En-ROADS Model Version History🔗

November 2023 Release🔗

Interface Changes🔗

Improved graph navigation: The graph menu has three new features to make it easier to find and access graphs:
- Grid view — Use the new grid view to visually locate a graph.
- Search — Quickly find the graph you’re looking for by using the new search bar at the top of the graph menu.
- Favorites — Click the star next to any graph to add it to your favorites.
Removed the "Renewables Capacity" and "Nuclear Capacity in Gigawatts" graphs. (These graphs had potential for confusion because they did not display nameplate capacity. More suitable replacements will be considered for a future release.)
Improved the description for the "Long-term economic growth rate" slider to explain the basis for the default value.

Model Upgrade🔗

En-ROADS model to version 23.11.0
Removed model structure and assumptions for COVID-19 impacts.
Updated GDP per capita data through 2022 using the latest 2023 World Bank data.
Corrected the calculations for the share of total capital that is electric, as displayed in the "Electric Share of Total Transport" and "Electric Share of Total Buildings & Industry Equipment" graphs.
Fixed an issue that caused the "Electric Share of Transport Sales" to have unstable behavior or go above 100% in certain scenarios.

October 2023 Release🔗

Interface Changes🔗

Added a "CH₄ Concentration" graph for consistency with C-ROADS.
Renamed the "Electrification policy start year" slider for air and water transport to "Fuel-powered transport sales limit start year" and clarified the slider description.

Model Upgrade🔗

En-ROADS model to version 23.10.0
Improved internal model structure for CCS.

September 2023 Release🔗

Interface Changes🔗

Swahili translation: Additional graph and slider descriptions have been translated into the Swahili language.
Changed the default value for the "DACCS funding start year" slider from 2030 to 2023 (to reflect the fact that direct air capture solutions are already receiving funding).

Model Upgrade🔗

En-ROADS model to version 23.9.0
Fixed an issue where unexpected oscillations were visible in certain graphs with the Renewables slider set to "highly subsidized" and the Carbon Price slider set to a high value.
Fixed an issue where erratic behavior was seen on the "Cost Ratio" graphs when any of the "Reduce new [fossil fuel] infrastructure" sliders were set to 100%.
Fixed an issue where CO₂ emissions were incorrect in scenarios where CCS is encouraged while fossil fuel infrastructure is reduced.

August 2023 Release🔗

Interface Changes🔗

Added a link item to the Help menu that opens the En-ROADS Model Technical Reference.
Updated the name and descriptions of the following two sliders for clarity:
- Adoption of best practices for agriculture (CH₄ & N₂O)
- Adoption of best practices for energy, industry, and waste (CH₄, N₂O, & F-gases)
Changed the default value of the "Effect of temperature on rate of CO₂ and CH₄ emissions from permafrost and clathrates" slider from 0.1% to 0.5% (per year per ºC).
Changed the default value of the "Potential crop yield" slider from 2.5 to 2.8 (times 2020 value by 2100) and adjusted the range slightly to be from 2 to 4 (instead of 1.5 to 3).
Lowered the y-axis maximum on the "Marginal Cost of Low-Carbon Electricity Production" graph to better fit the plots.
Fixed kiosk mode (as used in museums) so that internal links to the Assumptions panel are no longer disabled.

Model Upgrade🔗

En-ROADS model to version 23.8.0
Fixed an issue where the displayed land for BECCS was lower than expected.
Fixed two issues where reducing coal utilization with a carbon price in place created unexpected fluctuations and anomalous price behavior.
Updated various parameters using values from the latest IPCC AR6 report, including greenhouse gas time constants, radiative forcing efficiencies, and global warming potential parameters.
Updated GDP data through 2022 using the latest 2023 World Bank data.
Updated PRIMAP historical emissions data through 2021 with the latest update (v2.4.2, 2023).
Updated NOAA concentration and radiative forcing data through 2022.
Updated GISTEMP and Hadley temperature data through 2022.
Updated NASA sea level rise data through 2022.

June 2023 Release🔗

This update includes major improvements and additions, including a new Baseline Scenario that accounts for the economic impact of climate change; many new sliders and graphs; and model improvements to the land, forests, food, and electrification sectors. Learn more about the update in the articles here.

Interface Changes🔗

Click the arrows to reveal the list of changes.

New graphs added to the simulator

Greenhouse Gas Emissions
- CH₄ Emissions by Source
- N₂O Emissions by Source
CO₂ Emissions
- CO₂ Emissions from Fossil Fuels
- CO₂ Emissions from Coal
- CO₂ Emissions from Oil
- CO₂ Emissions from Natural Gas
- CO₂ Net Emissions from Land Use
- CO₂ Gross Emissions from Forests—Area
- CO₂ Gross Emissions from Forest Bioenergy
- CO₂ Net Emissions from Forest Bioenergy
- Cumulative CO₂ Net Emissions from Forest Bioenergy
Primary Energy Demand—Types
- Bioenergy Primary Energy Demand by Feedstock
Final Energy Consumption—Types
- Electric Share of Transport Sales
- Electric Share of Buildings & Industry Equipment Sales
Land, Forestry, & Food
- Deforestation
- Deforestation and Mature Forest Degradation
- Deforestation and Mature Forest Degradation—Area
- Forest Area
- Forest Area by Age
- Carbon in Forests
- Carbon Density of Forests
- Farmland Area
- Percent of Food from Animals
- Crop Production Needed
- Crop Yield
- Land Harvested for Bioenergy—Area
CO₂ Removals
- CO₂ Removals by Type
- CO₂ Removals from Land
- CO₂ Captured by CCS by Source
Financial
- Cost Ratio of Electric to Oil-Powered Transport
- Cost Ratio of Electric to Fuel-Powered Equipment

