Yearly Absorption of Human-Induced Gross CO2 Emissions

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.

Wikipedia: Carbon Cycle
Wikipedia: Carbon Sink

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.

Wikipedia: Carbon Dioxide in Earth's Atmosphere

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.

Wikipedia: Ocean Acidification

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.

Wikipedia: Land use, land-use change, and forestry

Units and measures

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

Wikipedia: Gigatonne

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 nagative.

IPCC: Annual Report 6, Chapter 5.2.1.4: Land CO2 Fluxes: Historical and Contemporary Variability and Trends
Wikipedia: Fertilization Effect

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.

United Nations: Net Zero Coalition

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 2023 are projections by the Global Carbon Project. The 2023 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 2023 is projected to equal that of 2022. The 2023 projection for the atmosphere is updated based on the monthly values from NOAA, which are in the Yearly CO2 Atmospheric Increase chart.

Yearly Atmospheric CO2 Increase

Data sources

Global Carbon Budget 2023 Global Carbon Budget
Credits: Friedlingstein et al., 2023b, ESSD, full reference below**Update 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., Bakker, D. C. E., Hauck, J., Landschützer, P., Le Quéré, C., Luijkx, I. T., Peters, G. P., Peters, W., Pongratz, J., Schwingshackl, C., Sitch, S., Canadell, J. G., Ciais, P., Jackson, R. B., Alin, S. R., Anthoni, P., Barbero, L., Bates, N. R., Becker, M., Bellouin, N., Decharme, B., Bopp, L., Brasika, I. B. M., Cadule, P., Chamberlain, M. A., Chandra, N., Chau, T.-T.-T., Chevallier, F., Chini, L. P., Cronin, M., Dou, X., Enyo, K., Evans, W., Falk, S., Feely, R. A., Feng, L., Ford, D. J., Gasser, T., Ghattas, J., Gkritzalis, T., Grassi, G., Gregor, L., Gruber, N., Gürses, Ö., Harris, I., Hefner, M., Heinke, J., Houghton, R. A., Hurtt, G. C., Iida, Y., Ilyina, T., Jacobson, A. R., Jain, A., Jarníková, T., Jersild, A., Jiang, F., Jin, Z., Joos, F., Kato, E., Keeling, R. F., Kennedy, D., Klein Goldewijk, K., Knauer, J., Korsbakken, J. I., Körtzinger, A., Lan, X., Lefèvre, N., Li, H., Liu, J., Liu, Z., Ma, L., Marland, G., Mayot, N., McGuire, P. C., McKinley, G. A., Meyer, G., Morgan, E. J., Munro, D. R., Nakaoka, S.-I., Niwa, Y., O'Brien, K. M., Olsen, A., Omar, A. M., Ono, T., Paulsen, M., Pierrot, D., Pocock, K., Poulter, B., Powis, C. M., Rehder, G., Resplandy, L., Robertson, E., Rödenbeck, C., Rosan, T. M., Schwinger, J., Séférian, R., Smallman, T. L., Smith, S. M., Sospedra-Alfonso, R., Sun, Q., Sutton, A. J., Sweeney, C., Takao, S., Tans, P. P., Tian, H., Tilbrook, B., Tsujino, H., Tubiello, F., van der Werf, G. R., van Ooijen, E., Wanninkhof, R., Watanabe, M., Wimart-Rousseau, C., Yang, D., Yang, X., Yuan, W., Yue, X., Zaehle, S., Zeng, J., and Zheng, B.: Global Carbon Budget 2023, Earth Syst. Sci. Data, 15, 5301–5369, https://doi.org/10.5194/essd-15-5301-2023, 2023.

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