, including costs associated with greenhouse heating/cooling, ventilation, irrigation, carbon dioxide (CO₂) supply and carbon emissions taking into account both the CO₂ equivalent (CO₂-eq) emissions caused by electrical energy consumption and the negative emissions caused by crop photosynthesis, is developed and solved. Then, a sensitivity analysis is carried out to study the impact of electricity price, supplied CO₂ price and social cost of carbon (SCC) on the optimization results. Finally, a model predictive control (MPC) controller is designed to track the optimal temperature, relative humidity, CO₂ concentration and incoming radiation power in presence of system disturbances. Simulation results show that the proposed approach increases the operating costs by R186 (R denotes the South African currency, Rand) but reduces the total cost by R827 and the carbon emissions by 1.16 tons when compared with a baseline method that minimizes operating costs only. The total cost is more sensitive to changes in SCC than that in electricity price and supplied CO₂ price. The MPC controller has good tracking performance under different levels of system disturbances. Greenhouse environmental factors are kept within specified ranges suitable for crop growth, which increases crop yields. This study can provide effective guidance for growers' decision-making to achieve sustainable development goals.

Hydraulic fracturing—the injection of pressurized fluid, often water, to increase recovery of oil or gas—has become increasingly popular in combination with horizontal drilling. Hydraulic fracturing improves production from a well, but requires a significant amount of water to do so and could put pressure on existing water resources, especially in water-stressed areas. To supply water needs, some water rights holders sell or lease their water resources to oil and gas producers in an informal water market. These transactions enable the opportunity for cross-sectoral investments, by which the energy sector either directly or indirectly provides the capital for water efficiency improvements in the agricultural sector as a mechanism to increase water availability for other purposes, including oil and gas production. In this analysis, we employ an original water and cost model to evaluate the water market in Texas and the potential for cross-sectoral collaboration on water efficiency improvements through a case study of the Lower Rio Grande Valley in Texas. We find that, if irrigation efficiency management practices were fully implemented, between 420 and 800 million m3 of water could be spared per year over a ten year period, potentially enabling freshwater use in oil and gas production for up to 26,000 wells, while maintaining agricultural productivity and possibly improving water flows to the ecosystem.

Increased natural and anthropogenic stresses have threatened the Earth's ability to meet growing human demands of food, energy and water (FEW) in a sustainable way. Although much progress has been made in the provision of individual component of FEW, it remains unknown whether there is an optimized strategy to balance the FEW nexus as a whole, reduce air and water pollution, and mitigate climate change on national and global scales. Increasing FEW conflicts in the agroecosystems make it an urgent need to improve our understanding and quantification of how to balance resource investment and enhance resource use efficiencies in the FEW nexus. Therefore, we propose an integrated modeling system of the FEW nexus by coupling an ecosystem model, an economic model, and a regional climate model, aiming to mimic the interactions and feedbacks within the ecosystem–human–climate systems. The trade-offs between FEW benefit and economic cost in excess resource usage, environmental degradation, and climate consequences will be quantitatively assessed, which will serve as sustainability indicators for agricultural systems (including crop production, livestock and aquaculture). We anticipate that the development and implementation of such an integrated modeling platform across world's regions could build capabilities in understanding the agriculture-centered FEW nexus and guiding policy and land management decision making for a sustainable future.