En-ROADS Simulator Science
En-ROADS is a System Dynamics model with origins in the MIT PhD theses of Dr. John Sterman and Dr. Tom Fiddaman. Recent breakthroughs have enabled the model to be made user friendly and accessible to wide audiences. The modeling team at Climate Interactive, led by Dr. Lori Siegel, have taken on the more recent model developments in continued collaboration with MIT Sloan’s John Sterman, Ventana System’s Tom Fiddaman, and many others.
En-ROADS is a global model that focuses on how changes in the energy, economic, and public policy systems could affect greenhouse gas emissions and climate outcomes. Behind the simulator is an extensive study of the literature of important factors such as delay times, progress ratios, price sensitivities, historic growth of energy sources, and energy efficiency potential. En-ROADS stands for Energy Rapid Overview and Decision-Support.

En-ROADS is a high-order, non-linear differential equation model that is built in Vensim software. We then translate En-ROADS into WebAssembly via a tool we built with Todd Fincannon called SDEverywhere so that it can run in a web browser. When a user moves a slider, the En-ROADS application calculates the results from ~14,000 equations, with a time step of ~45 days, over 110 years from 1990 to 2100, in 60 milliseconds. If you like En-ROADS, you may appreciate exploring the larger, more disaggregated models that our modeling team used to test and calibrate our simulator. One group of models is the Energy Modeling Forum out of Stanford University, which includes 18 energy-economy and integrated assessment models.
All assumptions, equations, and parameters are documented in the En-ROADS Reference Guide (~400 pages). If you have a question about the model, be sure to check out the Climate Interactive Support Desk – we have a FAQ database of knowledge or our team can help you with a specific question. A brief overview of the insights from academic literature supporting the need for En-ROADS is here.
To learn more about En-ROADS’ model structure and testing, we encourage you to sign up for the free Mastering En-ROADS Training Program, and explore some of our videos on the subject (like the one below).