CarbonBench | AI4Carbon

The CarbonBench dataset is a benchmark for machine learning emulators of atmospheric CO₂ tracer transport. It was introduced in
Benson et al. (2024): Atmospheric Transport Modeling of CO₂ with Neural Networks.

GitHub Repository

vitusbenson/carbonbench

Official implementation and tools for the CarbonBench dataset - a benchmark for machine learning emulators of atmospheric CO₂ tracer transport.

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Dataset Contents

The dataset contains 3D CO₂ concentrations together with meteorological drivers and flux fields.
All variables are provided as Zarr arrays chunked per timestep.

Variable	Description	Units
`co2massmix`	CO₂ mass mixing ratio	10⁻⁶ kgCO₂ / kgDryAir
`airmass`	Dry air mass	Pg dry air
`gph_bottom`	Geopotential height at lower level	km
`gph_top`	Geopotential height at upper level	km
`p_bottom`	Pressure at lower level	hPa
`p_top`	Pressure at upper level	hPa
`q`	Specific humidity	kg/kg
`t`	Air temperature	K
`u`	Zonal (eastward) wind speed	m/s
`v`	Meridional (northward) wind speed	m/s
`co2flux_anthro`	Anthropogenic surface CO₂ flux	kg CO₂ m⁻² s⁻¹
`co2flux_land`	Land biosphere surface CO₂ flux	kg CO₂ m⁻² s⁻¹
`co2flux_ocean`	Ocean surface CO₂ flux	kg CO₂ m⁻² s⁻¹
`blh`	Planetary boundary layer thickness	m
`tisr`	Incoming solar radiation	J m⁻²
`cell_area`	Surface grid-cell area	m²
`orography`	Surface geopotential	m²/s²

Output variable:

co2massmix at the next timestep (same unit as input)

Baseline Model Results

Performance of the baseline emulators trained on CarbonBench:

Model	Parameters (M)	Decorrelation Time	R²	RMSE
UNet	9.6	>90	0.98	0.52
GraphCast	5.2	>90	0.96	0.86
SFNO	35.7	>90	0.98	0.58
SwinTransformer	37.9	>90	0.99	0.34

Downloading & Preparing the Dataset

You can build the dataset locally using the CarbonBench tools:

# Clone the repo
git clone https://github.com/vitusbenson/carbonbench.git
git clone https://github.com/vitusbenson/neural_transport.git
cd carbonbench

# Install requirements (including neural_transport)
pip install -e ../neural_transport

# Create CarbonTracker-based dataset (example LowRes)
python data/create_carbontracker_dataset.py \
  --save_dir /path/to/data \
  --gridname "latlon5.625" \
  --vertical_levels "l10" \
  --freq "6h"

# Create ObsPack evaluation dataset
python data/create_obspack_dataset.py \
  --save_dir /path/to/data \
  --freq "3h"

Citation

@article{benson2024neuraltransport,
  title = {Atmospheric Transport Modeling of CO2 with Neural Networks},
  author = {Benson, Vitus and Bastos, Ana and Reimers, Christian and Winkler, Alexander J. and Yang, Fanny and Reichstein, Markus},
  year = {2025},
  pages = {e2024MS004655},
  journal = {Journal of Advances in Modeling Earth Systems},
  volume = {17},
  number = {2},
  publisher = {Wiley Online Library},
  url = {https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024MS004655},
}