The December 2020 update to C-ROADS includes three significant changes to the modeling and interface of the simulator:
1. A new Baseline Scenario (renamed from “Business as Usual”), which leads to a lower global temperature in 2100 — 3.6°C (6.5°F) instead of 4.1°C (7.3°F). This change arises from:
- Change in the definition of the pre-industrial temperature benchmark. The temperature change in C-ROADS was previously relative to the mid-1700s (to match the approach of other models), and now it is relative to the mid-1800s, a more common time period used in climate policy.
- Improved modeling of non-greenhouse gas forcings, which include those from aerosols (black carbon, organic carbon, sulfates, nitrates, and biomass burning-related), cloud albedo, stratospheric ozone, tropospheric ozone, stratospheric water vapor from methane oxidation, land use, black carbon on snow, volcanic stratospheric aerosol, solar irradiance, and direct forcings from mineral dust aerosol.
- An assessment of the global growth in renewable energy in the En-ROADS simulator resulted in greenhouse emissions reductions being apportioned across regions in C-ROADS.
For more information about the baseline update, please review this technical blog post (the En-ROADS and C-ROADS simulators are rooted in the same baseline modeling) and the C-ROADS Reference Guide.
2. GDP Updates to Modeling:
- Updated last GDP historic year from 2018 to 2019, now measured in $2017 PPP from $2011 PPP.
- Change in long term GDP per capita rate from 1%/year to 1.5%/year, with decreased convergence time.
- Greenhouse gas emissions per GDP parameters adjusted to better reflect recent trends and updated projections in energy and land use.
3. Renaming “C-ROADS World Climate” to simply “C-ROADS” and retiring other versions of the simulator, including C-ROADS Pro and C-Learn.
These new changes are live in the online version of C-ROADS, and will automatically download and update in the background of the Mac or Windows version. Launch the application and leave it running for about five minutes (depending on your Internet connection), and then restart the application. You can verify that your version of C-ROADS is up to date (1.2.6) by checking the “Help” menu.