Version 2.0.0

This is RICE50+, a multi-regional Integrated Assessment Model, described in the paper Gazzotti et al. (2021): 'Persistent inequality in economically optimal climate policies', Nature Communications, 12, Article number: 3421, https://www.nature.com/articles/s41467-021-23613-y

A calibrated multi-regional Integrated Assessment Model with 50+ regions, calibrated abatement cost curves, a modular and phase structure of the code, and additional optional modules.

1. Installation: Install GAMS, Github Desktop, (and optionally VSCode as advanced editor)

• GAMS from https://www.gams.com/download/ (Run the installer in advanced mode and mark the check-box Add GAMS directory to PATH environment variable).
• GitHub Desktop from https://desktop.github.com/ and log-in with your personal GitHub Account.
• VisualStudio Code from https://code.visualstudio.com/ (optional)

2. GAMS license

• In order to run the model, you need a GAMS license and CONOPT or KNITRO license. You can request a temporary license from gams https://www.gams.com/download/ but for serious model runs you will need a full license, academic and non-for-profit versions might be available. Once you obtain the license as gamslice.txt file, copy this file to your GAMS folder.

3. Get the source code of the RICE50x model: Either cloning it in Github desktop (preferred), download it from https://github.com/witch-team/RICE50xmodel, or using git at the command line.

4. Download and unzip calibrated input data from https://github.com/witch-team/RICE50xmodel/releases/download/v2.0.0/data_ed57.zip and into the same folder.

5. Run the model in gamsIDE (creaing a project file in the RICE50x folder) or on the command line:

gams run_rice50x.gms

6. [OPTIONAL] Analyze and visualize model output, using the produced results_*.gdx files in the RICE50x folder. This can be done in GAMS itself, or exporting to Excel, or using your sofwrate of choice with a gdx importing possibility. You can also get the "witch-plot" repository from github (https://github.com/witch-team/witch-plot) download it to the same root folder as RICE50x, and after running the model, launch teh interactive visualization tool:

Rscript plotgdx_rice50x.R

What follows is a summary of main model settings. Bold elements are model default values.