Welcome

This WIKI documentation provides an overview of the Circular Economy Stylized Models developed by the partners of the CIRCOMOD project. It provides a brief description of the models, their Circular Economy features and their significance in climate mitigation. It also provides external links for further reading. This documentation supports the analytical framework of the CIRCOMOD project and stands for the deliverable 1.2 of the project.

Contrary to other types of models, the stylized models simplify complex real-world phenomena by using a set of key assumptions that avoid representing of many of the details. These models focus on capturing the main features of the Circular Economy to improve our understanding of the fundamental mechanisms, relationships, or cause-and-effect dynamics.

The Circular Economy and Climate Mitigation

The Circular Economy aims at redefining the traditional linear economy of "take-make-dispose" into a closed-loop system where waste is minimized and resources are kept in use for as long as possible. It involves redesigning products, processes, and business models to prioritize sustainability, with a focus on reducing waste, increasing efficiency, and creating value from waste materials.

The Circular Economy can play an important role in climate change mitigation by helping in the reduction of greenhouse gas emissions. By reducing waste, reusing products, and recycling materials, it reduces the need for extracting raw materials and producing new goods, which in turn reduces energy consumption and associated emissions. Additionally, the Circular Economy encourages the use of renewable energy and the development of new low-carbon technologies.

The Circular Economy provides a framework for achieving sustainable development and reducing our impact on the environment. For this reason, it is important to represent Circular Economy in climate mitigation models that primarily lack this feature. CIRCOMOD is developing Circular Economy stylized models to support and inform this effort.

Model Gallery

• A multi-agent economic model (CIRCEE), developed by the RFF-CMCC European Institute on Economics and the Environment.
• A material-enabled version of the DICE growth model, developed by the University of Utrecht.
• A building-focused industrial ecology model, developed by CML.
• A material flow consistent CGE model, developed by the University of Tilburg.
• A stylized industrial ecological model (Styl-IE), developed by the University of Freiburg.

R words coverage

The models cover the full scope of R words (Refuse, Rethink, Reduce, Reuse, Repair, Refurbish, Remanufacture, Repurpose, Recycle, and Recover) which define the core principles of the Circular Economy. The following table summarizes the Circular Economy coverage of the CIRCOMOD stylized models.

	CIRCEE	DICE-MAT	IEBUILDING	Styl-IE	MATCGE
Refuse (R0)	✗			✗	✗
Rethink (R1)	✗		✗
Reduce (R2)	✗	✗	✗	✗
Re-use (R3)	✗	✗		✗	✗
Repair (R4)	✗	✗		✗	✗
Refurbish (R5)	✗	✗		✗	✗
Remanufacture (R6)				✗	✗
Repurpose (R7)				✗	✗
Recycle (R8)	✗	✗	✗	✗	✗
Recover (R9)					✗

Model comparison

The five models offer a diversity of tools and approaches to explore the implication of the circular economy in the context of the decarbonization of our economies. This table compares the main characteristics of the models: geographical scope, sectors represented, the type of modelling, the platform used and the current status of development (in date of February 2024).

Model	Geographical scope	Sectors	Model type	Platform	Status
CIRCEE	National	Energy, industries, government, households	dynamic optimisation	dynare on matlab	completed
DICE-MAT	Global	Macro-economy	dynamic optimization	python	in progress
IEBUILDING	National	building sector	static	excel	completed
MATCGE	one region	intermediary production sectors, government, households	dynamic recursive	python	in progress
Styl-IE	one region, one sector, one material	energy, production	static	javascript	in progress