Graphs removed from the simulator

Greenhouse Gas Emissions
- Greenhouse Gas Total Emissions
CO₂ Emissions
- CO₂ Emissions
- CO₂ Emissions by Source
Primary Energy Demand Totals
- Sources of CCS Primary Energy
- Electric Energy Capacity including CCS
CO₂ Removals
- Anthropogenic CO₂ Emissions and Removals
- Annual Volume of Captured CO₂
- Cumulative Storage of Captured CO₂

Graph organization and data updates

Edited graph and slider descriptions for clarity.
Reorganized the graph menus to make frequently used graphs easier to access. (For example, the "Impacts" menu has been moved to the top of the list.)
Added section headers to the "CO₂ Emissions" and "Land, Forestry, and Food" graph menus to make the groupings more clear.
Updated the styling of the "Miniature Graphs" view to make plots easier to distinguish.
Updated the “Share your scenario” feature so that a scenario with the Kaya or Mini Graphs view active will open to that view from the shared link.
Adjusted the y-axis maximum on some graphs to display the data better over different input configurations.
Updated historical comparison data from Lazard, IEA, Global Carbon Budget, NOAA, Met Office, and NASA.

Other changes to graphs

Renamed the “Net Carbon Dioxide Removal” graph to “Net Anthropogenic CO₂ Removal.”
Renamed the “Low-Carbon Marginal Cost of Production” graph to “Marginal Cost of Low-Carbon Electricity Production.”
Renamed the “Net CO₂ Emissions” graph to “CO₂ Net Emissions.”
Renamed the “Electric Share of Total Capital—Transport” graph to “Electric Share of Total Transport.”
Renamed the “Electric Share of Total Capital—Buildings & Industry” graph to “Electric Share of Total Buildings & Industry Equipment.”
Renamed the “CO₂ Emissions per Dollar of Real GDP” graph to “CO₂ Emissions per Dollar of GDP.”
Renamed the “Net Cumulative CO₂ Emissions” graph to “Cumulative CO₂ Net Emissions.”
Replaced the “Net Land Use & Forestry Emissions” graph with “CO₂ Net Emissions from Land Use without Bioenergy.”
Replaced the “CO₂ Emissions by Source” graph with “CO₂ Emissions from Energy by Source” graph.
In the “Greenhouse Gas Net Emissions by Gas” graph, replaced “Energy CO₂”, which included bioenergy emissions, with “Fossil Fuel CO₂”, which does not include bioenergy emissions, and moved bioenergy emissions to “Land Use CO₂.”
Changed the damage function formulation options in the “Reduction in GDP vs Temperature” graph.
The “GDP per Capita” and “Gross World Product” graphs now include a “scenario if no economic impact from temp” line.
In the “Net Cumulative CO₂ Removed by Type” and “Sources of Net CO₂ Removals” graphs, renamed “Direct Air Capture” to be “DACCS.”
Removed “CCS Paths” from the “Electric Final Energy Consumption by Source” graph.
Moved the “Global GDP Loss” graph from the Population & GDP section to the Impacts section.

Other interface changes

Added tooltips to the "Temperature Increase in 2100" figures to allow for seeing temperature values out to two decimal places.
Renamed the “Afforestation” advanced view title to “Afforestation and Reforestation.”
Renamed the “Deforestation” advanced view title to “Deforestation and Food.”
Updated the ranges for the Tax/Subsidy sliders.
Assumptions
- Added and removed various options under the Assumptions view to reflect the updated modeling.
- Added category headers in the Assumption view (e.g., "Earth system", "Economy").
- Redesigned the "Economic impact of climate change" section in Assumptions:
  - Added a switch to turn off the damage function.
  - Added a new dropdown selector for choosing from a list of damage function presets.
  - Added a new "Custom" option for providing custom damage function parameters.
  - Changed the literature-based options (added Burke 2018 and Howard & Sterner, removed Nordhaus and Weitzman).
- Added links to specific assumption sliders from various graph descriptions for more direct navigation.

Documentation Updates🔗

En-ROADS User Guide
- Updated explanations in the En-ROADS User Guide based on modeling improvements.
- Updated the “Model Comparison—Historical” section with newer data.
En-ROADS Technical Reference
- Redesigned the En-ROADS Technical Reference with improved navigation and documentation features.
- Updated technical documentation to describe the modeling changes made in this release.

Model Upgrade🔗

En-ROADS model to version 23.6.0
Updated Baseline Scenario: Several model adjustments related to electrification, energy sources, and the inclusion of the economic impact of climate change have lowered the baseline temperature in 2100 to 3.3°C/5.9°F. More details on the Baseline Scenario here.
- Economic growth in the Baseline Scenario is now affected by the economic impact of climate change via a damage function. The damage function in the Baseline Scenario is from Burke et al. 2018. More details on the damage function here.
- Added a global carbon price of $5/ton CO₂ in 2023 based on the current global average from the World Carbon Pricing Database (Dolphin 2022), ramping up linearly from 2016 to 2022 and constant thereafter.
Land, Land Use Change, and Forestry: Added a more detailed model of the terrestrial carbon cycle. The movement of carbon between the atmosphere, biomass, and soil now depends on the type of land and the age of forests, meaning that land use, land use change, and forestry (LULUCF) emissions are calculated endogenously. More details on land here.
- Four land use categories are modeled (forest, farmland, tundra, and other) plus three ages of forest, with the area and amount of carbon in biomass and soil included for each.
- Controls in the Deforestation and Afforestation menus now directly affect changes in land area and carbon stocks.
- Bioenergy now depends on land availability (see below).
- Land use change depends on food and agriculture (see below).
Food and agriculture: Added an explicit model of food demand based on population and GDP per person, which affects the need for farmland. This in turn affects LULUCF (see above) as well as emissions of methane and nitrous oxide. Sliders within the Deforestation menu now control some of the drivers of land use change, such as food waste and food from animals. Sliders within the Methane & Other Gases menu now reflect adoption of lower-emissions practices. More details on food and agriculture here.
- Demand for crops—used for food, animal feed, and energy—along with crop yield, drive the demand for farm area.
- Crop yield is a dynamic function dependent on food needs and economic damage due to climate change.
- Total food demand and demand for animal products (meat, milk, eggs, etc.) increase with increasing GDP, affected by user controls.
Bioenergy: Linked the growth and harvest of fuel for bioenergy into the new terrestrial carbon cycle (see above) and explicitly modeled the regrowth of biomass after harvest. Bioenergy removes biomass from the land, affecting the movement of carbon between the atmosphere, biomass, and soil. Controls in the Bioenergy and Deforestation advanced views can encourage, discourage, or affect the limits on the use of bioenergy. More details on bioenergy here.
- Three bioenergy feedstocks (wood, energy crops, and waste/other) are individually modeled with specific controls for each.
- The cost of bioenergy now depends on the availability of forest and farmland and rises as land and biomass on the land become scarcer.
Electrification: Added details related to the choice between electric and fuel-based transportation, buildings, and industry. Cost, mandates, charging infrastructure (such as charging stations and installation availability) and other factors now interact to determine the rate of adoption of electric vehicles, heat pumps, etc. Controls in the Electrification menus include various kinds of subsidies and mandates. More details on electrification here.
Carbon capture and sequestration (CCS):
- Removed CCS and BECCS sliders, but improved some of the underlying structure for better fit to historical data. Improvements to CCS policy controls are planned for future releases. For now, CCS and BECCS are encouraged by a carbon price unless users choose to switch this setting off.
- Added nonelectric CCS for coal, natural gas, and bioenergy.
Changed the default time to commercialize for New Zero-Carbon energy from 10 years to 20 years.
Removed transmission and distribution (T&D) costs from the marginal cost of electricity for each energy source. T&D costs are included in the decisions between electric and non-electric carriers.

February 2023 Release🔗

Interface Changes🔗

Persian translation: The complete En-ROADS interface is now available in the Persian (Farsi) language.
Changed the main graph menu to a two-column layout for easier navigation.
Improved the layout of advanced views so that more sliders are visible at once.
Fixed an issue where graph data values were sometimes rounded incorrectly when using the "Copy Data to Clipboard" feature.

Model Upgrade🔗

En-ROADS model to version 23.2.0
Updated historical CO₂ fossil fuel emissions data (through 2021) using the latest Global Carbon Budget 2022 dataset.

November 2022 Release🔗

Interface Changes🔗

Changed the start year for input sliders to 2023.
Changed the main sliders to show a "detailed settings active" message (instead of a disabled slider) to make it more clear when a "use detailed settings" switch is enabled.

Model Upgrade🔗

En-ROADS model to version 22.11.0
Updated to the latest WEO data, which includes 2022 scenario projections and historical data through 2020.
Updated historical temperature change data (through 2020) using the latest GISTEMP and HADCRUT datasets.
Updated radiative forcing data used for model calibration.
Corrected an error in GDP data that led to slightly inaccurate historical results.
Corrected the calculation of "Probability of ice-free arctic summer at least once before 2100", which previously produced inaccurate results in certain scenarios.

October 2022 Release🔗

Interface Changes🔗

Updated the units for the sea level rise assumption sliders to be "meters by 2100" instead of "meters."
Fixed an issue that caused some graphs with U.S. unit system variants to be displayed twice in the menu.

Model Upgrade🔗

En-ROADS model to version 22.10.0

September 2022 Release🔗

Interface Changes🔗

Updated the Population slider range to reflect the latest World Population Prospects data from the United Nations.
- The previous range was 9.1 to 13.2 billion, with a baseline value of 10.9 billion.
- The updated range is 8.8 to 12.4 billion, with a baseline value of 10.4 billion.
Adjusted the y-axis ranges on the "CH₄ Emissions" and "N₂O Emissions" graphs.

Model Upgrade🔗

En-ROADS model to version 22.9.0
Updated population (historical and projection) data using the latest 2022 World Population Prospects data from the United Nations.
Updated GDP data (through 2021) using the latest 2022 World Bank data.
Updated WEO data to the latest 2022 data. (In particular, data for WEO 2021 now more clearly defines the allocation of "other energy.")
Updated greenhouse gas concentration data using the latest NOAA data.

August 2022 Release🔗

Interface Changes🔗

Dutch translation: The core En-ROADS interface is now available in Dutch (Nederlands).

July 2022 Release🔗

Interface Changes🔗

Norwegian translation: The complete En-ROADS interface is now available in Norwegian (Norsk Bokmål). The En-ROADS User Guide has been translated into Norwegian as well.
Fixed an issue where En-ROADS would fail to open on certain Windows laptops with unusual screen dimensions.

Model Upgrade🔗

En-ROADS model to version 22.7.0
Fixed an issue where flow to storage was slightly higher than it should be due to an incorrect calculation related to the amount of BECCS carbon removed.

