Understanding Climate Model Data

Preparing information on future climate for risk assessment generally involves processing climate data in a series of climate models. This is often called the ‘top-down’ approach[1] because it generally starts with global climate model (GCM) simulations, forced with a range of greenhouse gas emissions scenarios, that are subsequently downscaled and applied to assess regional impacts through impact models, as illustrated below.

Before working with future climate data, it is useful to review some fundamental processes and concepts that are important considerations when dealing with climate models and climate projections in each step of this process. These include:


[1] Dessai S, Hulme M. 2004. Does climate adaptation policy need probabilities? Climate Policy, 4, 107–128. Note: this paper also introduces an alternative called the ‘bottom-up’ approach which focuses toward understanding social vulnerability under current climate, with a unit of analysis is commonly at household or communities level and the temporal scale is usually more immediate and near term than those used in the top-down approach.