Global Carbon Budget 2024

Earth system science data, Journal Year: 2025, Volume and Issue: 17(3), P. 965 - 1039

Published: March 14, 2025

Abstract. Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, terrestrial biosphere in a changing climate is critical to better understand global cycle, support development policies, project future change. Here we describe synthesize datasets methodologies quantify five major components budget uncertainties. Fossil CO2 (EFOS) are based on energy statistics cement production data, while from land-use change (ELUC) data bookkeeping models. Atmospheric concentration measured directly, its growth rate (GATM) computed annual changes concentration. The net uptake by ocean (SOCEAN, called sink) estimated with biogeochemistry models observation-based fCO2 products (fCO2 fugacity CO2). land (SLAND, dynamic vegetation Additional lines evidence sinks provided atmospheric inversions, oxygen measurements, Earth system sum all sources results imbalance (BIM), measure imperfect incomplete understanding contemporary cycle. All uncertainties reported as ±1σ. For year 2023, EFOS increased 1.3 % relative 2022, fossil at 10.1 ± 0.5 GtC yr−1 (10.3 when carbonation sink not included), ELUC was 1.0 0.7 yr−1, for total emission (including 11.1 0.9 (40.6 3.2 GtCO2 yr−1). Also, GATM 5.9 0.2 (2.79 0.1 ppm yr−1; denotes parts per million), SOCEAN 2.9 0.4 SLAND 2.3 near-zero BIM (−0.02 averaged over 2023 reached 419.31 ppm. Preliminary 2024 suggest an increase +0.8 (−0.2 1.7 %) globally 2.87 ppm, reaching 422.45 52 above pre-industrial level (around 278 1750). Overall, mean trend consistently period 1959–2023, overall imbalance, although discrepancies up around 1 persist representation semi-decadal variability fluxes. Comparison estimates multiple approaches observations shows following: (1) persistent large uncertainty estimate emissions, (2) low agreement between different methods magnitude flux northern extra-tropics, (3) discrepancy sink. This living-data update documents applied this most recent well evolving community presented work available https://doi.org/10.18160/GCP-2024 (Friedlingstein et al., 2024).

Language: Английский

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Comment on essd-2024-519

Published: Jan. 6, 2025

Abstract. Accurate assessment of anthropogenic carbon dioxide (CO₂) emissions and their redistribution among the atmosphere, ocean, terrestrial biosphere in a changing climate is critical to better understand global cycle, support development policies, project future change. Here we describe synthesise datasets methodologies quantify five major components budget uncertainties. Fossil CO₂ (E_FOS) are based on energy statistics cement production data, while from land-use change (E_LUC) data bookkeeping models. Atmospheric concentration measured directly, its growth rate (G_ATM) computed annual changes concentration. The ocean sink (S_OCEAN) estimated with biogeochemistry models observation-based fCO₂-products. (S_LAND) dynamic vegetation Additional lines evidence land sinks provided by atmospheric inversions, oxygen measurements Earth System Models. sum all sources results imbalance (B_IM), measure imperfect incomplete understanding contemporary cycle. All uncertainties reported as ±1σ. For year 2023, E_FOS increased 1.3 % relative 2022, fossil at 10.1 ± 0.5 GtC yr^-1 (10.3 when carbonation not included), E_LUC was 1.0 0.7 yr^-1, for total emission (including sink) 11.1 0.9 (40.6 3.2 GtCO₂ yr^-1). Also, G_ATM 5.9 0.2 (2.79 0.1 ppm yr^-1), S_OCEAN 2.9 0.4 S_LAND 2.3 near zero B_IM (-0.02 averaged over 2023 reached 419.3 ppm. Preliminary 2024, suggest an increase +0.8 (-0.3 1.9 %) globally, 2.8 reaching 422.5 ppm, 52 above pre-industrial level (around 278 1750). Overall, mean trend consistently period 1959–2023, near-zero overall imbalance, although discrepancies up around 1 persist representation semi-decadal variability fluxes. Comparison estimates multiple approaches observations shows: (1) persistent large uncertainty estimate emissions, (2) low agreement between different methods magnitude flux northern extra-tropics, (3) discrepancy sink. This living update documents applied this most-recent well evolving community presented work available https://doi.org/10.18160/GCP-2024 (Friedlingstein et al., 2024).

