Human-Induced Yearly CO2 Emissions

What are the Human-Induced Yearly CO2 Emissions?

This refers to the total yearly CO2 emitted through human activities, such as the combustion of fossil fuels, expressed in gigatonnes. In the scientific literature, it is referred to as anthropogenic emissions. Anthropogenic CO2 emissions are critical because they are the main driver of the increasing atmospheric CO2 that is warming the Earth. Human-induced CO2 emissions also cause an increase in CO2 absorption by the ocean, which leads to ocean acidification.

There is an important distinction between net and gross emissions that we must bear in mind. Gross emissions are the total sum of emissions from human activity that emit CO2 into the atmosphere. Net emissions take the absorption by human activities into account to highlight the net effect of human activities.

Wikipedia: Greenhouse Gas Emissions
Global Carbon Project: Global Carbon Budget Presentation

Units and measures

CO2 emissions are expressed in the total weight in gigatonnes per year.

Wikipedia: Gigatonne

Insights from this chart

Up until the 1940s, a long period of a slow and steady rise in CO2 emissions was driven by coal combustion and land-use changes, such as deforestation. There was a temporary decrease of emissions during the two world wars and the Great Depression. After the Second World War there was a strong rise in oil use, which led to a 20-year period of increasing emissions. Through the 70s, 80s and 90s, emissions still increased every year, but more slowly, with some years of decrease around the two oil crises and the dissolution of the Soviet Union.

The significant peak in 1997 is from Indonesian forest fires due to changes in land use.

In the early 2000s, rapid development in China caused a major increase in emissions from coal combustion. The USA and Europe, which have historically emitted the most CO2 emissions, have seen a decrease in emissions since roughly 2008, mostly from reduced coal combustion.

About the data

The Global Carbon Project data for human emissions is the sum of fossil CO2 emissions plus land-use change emissions. The fossil data is based on four main datasets containing global and national CO2 emissions. The uncertainty in global fossil CO2 emissions is estimated at ±5%. The land use change emissions are based on three bookkeeping models; these models also estimate the land-use change absorption. 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 CO2 Atmospheric 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,, 2023.