May 2022 Release🔗

Interface Changes🔗

Hindi translation: The core En-ROADS interface is now available in Hindi.
Improved user guide: The En-ROADS User Guide has been revised to include more detail, embedded videos, and a glossary. These improvements are also included in the advanced view help pages within En-ROADS.
Improved the "Related Graph" selector in the "Economic impact of climate change" assumptions panel so that it stays in sync with the selected main graph.
Fixed an issue where En-ROADS would fail to open if a shared scenario refers to a graph that is no longer available.

Model Upgrade🔗

En-ROADS model to version 22.5.0

April 2022 Release🔗

Interface Changes🔗

Hebrew translation: The complete En-ROADS interface is now available in Hebrew.
Italian translation: The En-ROADS User Guide is now available in Italian, and the advanced view help pages in En-ROADS now appear in Italian when it is the selected language.
Spanish overview video: We have added a Spanish version of the "En-ROADS Overview" video, which can be accessed from the Help > Video Tours menu when Español is the selected language.
Updated the description for the "Emissions performance standard" slider to clarify that it affects electricity only.
Improved the Final Energy Consumption graph descriptions to clarify that total energy consumed does not include energy lost through transmission and distribution (T&D) or inefficiencies.

March 2022 Release🔗

Interface Changes🔗

New translations: The core En-ROADS interface is now available in Swahili and Slovenian. Thank you to the volunteer translators who are helping to bring En-ROADS to thousands of users in their native language.
Updated sea level rise projection: The "Sea Level Rise" graph reflects the updated sea level rise projection in En-ROADS, which is now in line with the latest IPCC AR6 report (see "Model Upgrade" notes below). More details of these changes are available in our blog post.
Storm surge mapping: The "Sea Level Rise–Flood Risk Map" now includes a new map type called "21st Century with Storm Surge." This new mode allows users to show the impact of a localized storm on top of global sea level rise.
Added two sliders in the "Sea level rise" group under Assumptions to allow for simulating different ice sheet melting scenarios for Antarctica and Greenland. The "Sea Level Rise–Flood Risk Map" has been updated to take these slider values into account.
Updated the "Population Exposed to Sea Level Rise" graph to use the updated sea level rise projection.
Updated the value of the NDC dot to reflect COP26 announcements. The NDC dot is available by selecting the "Show UN Pledges (NDCs)" option in the "Greenhouse Gas Net Emissions" graph actions menu.
Renamed the "Methane & Other" slider on the main interface to "Methane & Other Gases."
Improved the GDP slider descriptions in the "Economic Growth" advanced view.

Model Upgrade🔗

En-ROADS model to version 22.3.0
Updated the default sea level rise projection in En-ROADS to align with the IPCC Sixth Assessment Report (AR6). En-ROADS now closely matches the AR6 median estimate. This results in a lower default sea level rise projection in 2100. Additionally, two new sliders were added (found under Assumptions) to allow users to explore how the uncertainties of ice sheet melt in Antarctica and Greenland affect global sea level rise.
Corrected an issue where the model behavior for some impacts (e.g., biodiversity loss) caused the Current Scenario value to exceed 100% under some extreme scenarios; these are now capped at 100%.

January 2022 Release🔗

Interface Changes🔗

Added a new slider, "Years to achieve other greenhouse gas targets" in the "Methane & Other Gases" advanced view, to allow for simulating the 2021 Global Methane Pledge.
Changed the start year for input sliders to 2022.
Improved the titles of the miniature graphs for consistency and clarity.
Adjusted the y-axis range on the "Revenue & Cost from Taxes & Subsidies" graph.
Reordered the datasets in the CDR graphs to match the order of the sliders in the "Technological Carbon Removal" view.

Model Upgrade🔗

En-ROADS model to version 22.1.0
Fixed the behavior of economic assumption sliders (e.g., "Plant development time", "Plant construction time", and "Progress ratio") so that they do not affect model outputs in past years.

December 2021 Release🔗

Interface Changes🔗

Russian translation: The core En-ROADS interface is now available in Russian.
Improved sharing of the "UN Pledges" feature. When opening a shared scenario that includes the "Greenhouse Gas Net Emissions" graph, the "All Countries Follow NDCs" bar will be shown if the sender had the feature enabled.
Corrected the types of power plants in the descriptions for the "CCS effectiveness" sliders (found under Assumptions).

Model Upgrade🔗

En-ROADS model to version 21.12.0

November 2021 Release🔗

Interface Changes🔗

UN Pledges: Added a "Show UN Pledges (NDCs)" option to the actions menu for the "Greenhouse Gas Net Emissions" graph. (Click the three vertical dots icon to reveal the menu.) When selected, a red bar will appear on the graph, indicating the approximate level of emissions in 2030 if all countries were to follow their emissions reduction pledges.
Renamed the "Marginal Cost of Renewables–Area" graph to "Marginal Cost of Wind and Solar–Area". The graph description now indicates that the data for "Wind & Solar" includes other renewable sources (which comprise a small percentage of capacity).
Amended the Electrification slider descriptions to state that the Baseline Scenario can contribute to electrification.
Amended the Electrification and Energy Efficiency slider descriptions to state that the action is phased in over 10 years.
Improved the descriptions for the "Electric demand response technology" and "Electric carrier" progress ratio sliders (found under Assumptions).
Improved color contrast on the "Sea Level Rise–Flood Risk Map."
Fixed the Help > En-ROADS User Guide menu item to open the translated version of the User Guide when available (when German is the selected language, for example).

