Key points:

- The ranges of the En-ROADS sliders are not equivalent between sliders.

- We selected the ranges of the sliders to reflect a distribution of possible policy proposals, but it is somewhat subjective.

- The difficulty of taking these actions in the real world is not equivalent between sliders.

How do I learn more about the slider settings?

The En-ROADS User Guide contains information about the ranges of each En-ROADS slider in the “Slider Settings” sections for each slider. The full User Guide can be accessed here: https://docs.climateinteractive.org/projects/en-roads/en/latest/ or you can access the User Guide section for each slider in the advanced settings of that slider by clicking the three dots next to the slider’s name and then the ⓘ button on the top right of the advanced settings panel:

On the left side of the En-ROADS control panel, you can find the energy supply sliders: coal, oil, natural gas, bioenergy, renewables, nuclear, and new zero-carbon energy. 

New zero-carbon energy is explained below. For the other energy supply sliders, each slider is divided up into input levels, e.g., “encouraged,” “discouraged,” and “highly discouraged.”

Examples:

Coal slider settings

The New Zero-Carbon Energy slider has a unique range.

The New Zero-Carbon energy slider has different settings. It can be set to “Breakthrough” or “Huge Breakthrough.” The “Breakthrough” input level means that the new zero-carbon energy source is initially twice the price as coal when it becomes commercially available. The “Huge Breakthrough” input level means that the new zero-carbon energy source is initially the same price as coal when it becomes commercially available. Coal is very cheap compared to all other energy sources except for wind and solar, which have dropped significantly in cost in recent years. You can compare the cost of electricity production from different energy sources in the “Marginal Cost of Electricity Production” graph in the Financial graph category.

Example: New Zero-Carbon set to "Breakthrough" (scenario here)

The ranges of other sliders are not equivalent to each other.

The other sliders in En-ROADS have unique ranges, and the ranges are not equivalent between sliders. For example, the maximum range of the Carbon Price slider is $250 per ton CO₂, which is equivalent to a tax on coal of $660 per ton of coal. The maximum range of the main “Coal price adjustment (taxes minus subsidies)” slider is a 200% net tax on coal, which equates to about $150 per ton of coal (view the “Price of Coal” graph to see the price after taxes and subsidies, and subtract the price at the mine). So the Carbon Price slider has a greater range of impact on the cost of coal than the “Coal price adjustment” slider.

The difficulty of taking these actions is not necessarily equivalent.

Similarly, the difficulties of implementing the policies of each slider are not equivalent. That is, implementing the maximum (or minimum) values of each slider does not present an equivalent degree of difficulty to enact in the world. For example, reducing deforestation by 10% a year (moving the Deforestation slider to “highly reduced”) is not necessarily as difficult in terms of money, political will, or societal change as moving the Transport Electrification slider to its maximum (subsidizing 50% of transport purchase cost and building associated charging infrastructure). 

Sliders affect other parts of the system.

Think of the sliders at the bottom of En-ROADS as a control panel, and the graphs up top as a display of what’s going on in the system. When you move a slider, it will have ripple effects across the whole system, including affecting the result of other sliders that you can move.

For example, if you implement a carbon price, you’ll notice in the graphs that the energy intensity of the economy declines, even though the energy efficiency sliders were not moved. See this scenario in En-ROADS.

En-ROADS is a dynamic model of a whole system: an action in one sector (increasing the carbon price) will cause changes in another sector (energy efficiency of the economy). Just like in the real world, a carbon price will increase the cost of energy unless all energy comes from non-polluting sources, incentivizing people to reduce the amount of energy they use.

If you also move the Transport and Buildings & Industry Energy Efficiency sliders in this scenario, this will cause additional reductions in energy intensity. See this scenario in En-ROADS.

What if the sliders have overlapping effects?

Sometimes when you move a slider, it does not have as much of an effect as you might expect, because it overlaps with other actions that you’ve already taken. For example, if you have already added a carbon price in your scenario, and then you add a tax on coal, you will not see as much of an impact as you would if you just added the tax on coal. The carbon price already did a lot to discourage coal use.

For a summary of this phenomenon, watch this video:

"Why slider sequence matters in En-ROADS"

We selected the ranges of the sliders to reflect a distribution of possible policy proposals, and we acknowledge that some policy proposals may be outside the range of the sliders.