ABSTRACT
Climate scenarios are descriptions of how the Earth's climate may differ in the future compared to its present-day state, which are simulated by global climate models (GCMs) driven by a set of emission scenarios describing future changes in human activities, including land use and anthropogenic greenhouse gas emissions. To assess water availability, climate information at a local or regional scale may be needed. This requires downscaling of results provided by GCM simulations, using regional climate models (RCMs), and/or statistical downscaling methods. This chapter aims to (1) establish a link between water, sustainable development and climate change; (2) introduce key concepts and methods used for the projection of future climate; (3) describe the chain of assumptions and calculations used for scenario production; (4) describe key modelling tools, such as GCM and RCM, alongside statistical downscaling methodologies used for constructing future scenarios; (5) present the state-of-the-art of emission and climate change scenarios used by the United Nation's Intergovernmental Panel on Climate Change (IPCC) in its latest report; (6) discuss uncertainties in future climate change scenarios; and (7) highlight useful resources for making or using past climate data and future climate scenarios, which can be a benefit in the water-related studies.
