ABSTRACT

Climate change is one of many stressors facing water and natural resources managers in the semiarid regions of North America. Climate change is a particularly thorny issue, because its effects are pervasive across the landscape, across the spectrum of time scales, and there is considerable uncertainty associated with projections of future changes. In the southwestern United States and northwestern Mexico, potential changes to temperature, precipitation, runoff and aquifer recharge will interact with other significant concerns, including population growth, land-use changes, invasive plant and animal species, economic change, and sustainability of native ecosystems. Reports by the Intergovernmental Panel on Climate Change (IPCC, 2007) and the United States Climate Change Science Program (Backlund et al., 2008; Reclamation, 2011) note a reasonable likelihood of increased aridity and decreased runoff in regional watersheds.