Scope of Payment for Ecosystem Services Mechanism for ... - icimod

CHAPTER 11 INTRODUCTION1.1 Background:Fresh water is becoming a scarce resource. In fact, the scarcity of clean and fresh water isone of the world‟s most pressing environmental problems (Arms, 2008). With anincreasing population, the welfare and changes in food consumption and lifestyle patternhave considerably increased water use. Slightly more than one-half of available freshwater supplies are currently used for human use. The world water demand doubles every20 years (USAID, 2003). Water resources are increasingly over-exploited, influencingriver discharge and groundwater level.Water is critical to social and economic development. Over-exploitation of waterresources directly affects human society, and threatens the sustainability of the naturalresources base. Since 1950, world population has doubled while water use has tripled(ECA, 2006). By 2025, more than 2.8 billion people or- 35% of the world‟s projectedpopulation- will live in 48 countries facing water stress or water scarcity (USAID, 2003).According to the UN Water Assessment Program, by 2050, 7 billion people in 60countries may have to cope with water scarcity (Chenoweth, 2008; Abaje et al, 2009).Water scarcity is emerging as one of the most pressing problems of the 21 st century(ECA, 2006).Watersheds are a source of economic goods that are vital to livelihoods and economies,and provide spaces for recreation and cultural heritage (PEDRR, 2011). The totalavailable water in a watershed mainly depends on precipitation and internal renewableresources which are replenished by rainfall. In many places, human activities are causingwatersheds to deteriorate thereby affecting water supply and its quality.Ecosystems provide multiple direct and tangible benefits to humankind as well asintrinsic ecosystem services. Many of these ecosystem services are being degraded orused unsustainably. Over the past 50 years, watersheds namely supply of fresh water andwater purification, and to a lesser extent water-regulation services, have degradedsignificantly (MEA 2005; Porras et al. 2008). The Millennium Ecosystem Assessment(M.A., 2005) states“ ecosystems control the character of renewable freshwater resources1