Science-Policy Dialogues for Water Security: Addressing Vulnerability and Adaptation to Global Change in the Arid Americas

Abstract

www.EnvironmEntmagazinE.org voLUmE 54 nUmBEr 3 Climate change and watersupply uncertainty coupled with mounting human demands for water are straining the availability and quality of freshwater in much of the world. These twin forces cause a palpable rise in societal vulnerability, here considered as susceptibility to adverse effects of global environmental change.1 The vulnerability of water supplies (or, water vulnerability) places human communities at risk for exposure,2 or change,3 and thereby creates huge adaptation challenges. The actions being taken to reduce risks and capitalize on opportunities are considered adaptation or adaptive strategies.4 The most sensitive and vulnerable communities are those that face the greatest exposure and are most limited in their capacity to adapt. Rapidly growing and ever wealthier urban populations, expanding agribusinesses, diverse industries, extensive mining, power generation, and tourism often deprive water from or degrade its quality for use by marginalized populations of smallholder farmers and the urban poor, as well as for ecosystems along streams, lakes, and coasts recognized as biodiversity hotspots in the arid landscape. The arid5 Americas—as characterized by the southwestern United States, northwestern Mexico, north-central Chile and Argentina, and northeastern Brazil—manifest the just-described challenges especially well.6 This article focuses on two areas where our research team has been developing science-policy adaptation strategies: (1) the Sonora-Arizona drylands shared by Mexico and the United States (See map at right), and (2) the drylands east and west of the Central Andes in Chile and Argentina (see map, page 32). In these areas water remains acutely limited even as drought and flood extremes increase, ecosystems are under growing pressure, and economic globalization drives water demand. These global-change conditions threaten the security of access to water. Yet the foregoing conditions prevail—with little regard for constraints to supply, insufficient understanding of vulnerability, and inadequate attention to adaptive measures.7 To the extent that such problems are attributable to human agency,8 there is evidence that effective policies and actions can alleviate some of the harm.9 Our article describes two interactive Science-Policy Dialogues for Water Security: