Some critiques and areas of improvement include:
En-ROADS presents results at a global level of aggregation. This limits discussion of heterogeneity between regions and countries. The model underneath En-ROADS has more details and makes assumptions reflecting these regional differences, but the results are still presented globally.
The level of detail about the energy system limits tactical planning of the energy system. It is not a “bottom-up” model, but instead a more top-down approach to the energy system.
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 1.5%/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
Equity, non-climate environmental, health and other effects are not extensively included. (Air quality was added in September 2020.)
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. This creates the potential for modeling policy impacts inconsistently.
While En-ROADS includes many feedback processes (e.g., carbon fertilization and carbon saturation), it does not yet include the effects of various uncertain biogeochemical feedback processes such as the reinforcing feedback due to a sudden release of methane from permafrost (the user can make adjustments in the Assumptions to add this effect, however).