Breakdown of Yearly Human-Induced CO2 Absorption

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

This is a breakdown by human activities and processes of the yearly CO2 absorption expressed in gigatonnes. It is critical to know and track the sources of human CO2 absorption in order to understand how they can reduce human net emissions.

The human activities and processes that absorb CO2 are

  • Land-Use Change
  • Cement Carbonation

Land-use Change

Absorption from land-use change is from the changes we make to the land and how we manage land. Absorption comes, for example, from afforestation and other regrowth. Land-use change also emits considerable amounts of CO2, as shown in the emissions breakdown chart. Land-use change emits more than it absorbs, so the net effect is still emissions, although less than from coal, oil and gas.

Cement Carbonation

When cement is created, it starts to absorb CO2 from the atmosphere, and this process is called cement carbonation. However, the process of creating cement also emits CO2, about twice as much as the created cement will absorb. These emissions are included in the Other Fossil group of the Breakdown of Human-Induced CO2 Emissions chart.

Technologies like carbon capture at fossil power stations reduce the emissions before they are emitted and therefore are not part of these absorptions.

Wikipedia: Greenhouse Gas Emissions
Earth System Science Data: GCP 2020 paper: Section 2.2 Land-use change; Section 2.1 Fossil fuel emissions
IPCC: Annual Report 6, Anthropogenic CO2 emissions

Units and measures

CO2 absorption is expressed in the total weight in gigatonnes.

Wikipedia: Gigatonne

Insights from this chart

Land-use change absorption is by far the largest absorber and is in a growing trend. The land-use change emissions are larger but relatively steady. This means that the net effect of land-use change is currently at roughly 3 gigatonnes and in a reducing trend.

Cement carbonation is growing. The absorption of CO2 by cement encompasses roughly half of the emissions that were released when the cement was created. This means that, at the moment, creating more cement structures is not a solution to the rising CO2 levels.

Global Carbon Project: Global Carbon Budget Presentation

About the data

The Global Carbon Project has human absorption data on land-use change and cement carbonation. Cement carbonation is an average of two estimates. Land-use change absorption values come from three bookkeeping models. There are large uncertainties in the land-use values before 1960. The values for 2023 are projections by the Global Carbon Project. The Global Carbon Project did not project changes in reforestation and the human-induced absorption in 2023 is projected to equal that of 2022.

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,, 2023.