Recent updates

GCAM v8.5

• GCAM Bugfix Fall 2025

GCAM v8.4

• Socioeconomic and Macro Data Updates

GCAM v8.3

• Gcamstr: A String Interning Implemention in GCAM

GCAM v8.2

• Miscellaneous Bugfixes Prior to 2025 Annual Meeting

GCAM v8.1

• Ukraine as an independent region

GCAM v8.0

• Base Year Update: Move Model Base Year to 2021

GCAM v7.4

• Base Year Update: Initial updates preparing for the new base year

GCAM v7.3

• Updated approach for intermittent electricity integration

GCAM v7.2

• Updating the SSP Database (v3.0)

GCAM v7.1

1. Adding detail to Forest sectors in GCAM
2. Hydrogen Update
3. Ammonia Trade
4. Biomass Oil Sharing Bugfix
5. Pulp and paper industry in GCAM linked explicitly to forest cover
6. AgLU Paramater Updates
7. Food Processing Detailed Industry
8. Residential Floorspace and Energy Demands by Income Decline
9. Agriculture and Food Storage
10. Hector v3.2
11. Final Bugfix before GCAM 7.1

GCAM v7.0

1. Fix Extrapolation in Residue Biomass
2. Add Land Use History Output
3. Miscellaneous Bug Fixes Part 1
4. Add Exogenous Shutdown Decider
5. Miscellaneous Bug Fixes Part 2
6. GCAM v6.0 transportation bugfix
7. Adding fugitive CO2 emissions from fossil resources
8. AgLU data and method updates (connecting land hectares to food calories)
9. GCAM-USA nonCO2 GHG emissions in industrial and urban processes
10. Detailed Natural Gas Trade
11. Natural Gas Final Grade Cost and Miscellaneous Solution Improvements
12. Global Iron and Steel Trade
13. GCAM Macro-Economic Module (KLEM Version)
14. gcamdata chunk re-name
15. Update to Hector v3
16. Bugfix before 7.0 Release

GCAM v6.0 :

1. A new residential floorspace expansion model.
2. Bio-energy updates: additional limits to “unsustainable” deployment
3. Default hotelling rate for climate stabilization scenarios is now 3%.
4. Split out 6 detailed industrial sectors from the aggregate industry sector.
5. Updated Hydrogen production, distribution, and end-use technologies.
6. A new protected lands definition.
7. Expanded crop commodities.
8. Use spatially explicit soil and vegetation carbon data from Moirai.
9. HFC MAC curve fixes.
10. New pollutant emissions controls.
11. Add direct air capture as a mitigation option in GCAM-USA.
12. Gross electricity trade in GCAM-USA.
13. Add GHGs to GCAM-USA.
14. Add pollutant emissions to GCAM-USA.
15. Solution improvements, particularly related to water markets.
16. Change the XML parser library to RapidXML.
17. Add the ability to exit the model early due to solution failure.
18. Reduce memory usage (offsets additional memory from expanded crop commodities).
19. gcamdata: Renv and user modification chunks.

GCAM v5.4:

Several changes have been made to GCAM since the last release version (v5.3). The key updates are:

1. Updated technology costs for electricity and transportation technologies
2. Emissions: using CEDS as data source, updated to 2015, new MAC curves
3. Trade: improved trade for fossil fuels, forestry, and agriculture
4. Included water markets in GCAM-USA
5. Energy for water
6. New food demand representation
7. Solver improvements and library changes
8. gcamdata updated to use drake and work with dplyr 1.0.0
9. Removed unused code
10. Minor updates and bugfixes
11. Optional features (not turned on by default):
    - Direct Air Capture
    - Ability to specify exogenous floorspace pathways
    - Ability to scale CH₄ and N₂O emissions to EPA inventories