امنیت آب در دنیای تحول Water Security in a Changing World

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. Herein we address two aspects of water security: water quality and water quantity. Recent decades have seen increased access to  safe drinking water. By 2010, 89% of the global population were using potable water, which was an increase in over two billion people in the previous 20 years. Still, nearly one billion people lack access to sufficient quantities of safe water for drinking, food preparation, and hygiene. The UN Committee on Economic, Social and Cultural Rights, through the adoption of General Comment No. 15 (United Nations, 2002), recognized the human right to water, further defined as “the right to sufficient, safe, acceptable and physically accessible and affordable water for personal and domestic uses.” More recently, the UN General Assembly, through adoption of Resolution 64/292, recognized the human right to clean drinking water and sanitation (United Nations, 2010). Access to safe water goes hand in hand with proper sanitation and treatment, which is lacking in some regions.