Intermediate release of Core Model Proposals:

• 399: Updating the SSP Database (v3.0) including Population, GDP, and Labor Force

New features include the following. For details see the updates page on our documentation site.

1. Forestry details: Hardwood/Softwood and product pools for Pulp and Sawnwood
2. Hydrogen Update
3. Ammonia Trade
4. Biomass Oil Sharing Bugfix
5. Pulp and Paper Detailed Industry
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 v3.2.0
11. Final Bugfix before GCAM 7.1

New features include the following. For details see the updates page on our documentation site.

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

New features include:

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.

New features include:

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

New features include:

• Update final calibration year to 2015
• GCAM has been renamed to the "Global Change Analysis Model".
• Livestock trade has been updated to use an Armington-style approach, instead of fixing trade at historic values.
• A number of bug fixes (e.g., a correction to the MAC technical change) and minor enhancements (e.g., adding the stop-year capability)

New features include:

• Regional agriculture Markets
• Resource - Reserve approach for fossil resource production
• Constraining water markets
• GCAM-USA overhaul
• Bug fixes
• Near-term emissions trend updates

Please see the documentation on Getting started running GCAM for more information on getting started running GCAM. For most users they can download the Mac or Windows Release Package which contain everything they need to run the model and query results. Users who need to compile the model or change the XML input files should consult the documentation.

Bugfix re-release of GCAM 5.1 including the fixes:

• Compatibility with the latest readr and dplyr R packages
• Prevent shifting results when supply / demand curves are enabled
• Fix not properly parsing of some variables which may be needed in the future
• Fix linear-control function to ensure the proper coefficients are being used

GCAM 5.1.2 addresses some issues with GCAM 5.1 including small bugs as well as significantly reduces memory requirements. All users running GCAM 5.1 are encouraged to update to this release.

Bugfix re-release of GCAM 5.1 including the fixes:

• Ensure proper model behavior when compiled with GCC 7+