Model Upgrade🔗

En-ROADS model to version 21.11.0
Fixed an issue that caused a mismatch in the Baseline and Current Scenario lines on the "% Electricity Consumption from Qualifying Sources" graph.

October 2021 Release🔗

Interface Changes🔗

Sea level rise maps: Flood risk maps from Climate Central have been integrated into En-ROADS under Graphs > Impacts. These maps display the land areas that are at risk of flooding due to sea level rise, as well as the land that can be saved by actions made in the Current Scenario in En-ROADS. More details of this new feature are available in our blog post.
German translation: The En-ROADS User Guide has been translated into German, and the advanced view help pages in En-ROADS now appear in German when it is the selected language.
Added carbon budget lines to the "Net Cumulative CO₂ Emissions" graph. These lines indicate the level of accumulated CO₂ that is consistent with a 66% chance of hitting either 2°C or 1.5°C. The carbon budget lines have been updated to be consistent with recently released IPCC AR6 values.
Removed the "Cumulative CO₂ Emissions" graph as it is redundant.
Fixed the Actions & Outcomes view to display active policy switches (e.g., "Use clean electricity standard").
Corrected the variables displayed in the "Oil Primary Energy Demand–Area" and "Bioenergy Primary Energy Demand–Area" graphs to match the non-area graphs.

Model Upgrade🔗

En-ROADS model to version 21.10.0
Corrected the behavior of the "Renewable Primary Energy Demand" graph when the CDR maximum for BECCS is set to zero.
Corrected a bump in the economic damage curve when the "Reduction in GDP at 2°C" and "Maximum reduction in GDP" settings were the same.
Fixed an issue where the Social Cost of Carbon value could go negative.
Fixed an issue that caused a spike in the energy demand graphs when "% Reduction in coal/oil/gas utilization" is set to 100% and the "stop year" is set earlier than 2100.

September 2021 Release🔗

Interface Changes🔗

Climate impacts: Five new bar graphs have been added under the Graphs > Impacts menu showing the effects of climate change:
- Population Exposed to Sea Level Rise
- Probability of Ice-free Arctic Summer
- Decrease in Crop Yield from Temperature
- Species Losing More than 50% of Climatic Range
- Additional Deaths from Extreme Heat
Graph actions menu: A new contextual menu is available by clicking the "three dots" icon to the right of a graph title. The menu reveals actions related to the graph:
- Show Description
- View Larger
- View in New Window
- Copy Data to Clipboard
Updated the range for the "Climate sensitivity" slider to match the new AR6 findings from the IPCC.
Revised the description for the "Social discount rate" slider.
Improved handling of scenario links with invalid parameters. When opening a link created with an older version of En-ROADS, if any parameters are no longer valid, a warning will be displayed showing which sliders are affected (instead of resetting the entire scenario).

Model Upgrade🔗

En-ROADS model to version 21.9.0
Fixed the model so that the "HFC phase out start year" slider has an effect only when the "Use detailed settings" switch is active.

August 2021 Release🔗

Interface Changes🔗

Japanese translation: Additional graph and slider descriptions have been translated into Japanese.
To avoid redundancy, air pollution parameters have been consolidated under Assumptions > Air pollution with a single slider for each fuel type. This does not change model behavior.
Adjusted the y-axis range on several graphs to better display their plots.
Matched the y-axis maxima for pairs of graphs that display "Total" and "by Source–Area" information so they are more easily compared.
Improved the descriptions for the "Nuclear R&D breakthrough cost reduction" slider and the Bioenergy view.
Removed a redundant slider for methane leakage from the Natural Gas advanced view. The other slider is found in the Methane & Other Gases advanced view.

Model Upgrade🔗

En-ROADS model to version 21.8.0
Corrected an error in the energy utilization sector which was causing the price of electricity to increase and preventing renewables from growing as they should in the absence of fossil fuel utilization.
Corrected an equation which omitted the hydro-generated energy from the "Renewables" plots in the "Final Energy Consumption" graphs.

July 2021 Release🔗

Interface Changes🔗

Arabic translation: The core En-ROADS interface is now available in Arabic.
COVID-19 impacts: Added a set of eight new sliders (under the Assumptions > COVID-19 impacts heading) for controlling the assumptions about the impacts of the COVID-19 pandemic on greenhouse gas emissions and other model parameters.
Removed the "Average Cost of Electricity Production" and "Low-Carbon Average Cost of Production" graphs. (Utilization in the model no longer depends on average costs, so the marginal cost graphs are more useful.)
Corrected the y-axis range of the "Land for Growing CO₂-Removal Biomass" and "Land for Farming with CO₂ Removal" graphs.

Model Upgrade🔗

En-ROADS model to version 21.7.0
Added structure to model the effects of the COVID-19 pandemic on the global economy, energy demand, and other indicators.

