Current fossil fuel subsidies are included in the En-ROADS Baseline scenario, and you can remove them by moving the coal, oil, and natural gas sliders to "taxed."
“Taxing” here implies the removal of these subsidies by increasing the cost. In En-ROADS, we use the word “tax” to encompass any action making the energy source more expensive. This does not necessarily have to be a direct government tax; it could include such things as divestment movements, private sector decisions, removal of subsidies, etc.
Fossil fuel subsidies are government actions that lower the price of fossil fuels, for instance by lowering the price paid by consumers or decreasing the cost of producing fossil fuels. The estimates for current subsidies are large and varied, making it difficult for us to have confidence in accurately including them explicitly in En-ROADS at the moment.
For instance, the International Monetary Fund (IMF) estimated yearly fossil fuel subsidies at $5.3 trillion/year, while the Organization for Economic Cooperation and Development (OECD) estimated at least $373 - $473 billion in 2015. The OECD analysis did not include subsidies to electricity produced from fossil fuels (which the International Energy Agency (IEA) estimates are $100 billion for 2015) or credit supports and other indirect measures that allow fossil fuels to access financing more easily. For more on this issue, see this Carbon Brief article: https://www.carbonbrief.org/explainer-the-challenge-of-defining-fossil-fuel-subsidies