With the increasing concern for anthropogenic climate change in recent years, the predictions of an increase in the global mean temperature made by climate models have become an integral part of the discussion. These models are supposed to accurately represent the Earth system. How accurately does it do that? How accurate are the forecasts that they produce?

This web book, developed as a project for the Global Change Toolkit course at The University of Arizona, attempts to answer some of these questions. This is intended to introduce global climate modeling to the educated layperson or to a scientist who is a novice to global climate modeling. For that reason, this web book is designed to explain the modeling process in very basic terms. If you're an expert in the field, you will probably find this lacking in mathematical rigor but hopefully not in scientific rigor. For those looking for a little bit more math, I would suggest reading:

Kevin Trenberth, Ed., 1992: Climate System Modeling. Cambridge Univ. Press: Cambridge, UK.

Warren Washington and Claire L. Parkinson, 2005: An Introduction to Three-Dimensional Climate Modeling. University Science Books: Sausalito, Calif.

1. What is Climate?
Radiation: What Drives the Climate
The Components of the Earth System
2. What is a Climate Model?
A Short History of the Development of Climate Models
The Difference Between Climate Modeling and Numerical Weather Prediction
The Ensemble of Climate Models
3. The Components of a Climate Model
Atmospheric Models
Ocean and Sea Ice Models
Land Models
Offline Mode
4. What is Next for Global Climate Modeling?
Transitioning to Earth System Modeling
The Need for Increased Resolution