MLIAM
My Little Integrated Assessment Model will be build in 12 steps. MLIAM is implemented in Excel, not because it is a brilliant programming language, but because it is a friendly environment for novice programmers. Each step has three files: The data (_data) that allow you to build this particular part of the model, the model (_model) as I would build it, and the results (_results) for the exercises that illustrate policy applications of the model.* The whole package can be downloaded here. The .zip files have the model in Matlab.
Instructions and exercises are in Chapter 13. The 12 steps closely follow the chapters of the book:
Carbon cycle and climate
Emission scenarios
Abatement costs / carbon taxes
Taxes versus permits
Total impact of climate change
Marginal impact of carbon dioxide emissions
Interactions between development and climate change
Optimal climate policy
Equity and uncertainty
Uncertainty and learning
International cooperation
Adaptation policy
If you're not interested in learning how to model, but just want the model, download one of the last five versions.
* Note that you can cheat your way to a perfect result. In fact, I made it so easy that cheating does not pose an intellectual challenge or even requires any effort. If you want to be lazy and dumb, that is your problem.