Water and Climate Change
For poor countries that have always faced hydrologic variability, climate change will make water security even more difficult and costly to achieve. Climate change may also reintroduce water security challenges in countries that for a hundred years have enjoyed reliable water supplies and few, if any, water shocks. Much of the developing world will have to cope with droughts and/or the growing risk of flooding. Currently, 1.6 billion people live in countries and regions with absolute water scarcity and the number is expected to rise to 2.8 billion people by 2025.
Managing water resources using an integrated approach will be critical to mitigate social, economic and environmental impacts. Coastal zone management, water supply, and infrastructure as well as agriculture will all be affected. The effects on natural systems will be widespread: from accelerated glacier melt, altered precipitation, runoff, and groundwater recharge patterns, to extreme droughts and floods, water quality changes, saltwater intrusion in coastal aquifers and changes in water use.
The World Bank has adopted a climate-risk-management approach which focuses on the resilience of development efforts to both present-day weather variability as well as projected climate change. To help countries manage their risks, water-related investment projects will help determine the impacts of climate change on hydrology and water use, identify appropriate options, guidelines, and methodologies for adaptation.
The World Bank recognizes the importance of the water and energy nexus. The World Bank is scaling up it's support for hydropower as the largest source of renewable energy and low-carbon energy and is emphasizing demand management and energy efficiency as ways to reduce energy consumption in the provision of vital water services.
A flagship report entitled, "Water and Climate Change: Understanding the Risks and Making Climate-Smart Investment Decisions" contributes to the World Bank agenda on climate change and more specifically, informs the water sector on climate issues and climate-smart adaptation options. Using the existing knowledge and additional analysis commissioned, the report illustrates that climate change is affecting the hydrologic cycle and the projected future hydrology will have a direct impact on the water resources base availability, usage, and management.
Figure: Projected percent change in water deficit index for 2030