Global carbon budget terms with sinks partitioned by atmospheric O2
Data files
Sep 30, 2026 version files 7.35 KB
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global_terms.csv
2.68 KB
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README.md
4.67 KB
Abstract
This dataset provides the major terms in the atmospheric budgets for CO2 and O2 as 10-year averages. This is the result of an analysis by Morgan et al. (2026, Science, using the trend in atmospheric O2 and CO2 to constrain the global net land and ocean sinks for CO2. The other input terms to the budget calculation are also provided as a running decadal mean. The atmospheric O2-based approach takes as input the trends in atmospheric d(O2/N2) and CO2, fossil fuel emissions, metal production statistics for iron, aluminum, and copper, ocean heat content, and the cement carbonation sink. One can then solve for the ocean sink, and then determine the net land sink (including emissions from land use change and land use) by difference. Due to uncertainty in the annual mean air-sea exchange of O2, we average over 10-year periods. For full details, see Morgan et al., 2026.
Dataset DOI: 10.5061/dryad.prr4xgz33
Description of the data and file structure
This dataset provides the global net land and ocean sinks for CO2, as derived from the atmospheric O2-based constraint detailed in Morgan, et al. (2026), Science. Data is available as a single csv file, with decadal estimates of net land and ocean sinks for overlapping 10-year periods. Each decadal average is the mean annual flux for a given 10-year period. A 1 sigma uncertainty is also provided, obtained from a Monte Carlo output. Input terms to the budget calculation are also provided.
For details on the motivation, methodology, data sources, results, and discussion pertaining to this dataset, see Morgan et al., 2026, Science.
Files and variables
File: global_terms.csv
In this file, each row represents a 10-year average. The net land and ocean sinks are given in PgC/yr. Each subsequent row advances the 10-year period by one year.
Variables
- start.yr: Start year of 10-year averaging window
- end.yr: End year of 10-year averaging window
- land2: Net land CO2 sink (PgC/yr), positive = uptake
- land2.pm: Net land CO2 sink 1-sigma uncertainty (PgC/yr)
- ocean2: Ocean CO2 sink (PgC/yr), positive = uptake
- ocean2.pm: Ocean CO2 sink 1-sigma uncertainty (PgC/yr)
- fossil: Fossil fuel CO2 emissions (PgC/yr), positive = source to atmosphere
- fossil.pm: Fossil fuel emissions 1-sigma uncertainty (PgC/yr)
- a.foss: Fossil fuel O2:CO2 oxidative ratio (mol/mol)
- a.foss.pm: Fossil fuel oxidative ratio 1-sigma uncertainty (mol/mol)
- a.lnd: Land O2:CO2 oxidative ratio (mol/mol)
- a.lnd.pm: Land oxidative ratio 1-sigma uncertainty (mol/mol)
- DCO2: Atmospheric CO2 increase (PgC/yr)
- DCO2.pm: Atmospheric CO2 increase 1-sigma uncertainty (PgC/yr)
- z.eff: Effective ocean O2 outgassing w/ N2 correction (Tmol/yr)
- z.eff.pm: Effective ocean O2 outgassing w/ N2 correction 1-sigma uncertainty (Tmol/yr)
- z.met: Metal production/consumption O2 apparent source (Tmol/yr)
- z.met.pm: Metal production/consumption O2 apparent source 1-sigma uncertainty (Tmol/yr)
- zo2: Total ocean O2 outgassing Z_eff - ZN2 (Tmol/yr)
- zo2.pm: Total ocean O2 outgassing 1-sigma uncertainty (Tmol/yr)
Code/software
This is a .csv file and is in ASCII text. It is readable through any text editor program. For further details, see the Github repository:
https://github.com/ejmorg/morgan_sinks_2026
This repository contains the code used to create this file.
Access information
Other publicly accessible locations of the data:
- Code used to generate this file: https://github.com/ejmorg/morgan_sinks_2026)
Data was derived from the following sources:
- Atmospheric δ(O₂/N₂) and CO₂: R. F. Keeling, E. J. Morgan, Atmospheric Flask O2/N2 and CO2 Data Sets – Multiple Sampling Stations. In Scripps O2 Program Data. UC San Diego Library Digital Collections. (2021). https://doi.org/10.6075/J0HT2PH4.
- Atmospheric CO₂ growth rate (DCO2): NOAA Global Monitoring Laboratory, globally averaged marine surface monthly means, X. Lan, P. Tans, K. W. Thoning, Trends in globally-averaged CO 2 determined from NOAA Global Monitoring Laboratory measurements (2025). https://doi.org/10.15138/9N0H-ZH07.
- Fossil fuel CO₂ emissions (fossil): Global Carbon Budget 2025 v0.7. See Friedlingstein, et al., 2025, Global Carbon Budget 2025. Earth System Science Data 18, 3211--3288. T
- Fossil fuel oxidative ratio (a.foss): R. F. Keeling, A. C. Manning, “Studies of Recent Changes in Atmospheric O2 Content” in Treatise on Geochemistry (Elsevier Ltd., ed. 2, 2014; http://dx.doi.org/10.1016/B978-0-08-095975-7.00420-4)vol. 5, pp. 385–404.
- Ocean heat content (used for z.eff): S. Levitus, J. I. Antonov, T. P. Boyer, O. K. Baranova, H. E. García, R. A. Locarnini, A. V. Mishonov, J. R. Reagan, D. Seidov, E. Yarosh, M. M. Zweng, NCEI ocean heat content and related anomalies from 1955 to present (NCEI Accession 0164586) (2017). https://doi.org/10.7289/V53F4MVP.
- Metal production (z.met): Apparent O2 source due to metal production from: M. O. Battle, A. Raynor, S. E. Kesler, R. F. Keeling, The Impact of Industrial Activity on the Amount of Atmospheric O2. Tellus B: Chemical and Physical Meteorology 75, 65–75 (2023).