Water resources, climate change and energy

The objective of this chapter is to summarise our understanding of the physical interactions between water resources, energy use, and climate change and mitigation. The distribution and pressures on our water resources will be reviewed, as well as our current understanding of observed and projected changes due to climate change. By addressing a set of relevant questions, the aim is to provide a framework within which we can interpret which interactions are likely and which less likely; which are desirable and which not desirable. The questions addressed include the following: What are the characteristics, drivers and challenges of water resource management? Why do water resource management challenges vary between countries? Are concepts like green and blue water, embedded water, peak water and integrated water resources management useful in managing the relationship between water, climate and energy? What are the observed and projected impacts of climate change on water resources? Why does it seem that climate change makes water management harder everywhere? Does it matter whether climate change is man-made? How do melting ice caps and glaciers affect water resources? What is the relationship between drought and water resources? How do climate change, floods and water resources interact? Will climate change affect water use? What are the potential impacts of water management on climate and energy security? What adaptation measures are considered in water management? What is their influence on energy security and climate mitigation measures? For example, can changes in water management change climate? What do water management changes mean for energy use? How can climate mitigation and energy security measures impact on water security? Can switching between energy sources affect water security? What impact do the by-products of energy generation have on climate and the water cycle? What is the impact of climate mitigation measures such as landscape carbon storage?