DOI: 10.5281/zenodo.7545157
title: FaIR calibration data

description: This dataset contains the full data, input scripts and produced output data for the AR6-consistent calibration of FaIRv2.1.0. The calibration version is also tagged (v1.0) should an alternative calibration strategy for this FaIR version and constraint set be modified in the future. The zipfile contains everything, allowing you to reproduce the workflow. The CSV file is the output most people will probably care about, containing the constrained, calibrated parameter set. <strong>FaIR v2.1.0</strong> Obtainable from https://pypi.org/project/fair/ From the command line: <pre><code>pip install fair==2.1.0</code></pre> <strong>Calibration v1.0</strong> 1.5 million prior ensemble Climate response calibrated on 49 abrupt-4xCO2 experiments from CMIP6 and sampled using correlated kernel density estimates Methane lifetime calibrated on 4 AerChemMIP experiments for 1850 and 2014 (Thornhill et al. 2021a, 2021b). Unlike other variables which are sampled around some prior uncertainty, only the best estimate historical calibration is used. Carbon cycle uses the parameters from Leach et al. 2021 calibrated for FaIR 2.0.0 using 11 C4MIP models. Aerosol cloud interactions depend on SO2, BC and OC, using calibrations from Smith et al. 2021a (developed for AR6) using 11 RFMIP and AerChemMIP models, with a prior of -2 to 0 W/m2. Aerosol radiation interactions use prior values from AR6 Ch6, with a factor of two uncertainty for each species and a prior in the range of -0.6 to 0.0. Ozone uses the same coefficeints as AR6 (Smith et al. 2021b).<br> Effective radaitive forcing uncertainty follows the distributions in AR6. <strong>AR6-consistent constraints</strong> 1001-member posterior (deliberately chosen). Emissions and concentrations from RCMIP (i.e. based on CMIP6) Temperature from AR6 WG1 (1850-2020, mean of 4 datasets), constrained using ssp245 projections beyond 2014. ssp245 projections for 2081-2100. Ocean heat content from AR6 WG1 (1971-2018), linear. two step constraining procedure used: first RMSE of less than 0.16K, then 6-variable distribution fitting. Aerosol ERF, ERFari and ERFaci as in AR6 WG1 <strong>Performance relative to AR6 assessed ranges</strong> <strong>Absolute values</strong> <strong>Relative difference w.r.t. AR6</strong> <strong>Metric</strong> lower central upper lower central upper ECS 2.00 3.08 5.00 0% 3% 0% TCRE* 1.45 1.73 2.08 45% 5% -9% TCR 1.32 1.84 2.45 10% 2% 2% GSAT 1995-2014 rel. 1850-1900 0.71 0.85 0.99 6% 0% 1% OHC 2018 rel. 1971* 331.13 401.52 469.45 1% 1% 1% ERFaer 2005-2014 rel. 1750 -1.99 -1.35 -0.57 -1% 4% -5% WMGHG ERF 2019 rel. 1750 3.07 3.34 3.62 1% 1% 0% Methane ERF 2019 rel. 1750 0.45 0.55 0.66 5% 2% 2% AF 2xCO2* 0.50 0.51 0.53 6% -3% -11% AF 4xCO2* 0.54 0.59 0.63 9% -1% -10% SSP119 2021-2040 rel. 1995-2014 0.37 0.62 0.88 -2% 2% 4% SSP119 2041-2060 rel. 1995-2014 0.37 0.73 1.17 -8% 2% 9% SSP119 2081-2100 rel. 1995-2014 0.20 0.60 1.19 -18% 7% 24% SSP126 2021-2040 rel. 1995-2014 0.40 0.64 0.90 -2% 2% 1% SSP126 2041-2060 rel. 1995-2014 0.54 0.91 1.34 -1% 3% 2% SSP126 2081-2100 rel. 1995-2014 0.49 0.95 1.60 -5% 6% 8% SSP245 2021-2040 rel. 1995-2014 0.46 0.66 0.90 4% 0% 0% SSP245 2041-2060 rel. 1995-2014 0.79 1.13 1.55 1% 1% -2% SSP245 2081-2100 rel. 1995-2014 1.24 1.83 2.63 0% 1% 2% SSP370 2021-2040 rel. 1995-2014 0.47 0.66 0.88 5% -2% -4% SSP370 2041-2060 rel. 1995-2014 0.93 1.25 1.63 1% -2% -7% SSP370 2081-2100 rel. 1995-2014 2.00 2.68 3.54 0% -3% -5% SSP585 2021-2040 rel. 1995-2014 0.52 0.74 1.01 2% -2% -3% SSP585 2041-2060 rel. 1995-2014 1.08 1.51 2.03 0% -2% -3% SSP585 2081-2100 rel. 1995-2014 2.55 3.53 4.75 4% 1% -1% *likely (66%) ranges, otherwise very likely (90%) ranges. <strong>References</strong> Leach et al. 2021: https://doi.org/10.5194/gmd-14-3007-2021 Smith et al. 2021a: https://doi.org/10.1029/2020JD033622 Smith et al. 2021b: https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_FGD_Chapter07_SM.pdf Thornhill et al. 2021a: https://doi.org/10.5194/acp-21-853-2021 Thornhill et al. 2021b: https://doi.org/10.5194/acp-21-1105-2021