The MESSAGEix framework

MESSAGEix is a versatile, dynamic systems-optimization modelling framework developed by the IIASA Energy, Climate, and Environment (ECE) Program 1 since the 1980s.

This is the documentation for message_ix, a Python package that ties together all components of the framework. message_ix and ixmp are free and open source, licensed under the APACHE 2.0 open-source license.

• For the scientific reference of the framework, see Huppmann et al. (2019) [3].

• For an overview and recent publications related to the specific MESSAGEix-GLOBIOM global model instance used at the IIASA ECE Program, see the MESSAGEix-GLOBIOM documentation.

Getting started

Modeling using MESSAGEix requires domain knowledge, understanding of certain research methods, and scientific computing skills.

• Prerequisite knowledge & skills gives a list of these items for formal and self-guided learning.

Then, continue with the:

• MESSAGEix model & framework detailed description and feature list.

• Installation of the software and essential dependencies.

• Tutorials for new users that demonstrate the basic features of the framework.

• Usage of MESSAGEix in academic publications, research projects, and derived tools.

Features of ixmp, message_ix, and related packages [3]

Mathematical specification

These pages provide comprehensive description of the variables and equations in the core MESSAGEix mathematical implementation.

• Sets and mappings

• Years, periods, and time slices

• Parameter definition

• MESSAGE core formulation

• Solve statement workflow

• Standard output reports

• Auxiliary investment parameters

• MACRO core formulation

Developing MESSAGEix models

Developing a valid, scientific MESSAGEix model requires careful use of the framework features. This section provides guidelines for how to make some common model design choices.

• Efficiency - output- vs. input defined technologies

• Add model years to an existing Scenario

• Postprocessing and reporting

• Debugging and data validation

• Calibrate and tune MESSAGE-MACRO

Using, getting help, and contributing

Everyone is encouraged to use the framework to develop energy system and integrated assessment models!

• Python API

• Usage in R via reticulate

• What’s New —release history and migration/upgrade notes.

• User guidelines and notice —including how to properly cite the framework and software in scientific research.

• Contributing to development —we welcome enhancements to the framework itself that enable new features across all models.

• Sharing publications, projects, and tools—we invite the sharing of the usage of the MESSAGEix framework.

• Frequently asked questions

• References

Have a question? Check…

• …on GitHub:

  • Join an existing discussion or start a new one with your question.

  • Search current issues, or open a new one to report a bug in the code.

• …the Frequently asked questions.

• …the message_ix Google Group, either online or via e-mail at <message_ix@googlegroups.com>.

1

Known as the “Energy Program” until 2020-12-31.