Global Carbon Budget 2022
The annual releases of the Global Carbon Budget shed light on the recent evolution of anthropogenic CO₂ emissions, and on their partitioning between ocean, atmosphere and land. The ocean plays a crucial role in the global carbon cycle, and has taken up 2.9 billion tonnes of carbon (GtC) in the year 2021. This is equivalent to 26% of anthropogenic CO₂ emissions. Writing in Earth System Science Data, the authors use ten global ocean biogeochemistry models and seven surface ocean CO₂-based products to assess the ocean carbon sink 1958 to 2021. They highlight the growing discrepancy between model-based and observation-based estimates, which result in an uncertainty of a factor of three around the growth rate of the ocean carbon sink since 2010. With the aid of additional model simulations, the authors attribute the increase of the ocean carbon sink to rising atmospheric CO₂ levels. The effect of climate change is smaller, however, the ocean sink would have been 5% larger without climate change. All surface ocean CO₂ data and the full output of the models is available via https://globalcarbonbudgetdata.org/.
Reference: Friedlingstein, P., O'Sullivan, M., Jones, M.W., et al., (2022). Global Carbon Budget 2022. Earth Syst. Sci. Data, 14, 4811-4900. https://doi.org/10.5194/essd-14-4811-2022