Climate change adds uncertainty to already complex global water challenges. Though no standard method has been adopted yet by the World Bank, common practice uses downscaled precipitation and temperature projections from Global Climate Models (GCMs) as input to hydrologic models. While this has been useful in some applications, they often give too wide a dispersion of readings to provide useful guidance for site-specific water resources management and infrastructure planning and design. Rather than design for an uncertain situation selected a priori, the so-called “bottom-up” approaches explore the sensitivity of a chosen project to the effects of uncertainties caused by climate change. Supported by the Water Partnership Program, this book summarizes alternatives explored by a group of organizations that belong to the Alliance for Global Water Adaptation (AGWA), to provide practitioners with the tools to adapt to the realities of climate change by following a decision-making process that incorporates bottom-up thinking.
