The En-ROADS Baseline Scenario represents the state of the world if societal and technological changes were to continue at their current rate of progress, without additional policies or action.
The Baseline Scenario does not assume national (e.g., NDCs), sub-national, or corporate climate goals are achieved, as history, unfortunately, shows entities frequently fall short of their targets.
In the landscape of global energy-land-climate model scenarios, the En-ROADS Baseline Scenario is now most comparable to the NGFS Current Policies Scenario produced by three large Integrated Assessment Models and used in the IPCC reports.
The En-ROADS Baseline scenario was created as a reasonable starting point of minimal climate action from which to test various changes in policies and assumptions to see the impacts on our global climate. It helps us understand what the world might look like in the future in the absence of efforts to mitigate climate change. It is not a prediction of the most likely future or an assessment of near-term policy action. The Baseline Scenario represents the state of the world if societal and technological changes were to continue at their current rate of progress, without additional policies or action.
The Baseline Scenario includes an approximate, aggregated implementation of current global technological, policy, and investment conditions. Climate policies in place around the world today, such as the United States’ Inflation Reduction Act and China’s “1+N” framework, are promoting renewables, continuing to subsidize oil and gas, and incentivizing energy efficiency and electrification. En-ROADS does not explicitly represent local, national, international, and corporate policies, but instead estimates the overall effects of the conditions they create. The Baseline Scenario assumes that such conditions will continue, but they do not strengthen or weaken.
What is NOT included in the En-ROADS Baseline scenario?
The En-ROADS Baseline scenario is not intended to capture current policy targets. It does not include national or corporate net-zero emissions pledges, for instance. It also does not include countries’ Nationally Determined Contributions (NDCs) under the Paris Agreement or long term continuation of other national policies. This is an important distinction from some other models’ baseline or “stated policies” scenarios.
We chose to construct the En-ROADS Baseline scenario in this way because “pledged” or “announced” policies can be altered or never be implemented. Governments change and priorities shift. As a result, you can use En-ROADS yourself to compare the globally averaged effects of NDCs to your scenario and Baseline scenario in which those policy actions are not taken. Learn more here: Does the En-ROADS Baseline scenario include countries' future policies or NDCs under the Paris Agreement?
Comparison to other modeling teams’ scenarios
A key procedure in testing our simulators involves comparing their results with other models, particularly the Integrated Assessment Models (IAMs) used by the Intergovernmental Panel on Climate Change (IPCC). IAMs aid scientists and policymakers in understanding climate change dynamics and human impact. By comparing against standardized scenarios used by IAMs, we test assumptions and build confidence that the simulator’s results reflect the best understanding of the scientific literature.
In the landscape of global energy-land-climate model scenarios, the En-ROADS Baseline Scenario is now most comparable to the NGFS Current Policies Scenario produced by three large Integrated Assessment Models and used in the IPCC reports. Whereas previously the En-ROADS Baseline Scenario was calibrated to a no-climate-policy scenario from the Shared Socioeconomic Pathways (the SSP2 Baseline), the 2023 version of En-ROADS is now compared to a newer set of standardized scenarios created by the Network for Greening the Financial System (NGFS).
The NGFS is an international consortium of central banks and financial institutions, and their scenarios contributed to the most recent IPCC Assessment Report (AR6 2022). The NGFS Current Policies Scenario assumes that the only policies that continue into the future are policies that were implemented around the end of 2019. This is similar to the assumptions in the En-ROADS Baseline Scenario, making it a useful comparison. Three different integrated assessment modeling teams contributed to the NGFS scenarios and generated their own versions of the NGFS Current Policies Scenario.
The graph below compares greenhouse gas emissions in the En-ROADS Baseline Scenario to the three IAMs that evaluated the NGFS Current Policies Scenario. The En-ROADS Baseline Scenario uses different assumptions than the IAMs—for example, population in the En-ROADS Baseline Scenario is higher because it follows United Nations population projections, and the carbon prices in the NGFS Current Policies Scenario grow higher than the carbon price in the En-ROADS Baseline Scenario. The variation between the En-ROADS Baseline Scenario and the IAMs producing the NGFS Current Policies Scenario is similar to the variation among the IAMs themselves within the NGFS Current Policies Scenario.
The IPCC’s Sixth Assessment Synthesis Report (2023) gives a range of greenhouse gas emissions for implemented policy scenarios, which include the NGFS Current Policies Scenario (graph below). In terms of global net greenhouse gas emissions, the En-ROADS Baseline Scenario is at the higher end of the range of scenarios in the “Implemented Policies” category due to differences in assumptions about the cascading effects of policies and model dynamics.
Changes to the En-ROADS Baseline Scenario
We routinely update En-ROADS as new science and data become clear and vetted. Occasionally this involved changes to the Baseline Scenario itself. There was a significant update to the Baseline Scenario in June 2023 which is documented here.
What if I disagree with some of the assumptions in the En-ROADS Baseline scenario?
Researchers draw different conclusions about the underlying parameters that compose baseline scenarios. We encourage curious users to vary the assumptions in En-ROADS under the Assumptions menu. There you can change factors tied to the climate, economy, land use, and energy system to explore how sensitive the model is to their changes. We picked one set of assumptions to be our default in the En-ROADS Baseline Scenario, but users can select a different suite of assumptions as a starting point, and then test policies and engage their audiences from there. The assumptions can be accessed by clicking on Simulation in the top menu bar of En-ROADS and selecting Assumptions.
Further information can be found in the En-ROADS Technical Reference.