Human-Induced Greenhouse Gas Emissions

Greenhouse gas emissions from human activities are the main drivers of human-induced warming. In the scientific literature, human-induced emissions are often referred to as anthropogenic emissions. They are grouped as follows:

• CO₂ Fossil Fuels and Industry (CO₂ FFI)
• CO₂ Land-Use, Land-Use Change and Forestry (CO₂ LULUCF)
• Methane (CH₄)
• Nitrous oxide (N₂O)
• Fluorinated gases (F-gases)

Emissions from all different gases are expressed in CO₂-equivalent units to make it possible to compare the relative emissions from these different gases. CO₂-equivalents are calculated using the global warming potentials of the respective gases, in this case using a 100-year time horizon.

CO₂ From Fossil Fuels and Industry

The sources are mostly fossil-fuel combustion emissions from coal, oil, and gas, as well as emissions from industrial processes such as cement production. Cement also absorbs CO₂ out of the atmosphere through carbonation, which reduces emissions by about 0.8 Gt per year and is included here.

CO₂ From Land-Use, Land-Use Change, and Forestry

The main driver of these emissions is deforestation, which includes logging and forest degradation, as well as other land-use change activities. The emissions also take into account the absorption of CO₂ by processes that remove CO₂ from the atmosphere, such as afforestation and reforestation. It is the net effect that is indicated here.

Methane (CH₄)

Methane emissions are caused by human activities such as rearing livestock, agricultural practices, and fugitive fossil fuel emissions.

Nitrous Oxide (N₂O)

Common sources of these emissions are fossil fuel emissions and the agricultural use of synthetic fertilizer and manure.

Fluorinated Gases (F-gases)

Fluorinated gases are a group of gases defined by UNFCCC: hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6), and nitrogen trifluoride (NF3). Fluorinated gases are also known as halogenated gases.

Key Take-Aways

• Greenhouse gas emissions 2023: Human activities have resulted in the equivalent of around 53 Gigatons CO₂-equivalent being released into the atmosphere on average each year over the last decade. In 2023, greenhouse gas emissions from human activities reached an all-time high of 54.6 gigatonnes (billion tonnes) of CO₂-equivalent.
• CO2 emissions 2024: Human activities resulted in 41.6 gigatonnes (billion tonnes) of CO₂ emissions—an all-time high in 2024. Data for other greenhouse gases in 2024 is expected later this year.
• This is primarily due to increasing greenhouse gas emissions from fossil fuels and industry. In 2024, there were also high emissions from tropical forest fires related to deforestation. Dry climatic conditions related to El Nino are favourable for wildfires.
• In 2024, emissions from international aviation (2.5% total emissions) – the sector with the steepest drop in emissions during the pandemic – reached pre-pandemic levels.
• Compared to a world in which there would be no climate action, we have made some progress. For example, without renewable energy deployment, emissions to meet the growing energy demand would have been even higher in 2024.
• However, compared to a world in which there was rapid, more ambitious climate action and deeper cuts to emissions, this assessment looks much less positive. Global emissions still have not peaked; in fact, they continue to rise. They could have been reducing by now.
• IPCC benchmark: In its most recent report, the Intergovernmental Panel on Climate Change (IPCC, the UN body responsible for assessing climate science) stated that global greenhouse gas emissions would need to peak before 2025 to limit warming to around 1.5°C. While the full assessment of greenhouse gas emissions in 2024 is not yet complete, the initial projection of CO₂ emissions from fossil fuels and land use change, from the Global Carbon Project, suggests that emissions have continued to rise. If this is the case, then we may have already passed one of the key IPCC benchmarks.
• Aerosols: As expected, the cooling aerosols continue to decline as a result of tackling air pollution, adding to the warming effect of greenhouse gases.

Units and Measures

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

About the Data

⚠️ Emissions marked as ‘Unknown’ are published on a different cycle throughout the year and will be updated later in 2025.

The data is produced by the Indicators of Global Climate Change (IGCC) initiative to spread indicators of climate change that are consistent with the IPCC Assessment Report 6. The IGCC produces estimates for key climate indicators: emissions of greenhouse gases and short-lived climate forcers, greenhouse gas concentrations, radiative forcing, surface temperature changes, the Earth’s energy imbalance, warming attributed to human activities, the remaining carbon budget, sea level rise, and estimates of global temperature extremes.

Data Sources

IGCC Indicators of Global Climate Change 2024: annual update of key indicators of the state of the climate system and human influence, Piers M. Forster et al.
Credits: Smith, C., Walsh, T., Gillett, N., Hauser, M., Krummel, P., Lamb, W., Lamboll, R., Mühle, J., Palmer, M., Ribes, A., Schumacher, D., Seneviratne, S., Trewin, B., von Schuckmann, K., & Forster, P. (2025). Indicators of Global Climate Change 2024 (v2025.05.02). Zenodo. Update cycle: yearlyDelay: mixed

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.

PRIMAP-hist The PRIMAP-hist national historical emissions time series (1750-2023)
Credits: Gütschow, Johannes ; Busch, Daniel ; Pflüger, Mika (2024): The PRIMAP-hist national historical emissions time series (1750-2023) v2.6. Zenodo.Update cycle: Every few monthsDelay: Less than 1 year