Update land conversion cost calibration for cropland - FAO as target data set

[flohump]

🐦 Description of this PR 🐦

• scripts land conversion cost calibration for cropland - FAO as target data set instead of MAgPIEown
• default.cfg settings for land conversion cost calibration updated

The file f39_calib.csv now includes meta information on the settings used for generating the calibration factors:

🔧 Checklist for PR creator 🔧

• Label pull request from the label list.

  • Low risk: Simple bugfixes (missing files, updated documentation, typos) or changes in start or output scripts
  • Medium risk: Uncritical changes in the model core (e.g. moderate modifications in non-default realizations)
  • High risk: Critical changes in model core or default settings (e.g. changing a model default or adjusting a core mechanic in the model)

• Self-review own code

  • No hard coded numbers and cluster/country/region names.
  • The new code doesn't contain declared but unused parameters or variables.
  • magpie4 R library has been updated accordingly and backwards compatible where necessary.
  • scenario_config.csv has been updated accordingly (important if default.cfg has been updated)

• Document changes

  • Add changes to CHANGELOG.md
  • Where relevant, put In-code documentation comments
  • Properly address updates in interfaces in the module documentations
  • run goxygen::goxygen() and verify the modified code is properly documented

• Perform test runs

  • Low risk:
    • Run a compilation check via Rscript start.R --> "compilation check"
  • Medium risk:
    • Run test runs via Rscript start.R --> "test runs"
    • Check logs for errors/warnings
  • High risk:
    • Run test runs via Rscript start.R --> "test runs"
    • Check logs for errors/warnings
    • Default run from the PR target branch for comparison
    • Provide relevant comparison plots (land-use, emissions, food prices, land-use intensity,...)

📉 Performance changes 📈

• Current develop branch default : 28.8 mins
• This PR's default : 26.5 mins

🚨 Checklist for reviewer 🚨

• PR is labeled correctly
• Code changes look reasonable
  • No hard coded numbers and cluster/country/region names.
  • No unnecessary increase in module interfaces
  • model behavior/performance is satisfactory.
• Changes are properly documented
  • CHANGELOG is updated correctly
  • Updates in interfaces have been properly addressed in the module documentations
  • In-code documentation looks appropriate
• content review done (at least 1)
• RSE review done (at least 1)

[pvjeetze]

Thanks for these great improvements. Adding the calibration settings to the calib file is also really nice!

I only have some questions of understanding.

[pvjeetze]

Could you briefly explain why the settings have changed here?

E.g. why is it safe to only have a maximum of 20 iterations instead of 40? Can we be sure that under most circumstances the calibration will have finished?

Same goes with other settings, for example the calib_max and calib_min settings.

[flohump]

I revised the calculation of cropland reduction for the reward.
Previously, this was one factor for the whole period 1995-2015.
Now this is calcuated annually, which allows to choose the reward much more targeted than before.
Also, there are less jumps in the reward between the iterations. Therefore, I set the lowpass filter to zero.
I made tests with 20 and 40 iterations. The calib factors don't change much after 20 iterations. Also, the model results are very similar.

[flohump]

The range of calib_min and calib_max was 0.05-3 before.
To avoid very low or very high land conversion costs that avoid any land-use change I reduced the range to 0.2-2.5.
I also tested with 0.2-2. But in this case, we see an implausible strong increase of cropland in IND.

[pvjeetze]

Really nice that you added the switch here!