General FAQs

What is the purpose of En-ROADS?

The purpose of En-ROADS is to improve decision-maker understanding of the dynamics of the climate-energy-land-economic system, particularly focusing on policy-makers, citizens, and business leaders.

En-ROADS is designed to provide a synthesis of the best available science on climate solutions and put it at the fingertips of groups in policy workshops and role-playing games. These experiences enable people to explore the long-term climate impacts of global policy and investment decisions.

What sort of model is En-ROADS?

The En-ROADS (Energy - Rapid Overview And Decision Support) simulator is a System Dynamics model. It was built in Vensim modeling language and transformed into an online simulation via the “SD Everywhere” converter built by Climate Interactive and Todd Fincannon.

En-ROADS is an extension of (and contains most all of) the C-ROADS simulator, which focuses on international dynamics.

How did you build confidence in En-ROADS?

In order to build confidence, we conducted a full suite of tests guided by section 21.4 of the book Business Dynamics by John Sterman. For more detail, please see the En-ROADS Reference Guide.

Given the existence of many other climate models, one of the most important tests was the comparison of En-ROADS output to the output of disaggregated simulations from the SSP and EMF suites given a range of emissions input scenarios.

What are your biggest critiques of the model, and possible future areas of improvement?

Some critiques and areas of improvement include:

  1. Global aggregation limits treatment of heterogeneity between regions and countries.

  2. The level of detail limits tactical planning of energy system. It is not a “bottom-up” model.

  3. The global economy in the model is not fully endogenous – it does not model welfare:

    • Growth of GDP per capita is specified by the user; assumes regional convergence of GDP per capita at 1%/year over time
    • Sources and uses of funds for subsidies and taxes are not accounted for (e.g., revenue recycling from a carbon price)
    • Some technology policies are costless
    • Implicit, transient non-conservation of money and unserved demand possible
  4. Equity, non-climate environment, health and other effects are excluded.

  5. Some inputs (e.g., energy supplies) specify taxes or subsidies to drive change in the system while others (e.g., energy efficiency, methane emissions, deforestation) directly drive change, avoiding the taxes or subsidies that might drive the change.

  6. While En-ROADS includes multiple feedback processes (e.g., carbon fertilization and carbon saturation), it does not yet include the effects of various biogeochemical feedback processes such as the positive feedback due to the albedo effect or the release of methane from permafrost.

Who created the En-ROADS System Dynamics model?

En-ROADS was created by Climate Interactive, the MIT Sloan Sustainability Initiative, and Ventana Systems.

It is based on research originally conducted in the mid 1990s at MIT, and has been developed by a partnership of MIT’s Sloan School of Management, Ventana Systems, and Climate Interactive. The lead modeler at Climate Interactive is Dr. Lori Siegel and at Ventana Systems, Dr. Thomas Fiddaman, whose 1997 MIT doctoral dissertation forms the foundation of the carbon cycle and climate sector. Professor John Sterman of MIT Sloan oversees the modeling science.

Who is on the En-ROADS development team?

  • Bindu Bhandari, Climate Interactive
  • Cassandra Breeze Ceballos, Climate Interactive
  • Linda Cheung, Climate Interactive
  • Dr. Tom Fiddaman, Ventana Systems
  • Todd Fincannon, Climate Interactive
  • Dr. Travis Franck, Climate Interactive
  • Dr. Jack Homer, Homer Consulting
  • Ellie Johnston, Climate Interactive
  • Andrew Jones, Climate Interactive
  • Dr. Charles Jones, Climate Interactive
  • Dr. Florian Kapmeier, Reutlingen University
  • Stephanie McCauley, Climate Interactive
  • Dr. Phil Rice, Climate Interactive
  • Caroline Reed, Climate Interactive
  • Dr. Juliette Rooney-Varga, U-Mass Lowell
  • Dr. Elizabeth Sawin, Climate Interactive
  • Dr. Lori Siegel, Climate Interactive
  • Dr. John Sterman, MIT System Dynamics Group
  • Yasmeen Zahar, Climate Interactive

Where does the financial support behind En-ROADS come from?

The development and use of En-ROADS has been supported by ClimateWorks, the Hewlett Foundation, the Goldman-Sonnenfeldt Foundation, Active Philanthropy, Zennström Philanthropies, the KR Foundation, the Morgan Family Foundation, The Why Wait Fund, The Rockefeller Brothers Fund and others.

In-kind contributions have been made by multiple project partners.

What data does En-ROADS use?

En-ROADS was built using the best available science and data, with sources such as the IEA, the EIA, and the IPCC. The En-ROADS model is driven by its own equations, not external datasets, and is calibrated against history and projections. Default values and bounds on economic, energy, and climaterelated dynamics have been determined from an extensive review of literature.All parameters and equations are available in the En-ROADS Reference Guide. The model was externally reviewed by a team of scientists and modelers, chaired by Dr. John Weyant, who leads the Energy Modeling Forum out of Stanford University. For those interested, many parameters or assumptions that we make can be changed in the “Assumptions” view. What does the “business as usual” or “reference scenario” most closely match in the climate literature? ———————————————————————————————————-

When comparing Radiative Forcing of the En-ROADS reference scenario against the RCP scenarios from other more disaggregated models, the En-ROADS scenario is lower than RCP 8.5 and higher than RCP 6.0.

Amongst the Shared Socio-Economic Pathways (SSPs), the reference scenario mostly closely matches SSP2 — Middle of the road (medium challenges to mitigation and adaptation.

What simulations similar to En-ROADS can I explore?

For a more technical approach, we suggest reviewing the 18 models in The Energy Modeling Forum suite, organized by Stanford University.

For a similar approach with an accessible online interface, explore The Global Calculator.

Where can I learn about the science, assumptions, testing, and background of the En-ROADS simulation?

All assumptions and equations are documented in the En-ROADS Reference Guide.

Assumptions most relevant to model users are available within other sections of the online and searchable user guide.

Other supporting materials on modeling science are available on our website.

Whom can I contact for more information?

For more information on En-ROADs, please visit the En-ROADS web page or contact info@climateinteractive.org.