دانلود رایگان مقاله انگلیسی امنیت آب در دنیای تحول - وایلی 2018

4.1 Introduction

The global human population, currently estimated at 7.3 billion, is expected to increase by 33% to 9.7 billion by 2050. Under present conditions and policies, this is projected to require a 60% concomitant increase in agricultural production and 15% increased demand for water to meet the food needs of a projected world population of 9 billion people (World Bank, 2017). And the United Nations (UN) has estimated that, under current practices, the global water demand in developing nations alone will have increased by 400% by 2050 (United Nations World Water Assessment Programme, 2015). Combined with rising gross domestic product (GDP) in virtually all nations, which leads to increased demand for electricity, these increasing needs for water come at a time when long‐ term droughts are having impacts in highly (e.g., southwestern USA, western Canada), moderately (e.g., Brazil, Columbia), and less‐ developed (e.g., Malawi) nations alike. Global climate change adds additional uncertainly to the future regional availability of water. Often, poor policies and lack of regulations promoting water conservation lead to wasteful use, exacerbating droughts caused by natural phenomena and disproportionately affecting the poor and disenfranchised.

4.3.2 Water/Food Nexus

An example of the water/food nexus and its relationship to regional water supply and demand can be illustrated by again examining trends in the Gulf Corporation Council (GCC). The combination of a growing population and increased food production has resulted in great demands on water supplies in the GCC. For example, Saudi Arabia (KSA) quadrupled its domestic food production during the 1980s and early 1990s with a major focus on wheat production, a grain that relies on heavy use of water resources (World Bank, 2016a; Elhadj, 2014). Much of this production has now been moved outside KSA because of the severe depletion of the ground‐water supply (Sfakianakis et  al., 2010). The impact of agriculture on water is especially evident by the fact that, within KSA, dairy farms require on average 2300 gallons (8.7m3 ) of water to produce one gallon of milk (Dziuban, 2011).

This example illustrates how water supply and demand can directly impact food production and supply chains. This direct supply‐ demand relationship is analogous to the one observed for water/energy. Just as regions with low water supplies should consider electricity generation methods that require low water demands (i.e., solar PV and wind), regions with low water supplies should focus on regional food supplies that have low water demands.