Language: Английский

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Trends in Sea‐Air CO₂ Fluxes and Sensitivities to Atmospheric Forcing Using an Extremely Randomized Trees Machine Learning Approach

Global Biogeochemical Cycles, Journal Year: 2025, Volume and Issue: 39(2)

Published: Feb. 1, 2025

Abstract Monthly global sea‐air CO 2 flux maps are created on a 1° by grid from surface water fugacity of (fCO 2w ) observations using an extremely randomized trees (ET) machine learning technique (AOML‐ET) over the period 1998–2020. Global patterns and magnitudes fCO AOML‐ET consistent with other methods updated climatology Takahashi et al. (2009, https://doi.org/10.1016/j.dsr2.2008.12.009 ). However, magnitude trends fluxes sensitive to treatment atmospheric forcing. In default configuration AOML‐ET, average is −1.70 PgC yr −1 negative trend −0.89 ± 0.19 decade . The large driven small uptake at beginning record. This leads increasing gradients time, particularly high latitudes. changing target variable in difference, ∆fCO , results lower −0.51 though remains similar −1.65 close consensus ocean models Carbon Budget −0.46 0.11 switching gas transfer parameterization weaker wind speed dependence reduces 60% but does not affect trend. Substituting spatially resolved marine air mole fraction product for zonally invariant boundary layer yields greater influx up 20% industrialized continental outflow regions.

Language: Английский

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An updated synthesis of ocean total alkalinity and dissolved inorganic carbon measurements from 1993 to 2023: the SNAPO-CO₂-v2 dataset

Earth system science data, Journal Year: 2025, Volume and Issue: 17(3), P. 1075 - 1100

Published: March 14, 2025

Abstract. Total alkalinity (AT) and dissolved inorganic carbon (CT) in the oceans are important properties to understand ocean cycle its link with global change (ocean sinks sources, acidification) ultimately find carbon-based solutions or mitigation procedures (marine removal). We present an extended database (SNAPO-CO2; Metzl et al., 2024c) 24 700 new additional data for period 2002 2023. The full now includes more than 67 000 AT CT observations along basic ancillary (time space location, depth, temperature, salinity) various oceanic regions obtained since 1993 mainly framework of French research projects. This both surface water columns acquired open oceans, coastal zones, rivers, Mediterranean Sea, either from time series stations punctual cruises. Most this synthesis were measured discrete samples using same closed-cell potentiometric titration calibrated certified reference material, overall accuracy ±4 µmol kg−1 CT. technique was used on board underway measurements during cruises conducted southern Indian Southern oceans. these also added synthesis. provided one dataset (https://doi.org/10.17882/102337, that offers a direct use regional purposes, e.g., AT–salinity relationships, long-term estimates, constraint validation diagnostics reconstructed fields, coupled climate–carbon models simulations, derived Biogeochemical Argo (BGC-Argo) floats. These can be calculate pH, fugacity CO2 (fCO2), other system derive acidification rates air–sea fluxes.

Language: Английский

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An improved long-term high-resolution surface pCO2 data product for the Indian Ocean using machine learning

Scientific Data, Journal Year: 2025, Volume and Issue: 12(1)

Published: April 5, 2025

Accurate estimation of surface ocean pCO2 is crucial for understanding the ocean's role in global carbon cycle and its response to climate change. In this study, we employ a machine learning algorithm correct deviations high-resolution (1/12°) model simulations from INCOIS-BIO-ROMS (pCO2model) period 1980-2019, using available observations (pCO2obs). We train XGBoost generate spatio-temporal (pCO2obs - pCO2model) pCO2model. The interannually climatologically varying are then added back original separately, which results an improved data product. A comparison our product with moored observations, gridded SOCAT, CMEMS-LSCE-FFNN, OceanSODA demonstrates improvement by approximately 40% ± 3.31% RMSE. Further analysis reveals that adding climatological pCO2model greater improvements than interannual deviations. This underscores ability algorithms enhance accuracy model-simulated outputs.

Language: Английский

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Seasonality of pCO2 and air-sea CO2 fluxes in the Central Labrador Sea

Frontiers in Marine Science, Journal Year: 2024, Volume and Issue: 11

Published: Oct. 25, 2024

The Labrador Sea in the subpolar North Atlantic is known for its large air-to-sea CO 2 fluxes, which can be around 40% higher than other regions of intense ocean uptake like Eastern Pacific and within Northwest Atlantic. This region also a hot-spot storage anthropogenic . Deep water formed here, so that dissolved gas by surface directly connects to deeper waters, helping determine how much atmospheric may sequestered (or released) deep ocean. Currently, Central acts as year-round sink , with intensification driven biological production spring lasting through summer fall. Observational estimates air-sea fluxes rely upon very limited, scattered data distinct lack wintertime observations. Here, we compile observations p from moorings underway measurements, including previously unreported data, between 2000 2020, create baseline seasonal climatology Sea. used reference compare against observational-based statistical regional collection global products. comparison reveals systematic differences representation cycle uncertainties magnitude fluxes. analysis paramount importance long-term, seasonally-resolved coverage this order accurately quantify size present sensitivity climate perturbations.

Language: Английский

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