June 2021 Release🔗

Interface Changes🔗

Japanese translation: The core En-ROADS interface is now available in Japanese.
German translation: Additional graph and slider descriptions have been translated into German.
Clean electricity standard: Added new features to the "Carbon Pricing and Energy Standards" advanced view:
- Activate the clean electricity standard policy with a switch and adjust the settings of the policy with multiple new input sliders.
- Control the types of energy sources that qualify for the clean electricity standard.
- New graph "% Electricity Consumption from Qualifying Sources" has been added to the Final Energy Consumption Types group.
Social cost of carbon: Added new table for the social cost of carbon in the Population & GDP group.
Added transport electrification sliders to separate out transport based on land (road and rail) from transport based in air or on water.
Added a link to view more historical graphs in the Model Comparison–Historical group.
Added a new button (on the main view and under the Help menu) that links to the web page for registering your En-ROADS events.
Added a line to compare the trajectory of HFCs with the Kigali Amendment to the Montreal Protocol on the "SF₆, PFC, and HFC Emissions" graph.
Added the "SF₆, PFC, and HFC Emissions" graph to the list of related graphs in the "Methane & Other Gases" advanced view.
Added the version number to the lower right corner of the interface.
Removed "beta" references from the interface.
Reordered graphs in the Model Comparison–Historical group.
Improved graph and slider descriptions.

Model Upgrade🔗

En-ROADS model to version 21.6.0
Note that starting with this release, the model version number is now based on the date of the release (for example, 21.6 refers to the sixth month of 2021).
Added structure for clean electricity standard and social cost of carbon to the En-ROADS model.
Transmission and distribution costs for electricity are now included in the variable costs to produce the electricity.

May 2021 Release🔗

Interface Changes🔗

Translation into French: En-ROADS is now available in French.
Graph replacements: Because of differences in carrier efficiencies, the percent of capital that is electric is not the same as the percent of final energy for that capital. We have therefore changed the associated graphs from "Electric Share of Final Energy" to "Electric Share of Capital" for Buildings & Industry and for Transport.
Rearranged the ordering of the Simulation > Assumptions sliders to follow the relative order of the slider groups on the En-ROADS main view.
Made small text edits to graph and slider descriptions.

Model Upgrade🔗

En-ROADS model to version 2.7.39
Updated data for non-CO₂ GHGs through 2018 using PRIMAP 2.2.

April 2021 Release🔗

Interface Changes🔗

Structural upgrades to the user interface: We have updated the underlying architecture of En-ROADS to allow future feature additions to be added more easily. You will not see any functional differences in the operation of En-ROADS or in the interface layout of En-ROADS. There are some aesthetic improvements and multiple changes that make the simulation easier to operate. User experience improvements include:
- The currently selected graph is indicated in the graph selection menu.
- Sliders and menus work better on a wider variety of touchscreen devices (no more touchscreen warnings).
- The interface is more responsive when resizing the browser window.
- The simulation loads faster.
- The Actions & Outcomes view size adapts to its contents.
- Many other subtle additions that will enhance the usability of the simulation.
New Assumptions slider for social discount rate: We have added a new input slider, "Social discount rate," under the Assumptions > Economic impact of climate change heading. The effect of changes to the social discount rate are displayed in a new graph, "Global GDP Loss" and in the Actions & Outcomes table as "Discounted Cumulative Damage through 2100."
New Assumptions slider for fossil fuel CCS leak rate: We have added a new input slider, "Fossil fuel CCS leak rate," under the Assumptions > Carbon capture & storage (CCS) effectiveness heading. This slider allows the user to test non-zero leak rates for fossil fuel CCS.
New graphs added to the simulation:
- In the Removals and Land Use group:
  - Annual Volume of Captured CO₂
  - Cumulative Storage of CO₂
- GDP-related graphs relocated to the Population & GDP group:
  - Reduction in GDP vs Temperature
  - Reduction in GDP from Climate Impacts
- New GDP-related graphs also under the Population & GDP group:
  - GDP per Capita Growth Rate
  - Global GDP Loss (which also shows the discounted value of economic damage)
Read more in our blog post about climate impacts on GDP.
New historical comparison graphs: There is a new graph menu group, Model Comparison–Historical. These graphs compare historical data to En-ROADS simulation output from 1990-2020.
- Temperature History
- Marginal Cost of Solar Electricity History
- Primary Energy Demand of Coal, Oil, and Gas History
- Primary Energy Demand of Wind and Solar History
- Greenhouse Gas Net Emissions History
Added Spanish translations of graph and slider descriptions.

Model Upgrade🔗

En-ROADS model to version 2.7.38
Added model structure for carbon dioxide removal (CDR), carbon capture and storage (CCS), and economic impact of climate change on GDP.

March 2021 Release🔗

Interface Changes🔗

Translation into Italian: En-ROADS is now available in Italian.
New slider for Economic impact of climate change: A new slider type with two input "handles" has been added to the Assumptions menu: Economic impact of climate change. The two handles control "Reduction in GDP at 2ºC from climate impacts" and "Maximum reduction in GDP."
Two new "Climate impact on GDP" related graphs have been added under the Impacts header:
- Reduction in GDP vs Temperature
- Reduction in GDP from Climate Impacts
Read more in our blog post about the economic impact of climate change in En-ROADS.
Added an Assumptions slider for the progress ratio of electrifying transport, buildings, and industry under Simulation > Assumptions > Progress ratio > Electric carrier.
Improved the colors on the "Renewables Capacity–Area" graph to make the plots easier to distinguish.
Changed the Simulation > Assumptions > Climate sensitivity > "Sea level rise from ice sheet melting" slider label to "Additional sea level rise from ice sheet melt" and edited its associated description text for greater clarity.

Model Upgrade🔗

En-ROADS model to version 2.7.37
Added model structure for economic impact of climate change on GDP.

