Global Climate Models

Abstract

Global climate models are three‐dimensional representations of the climate system and its components. Using mathematical equations, climate models can simulate the exchange of air, water, and energy between components, given user‐specified input parameters. Using model validation techniques and sensitivity studies, climate modelers can assess a model's accuracy in simulating global climate change as well as establish a cause‐and‐effect relationship between various climate drivers and observed changes. Projections of future global climate change can be obtained by specifying different scenarios of future greenhouse gas emissions. Output from global climate models can take the form of a time series of global change in a particular climate variable (such as temperature), or of a global map depicting the spatial pattern of change in that variable at a future point in time. A great deal of uncertainty is associated with climate modeling, stemming from unknown future emissions, intermodel uncertainty, and uncertainty about various climate processes.