Abstract
The range of variability present in the Earth’s climate presents a series of challenges to water managers and policy-makers. Much recent work has shed light on the detailed natural patterns of Earth’s climatic variability. including mechanisms such as El Niño and tropical monsoon systems, although there remains much to learn about their predictability. The importance of climate change as a critical factor in long-term water resources policy and planning has introduced additional significant uncertainty in the magnitude of available water resources and the risks of extremes such as floods and droughts. This chapter reviews progress in these important fields and highlights some important results that have emerged from climate science and hydrology. The chapter also considers how water policy and management can take account of these new sources of information to inform long-lived decision-making.