February 2021 Release🔗

Interface Changes🔗

Four new translations: New translations added for simplified Chinese, traditional Chinese, German, and Bulgarian. More languages on the way in March!
New graphs: New graphs added related to enhanced mineralization and other carbon removal approaches:
- Land for Growing CO₂-Removal Biomass
- Land for Farming with CO₂ Removal
- Bulk Material for Mineralization
For more details about the carbon removal approaches displayed in these new graphs see this related blog post.
Added new assumptions specific to enhanced mineralization (found in Assumptions > Mineralization settings).
Relocated the Language menu to the first menu position and included a globe icon as an indicator for the menu.
Changed terminology from "mid-19th century" to 1850.
Adjusted some graph and slider labels for better fit in translations.

Model Upgrade🔗

En-ROADS model to version 2.7.36
Updated temperature change data and reference years using new temperature data update in HADCRUT5 dataset from December 2020.
Modified En-ROADS to use baseline data from C-ROADS that is fed into the En-ROADS data model for initialization.
Updated profitability effects to avoid getting too large with extremes that were leading to drastic and unrealistic swings that could be seen in capacity, utilization, and pricing.
Used PRIMAP 2.1 data (2019) of historic GHG emissions to update initial fractions of each non-CO₂ GHG emissions from agriculture, waste, extracted fuel supply, demand capital, and non-CO₂ GHG emissions from energy use) and to improve calibration.
Improved and simplified CH₄ concentration calibration to avoid unnecessarily introducing more uncertainty in response to CH₄ concentration effects on uptake and to include updated PRIMAP data.
Resolved unexpected bioenergy demand spikes that had appeared in the previous release for some scenarios.

January 2021 Release🔗

Interface Changes🔗

Translation into Turkish: We have a new translation into Turkish this release. Check it out under the Language menu.
New graph: Added a new graph, "% Electricity Consumption from Low-Carbon Sources". Find it under "Final Energy Consumption Types" under the Graphs menu.
Corrected all references to Purchasing Power Parity to $US 2017.
Made various text edits.

December 2020 Release🔗

Read more details or watch a video overview about the update.

Interface Changes🔗

New default graphs: Changed the default graphs from "Global Sources of Primary Energy" and "Temperature Change" to "Global Sources of Primary Energy–Area" and "Greenhouse Gas Net Emissions".
Added several graphs related to renewable energy:
- "Low Carbon Average Cost of Electricity Production by Source",
- "Low Carbon Marginal Cost of Electricity Production by Source", and
- "Renewables Capacity–Area".
Changed the phrase "Business as usual" and "BAU" to "Baseline" across the interface, graphs, legends and descriptions.
Renamed "New Technology" Energy Supply to "New Zero Carbon" Energy Supply throughout En-ROADS interface.
Changed the population input slider to display "billion people in 2100" instead of the -1 to +1 index range.
Expanded the inputs for Economic Growth from a single input to now include "Long-term economic growth", "Near-term economic growth" and a "Transition time" for the "Near-term economic growth" to converge on the "Long-term economic growth" rate.
Changed the start year for input sliders to 2021.
Updated the ranges for the Tax/Subsidy sliders.
Edited some graph descriptions have for clarity.
Adjusted the Y-axis maximum on some graphs to display the data better over different input configurations.

Model Upgrade🔗

Updated Baseline: Several model adjustments related to renewable energy sources, pre-industrial temperature benchmarking, and modeling of non-greenhouse gas forcings have lowered the baseline temperature in 2100 to 3.6°C/6.5°F.
- Renewables are now disaggregated and explicitly modeled for solar, wind, geothermal, and other renewables.
- We also account for the historical subsidies for renewables and the "soft costs" associated with each renewable type. These soft costs have declined as experience was gained.
- The temperature change reported is now relative to the 19th century.
- Initial heat is now calculated from historic temperature change in 1990, taken from temperature anomaly relative to 19th century from GISS (2020) and Hadley (2020) and adjusted to be relative to 18th century mean.
- Other forcings taken from Meinshausen (2011) to reflect those relative to 18th century. Natural forcings easier to subtract to obtain anthropogenic forcings for Equivalent CO₂ concentration.
- Initial CO₂, CH₄, and N₂O updated to reflect actual data from GISS instead of C-ROADS 1990 values.
- Decrease in extraction overheating sensitivity and profitability effects on retirement rates of supply sources to dampen rapid changes in bioenergy demand.
En-ROADS model to version 2.7.35c

October 2020 Release🔗

Interface Changes🔗

Added a short description at the top of the Assumptions panel to clarify how the sliders behave relative to the "Current" and "Business as Usual" scenarios.
Fixed descriptions of transport electrification sliders to remove mention of ships and airplanes.

Model Upgrade🔗

En-ROADS model to version 2.7.29b
Corrected the "New Tech" plot in the "Marginal Cost of Electricity Production" graph when the "New Technology" advanced sliders are adjusted.

September 2020 Release🔗

In addition to the details listed below, we've made a September 2020 Release Video highlighting the important new features.

Interface Changes🔗

Spanish: En-ROADS is now available in Spanish! We're working to bring En-ROADS to even more languages too.
Air Pollution graphs: There are two new graphs in the "Graphs > Impacts" menu showing Air Pollution (PM2.5 Emissions) from the energy sector. Additionally, sliders were added in the "Assumptions" panel to allow for adjusting the emission factor assumptions.
Changed the population slider units to be on -1 to 1 indexed scale with "status quo" equal to zero.
Fixed the units of the Carbon Price slider to read "$/ton CO₂" instead of "$/ton".
Fixed the Kaya view to show "Carbon Intensity of Final Energy" instead of "Carbon Intensity of Primary Energy".
Fixed the menu bar to make it easier to select sub-menu items on iPad.
Fixed tooltips on iPad so that they disappear automatically.
Fixed alignment of slider handles on iPad.
Fixed full screen layout on iPad so that the menu bar is not obscured by the Safari-provided controls.
Fixed the large graph window to display in the current language (instead of defaulting to English).
Fixed the x-axis labels on Kaya graphs to not overlap on large screens.
Fixed graphs to not show tooltips for years outside the displayed range.
Removed calibration graphs (these will be replaced by improved graphs in an upcoming release).

