What is the Yearly Absorption of Human-Induced CO₂ Emissions?

This is the yearly total amount of anthropogenic CO₂ emissions absorbed by the atmosphere, land, oceans and human activities expressed in gigatonnes. All human-made CO₂ emissions initially go into the atmosphere. CO₂ is then absorbed from the atmosphere partially and indirectly by land, ocean and human activities. This chart shows the yearly distribution of where the anthropogenically emitted CO₂ ends up. Before human civilization started emitting a lot of CO₂ there was a natural balance between carbon dioxide in the atmosphere and carbon on land and in the ocean.

It is critical to understand where the human-made emissions are absorbed because of the different consequences.

Atmosphere

The absorption of CO₂ by the atmosphere is the amount by which atmospheric CO₂ increases, and it is in fact the same thing as the Yearly Atmospheric CO₂ Increase you can see in the first chart. It is the main driver of global warming.

Land

Absorption of CO₂ on land mainly happens through vegetation growth. We only consider natural processes in this group. This is also known as the land sink.

Ocean

The oceans dissolve atmospheric CO₂ in a process that is also known as the ocean sink. Ocean absorption results in ocean acidification and impacts life in the seas and oceans.

Human-Induced

Certain human activities absorb CO₂. Absorption by human activities largely goes into human-managed plant growth and cement carbonation. The absorptions are responsible for the difference between net and gross human emissions.

Units and measures

CO₂ absorption is expressed in the total weight in gigatonnes per year.

Insights from this chart

The absorption by land is growing because of increased plant growth in the northern hemisphere due to rising atmospheric CO₂ levels and lengthened growing seasons. This chart has high fluctuations because plant growth depends on many irregular factors.

In the last 150 years, there were some years, like 1861 and 1862, where the land emitted more CO₂ into the atmosphere than it absorbed. Hence, those values are negative.

The absorption of atmospheric CO₂ by the ocean is steadily increasing as this is dependent on the level of CO₂ in the atmosphere. Unfortunately, this causes ocean acidification and introduces many underlying problems.

The steadily increasing human absorption is small compared to human emissions. At the moment, human absorption comes from two underlying processes, namely land-use change and cement carbonation, and both have related emissions that are higher than their respective absorption. Absorption technologies may become important technologies to make human absorption equal human emissions and ensure a net-zero human impact. Technologies like carbon capture at fossil power stations reduce the emissions before they are emitted and are therefore not part of these absorptions.

About the data

The Global Carbon Project shares data on atmospheric CO₂, the ocean sink, the land sink and human absorption by land-use change and cement carbonation. The atmospheric CO₂ data is taken directly from the source, NOAA, to include latest updates and is taken from CO₂ measurement stations across the world. The ocean and land sink values are based on combinations of many ocean and vegetation models. Land-use change absorption values come from three bookkeeping models that also estimate land-use change emissions. There are large uncertainties in the land-use values before 1960.

The values for 2024 are projections by the Global Carbon Project. The 2024 land-use projection is only given for changes in net land-use emissions. The Global Carbon Project did not project changes in reforestation and the human-induced absorption in 2024 is projected to equal that of 2023. The 2024 projection for the atmosphere is updated based on the monthly values from NOAA, which are also seen in the Yearly CO₂ Atmospheric Increase chart.

Data sources

Global Carbon Budget 2024 Global Carbon Budget
Credits: Friedlingstein et al., 2024, ESSDUpdate cycle: yearlyDelay: ~ 10 months after end of a year. Current year values estimates published in November.Reference: Friedlingstein, P., O'Sullivan, M., Jones, M. W., Andrew, R. M., Hauck, J., Landschützer, P., Le Quéré, C., Li, H., Luijkx, I. T., Olsen, A., Peters, G. P., Peters, W., Pongratz, J., Schwingshackl, C., Sitch, S., Canadell, J. G., Ciais, P., Jackson, R. B., Alin, S. R., Arneth, A., Arora, V., Bates, N. R., Becker, M., Bellouin, N., Berghoff, C. F., Bittig, H. C., Bopp, L., Cadule, P., Campbell, K., Chamberlain, M. A., Chandra, N., Chevallier, F., Chini, L. P., Colligan, T., Decayeux, J., Djeutchouang, L., Dou, X., Duran Rojas, C., Enyo, K., Evans, W., Fay, A., Feely, R. A., Ford, D. J., Foster, A., Gasser, T., Gehlen, M., Gkritzalis, T., Grassi, G., Gregor, L., Gruber, N., Gürses, Ö., Harris, I., Hefner, M., Heinke, J., Hurtt, G. C., Iida, Y., Ilyina, T., Jacobson, A. R., Jain, A., Jarníková, T., Jersild, A., Jiang, F., Jin, Z., Kato, E., Keeling, R. F., Klein Goldewijk, K., Knauer, J., Korsbakken, J. I., Lauvset, S. K., Lefèvre, N., Liu, Z., Liu, J., Ma, L., Maksyutov, S., Marland, G., Mayot, N., McGuire, P., Metzl, N., Monacci, N. M., Morgan, E. J., Nakaoka, S.-I., Neill, C., Niwa, Y., Nützel, T., Olivier, L., Ono, T., Palmer, P. I., Pierrot, D., Qin, Z., Resplandy, L., Roobaert, A., Rosan, T. M., Rödenbeck, C., Schwinger, J., Smallman, T. L., Smith, S., Sospedra-Alfonso, R., Steinhoff, T., Sun, Q., Sutton, A. J., Séférian, R., Takao, S., Tatebe, H., Tian, H., Tilbrook, B., Torres, O., Tourigny, E., Tsujino, H., Tubiello, F., van der Werf, G., Wanninkhof, R., Wang, X., Yang, D., Yang, X., Yu, Z., Yuan, W., Yue, X., Zaehle, S., Zeng, N., and Zeng, J.: Global Carbon Budget 2024, Earth Syst. Sci. Data Discuss. [preprint], https://doi.org/10.5194/essd-2024-519, in review, 2024.

Globally averaged marine surface annual mean rates data NOAA's Global Monitoring Laboratory
Credits: Ed Dlugokencky and Pieter Tans, NOAA/GML (gml.noaa.gov/ccgg/trends/)Update cycle: yearlyDelay: ~ 3 months

Globally averaged marine surface annual mean growth rates data NOAA's Global Monitoring Laboratory
Credits: Ed Dlugokencky and Pieter Tans, NOAA/GML (gml.noaa.gov/ccgg/trends/)Update cycle: monthlyDelay: ~ 3 months

Globally averaged marine surface monthly mean data NOAA's Global Monitoring Laboratory
Credits: Ed Dlugokencky and Pieter Tans, NOAA/GML (gml.noaa.gov/ccgg/trends/)Update cycle: monthlyDelay: ~ 3 months

Estimated Global Trend daily values NOAA's Global Monitoring Laboratory
Credits: Ed Dlugokencky and Pieter Tans, NOAA/GML (gml.noaa.gov/ccgg/trends/)Update cycle: dailyDelay: ~ 2 days