Model Upgrade🔗

En-ROADS model to version 2.7.29

August 2020 Release🔗

Interface Changes🔗

Portuguese: En-ROADS is now available in Portuguese! Localization to more languages is in progress, and we hope to come to your native language soon.
Initial iPad Support: You can now run En-ROADS on your iPad (in Safari or your preferred browser)! In this release, the user experience is better on iPad models released in the last 3 years. In upcoming releases, we will be working to improve performance and refine the user experience across all iPad models.
Improved performance in a number of areas, so sliders should feel smoother and more responsive (and further improvements are in the works).
When sharing a scenario, the user's preference for Metric vs U.S. Units is captured and remembered in the URL.
Updated the "Carbon Price" slider description to include bioenergy in the list of impacts.
Removed accidental mention of deforestation in the "Other greenhouse gases start year" slider description under "Methane & Other Gases".

July 2020 Release🔗

Interface Changes🔗

Improved email sharing of scenarios by showing a preview of the message to be sent, and allowing for a custom note to be included with the shared scenario.
Changed the welcome screen to direct feedback and questions to support.climateinteractive.org.
Changed the "General FAQs" link under the Help menu to direct to the Knowledge Base on the support site.
Corrected the y-axis of the "Marginal Cost of Electricity Production" graph to adjust dynamically to keep graph lines in view.
Corrected the "Renewables Primary Energy Demand" graph to reflect hydro in addition to renewables.
Improved descriptions for the "Year to stop building new infrastructure" sliders for coal, oil, and natural gas.

May 2020 Release🔗

Interface Changes🔗

Added email sharing of your current scenario under the "Share Your Scenario" menu.
Edited graph and slider descriptions for clarity.

Model Upgrade🔗

En-ROADS model to version 2.7.19
Updated GDP with 2018 World Bank data.

April 2020 Release🔗

Interface Changes🔗

Added link to "Uses for En-ROADS" under the Help menu.
Added separate "Reset Policies" and "Reset Assumptions" items under the "Simulation" menu and changed wording of "Reset" to "Reset Policies & Assumptions."
Added a new variant of the "Land for Carbon Dioxide Removal" graph that shows units in "Million acres" when U.S. Units is selected.
Improved location of icons in the top toolbar to help avoid accidental clicks on the "Reset Policies & Assumptions" icon (formerly, "Reset sliders" tooltip).
Corrected the large graph feature so graphs are sized correctly in the remote window.
Improved the description texts for "Coal carbon capture & storage (CCS) (tax/subsidy)" slider, "Gas carbon capture & storage (CCS) (tax/subsidy)" slider, and the overall description for Nuclear in the advanced views.

Model Upgrade🔗

En-ROADS model to version 2.7.14

March 2020 Release🔗

Along with the details listed below, we've made a March 2020 Release Video highlighting the important feature additions and changes to model behavior.

Interface Changes🔗

Large graph window: You can create a large copy of any of the graphs to use on additional screens or monitors. The graph outputs in the copies remain connected to changes in the control input sliders. These graphs are accessed under the View menu, as "Large Left Graph and "Large Right graph". You may select multiple copies of left or right graphs.
Added "Hydro" data to "Average Cost of Electricity Production" graph and corrected the name of "Renew/Hydro" to Renewables".
Corrected several missing Related Graphs in some advanced views.
Corrected the variable in the "Marginal Cost of Renewables" graph.
Corrected a typo in descriptions for N₂O and CH₄ graphs (Megatons was corrected to 1x10⁶).
Corrected the y-axis label in the "CO₂ Emissions" graph to show Gigatons CO₂/year.
Edited the description for the "CH₄ Emissions" graph and corrected the plotted variable to display anthropogenic CH₄ emissions.
Edited the "Storage Costs" graph description for clarity.
Edited the description for the "Cumulative CO₂ Emissions" graph.
Changed the graph name from "Fuel Production Cost" to "Fuel Production Cost by Source" to make it consistent with the titles of the other graphs in the Financial category that are broken out by energy source.
Added "Greenhouse Gas Net Emissions by Gas–Area" to related graphs for Deforestation.
Updated the New Tech slider description to match what the slider settings do.
Restored a missing description for the "Coal CCS R&D breakthrough cost reduction" slider.
Edited the description for the "% Reduction in Coal Utilization" slider.
Edited slider names referring to final carbon price, removing the word "target" so it is now:
- Final carbon price (previously, Final Carbon price final target)
- Year to start achieving final carbon price (previously, Year to start achieving final carbon price target)
- Years to achieve final carbon price (previously, Years to achieve final carbon price target)
Restored assumptions sliders for "Methane emissions from biological activity", "Effect of temperature on methane emissions from permafrost and clathrates", and "Temperature threshold for permafrost and clathrates".

Model Upgrade🔗

En-ROADS model to version 2.7.11
Updated the equation for the Energy Intensity of New Capital to better respond to price effects.
Adjusted the BAU improvement rate in emission intensity and Annual improvement rate of emission intensity for F-gases to reflect SSP2 baseline trajectories.
Updated the settings for CH₄ and N₂O emissions from agriculture and waste.

Glossary