Yearly Human-Induced Greenhouse Gas Emissions in CO2 Equivalent

What are the Yearly Human-Induced Greenhouse Gas Emissions in CO2 Equivalent?

These are the yearly greenhouse gas emissions that result from human activities. This includes the following emissions:

  • 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)

These emissions are the main drivers of human-induced warming. The total emissions reached 55±5.2 GtCO2e in 2021. The CO2-equivalent unit makes it possible to compare the relative emissions from different gasses. CO2-equivalents are calculated using the global warming potentials of the respective gasses, in this case using a 100-year time horizon.

Paper section 2 Emissions: Indicators of Global Climate Change 2022, Piers M. Forster et al.

In the scientific literature, human-induced emissions are often referred to as anthropogenic emissions.

CO2 fossil fuels and industry

In 2021, CO2 from fossil fuels and industry reached 37±3 GtCO2. The sources are mostly fossil-fuel combustion emissions from coal, oil, and gas, as well as emissions from industrial processes such as cement production.

CO2 land-use, land-use change and forestry

The CO2 emissions from land-use, land-use change and forestry were 3.9±2.8 GtCO2 in 2021. 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)

The 2021 methane emissions were 8.9±2.7 GtCO2e. They are emitted by human activities such as rearing livestock, agricultural practices, and fugitive fossil fuel emissions.

Nitrous oxide (N2O)

Nitrous oxide emissions reached 2.9±1.8 GtCO2e in 2021. Common sources of these emissions are fossil fuel emissions and the agricultural use of synthetic fertilizer and manure.

Fluorinated gasses (F-gasses)

The total emissions of fluorinated gasses amounted to 2.0 ±0.59 GtCO2e in 2021. Fluorinated gasses are a group of gasses defined by UNFCCC: hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6), and nitrogen trifluoride (NF3). Fluorinated gasses are also known as halogenated gasses.

Units and measures

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

Wikipedia: Gigatonne
Wikipedia: Global warming potential

Insights from this chart

Total emissions have risen almost continuously since the 1850s, and by staggering amounts in the last 100 years. Over the last 10 years, emissions have stabilized, but there is as yet no reduction in emissions, other than a temporary reduction in 2020 due to Covid.

CO2 emissions from fossil fuels and industry are by far the largest contributors to total emissions and have increased roughly ten-fold in the last 100 years. Emissions from methane, nitrous oxide and fluorinated gasses have all grown significantly over the same period. The CO2 emissions from land-use, land-use change and forestry have been relatively steady for a very long time and have had a large historic impact.

About the data

Climate Change Tracker is part of 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, and estimates of global temperature extremes.

Comparison with IPCC Assessment Report 6

The IPCC AR6 reported the average emissions per year for the 2010 to 2019 decade at 56±6 GtCO2e. A new reassessment of that same period, 2010 to 2019, resulted in slightly lower emissions of 53±5.6 GtCO2e, and the new assessment of the latest available period, 2012 till 2021, shows 54±5.3 GtCO2e.

IGCC Website: Indicators of Global Climate Change
Full Paper: Indicators of Global Climate Change 2022: Annual update of large-scale indicators of the state of the climate system and the human influence

The IGCC CO2 emissions data currently only contains Global Carbon Budget data since 1959. The historical data is taken directly from the Global Carbon Budget. The methane and nitrous oxide emissions data in IGCC is taken from PRIMAP.

Data sources

IGCC Indicators of Global Climate Change 2022
Credits: Chris Smith, Tristram Walsh, Alex Borger, Piers Forster, Nathan Gillett, Mathias Hauser, Willam Lamb, Robin Lamboll, Matthew Palmer, Aurélien Ribes, Dominik Schumacher, Sonia Seneviratne, Blair Trewin, & Karina von Schuckmann. (2023). Indicators of Global Climate Change 2022 (v2023.06.02). Zenodo. cycle: yearlyDelay: mixed

Global Carbon Budget 2022 Global Carbon Project
Credits: Friedlingstein et al. (2022) - full reference below **Update cycle: yearlyDelay: ~9 months after end of yearReference: ** Global Carbon Budget 2022, by Pierre Friedlingstein, Michael O'Sullivan, Matthew W. Jones, Robbie M. Andrew, Luke Gregor, Judith Hauck, Corinne Le Quéré, Ingrid T. Luijkx, Are Olsen, Glen P. Peters, Wouter Peters, Julia Pongratz, Clemens Schwingshackl, Stephen Sitch, Josep G. Canadell, Philippe Ciais, Robert B. Jackson, Simone R. Alin, Ramdane Alkama, Almut Arneth, Vivek K. Arora, Nicholas R. Bates, Meike Becker, Nicolas Bellouin, Henry C. Bittig, Laurent Bopp, Frédéric Chevallier, Louise P. Chini, Margot Cronin, Wiley Evans, Stefanie Falk, Richard A. Feely, Thomas Gasser, Marion Gehlen, Thanos Gkritzalis, Lucas Gloege, Giacomo Grassi, Nicolas Gruber, Özgür Gürses, Ian Harris, Matthew Hefner, Richard A. Houghton, George C. Hurtt, Yosuke Iida, Tatiana Ilyina, Atul K. Jain, Annika Jersild, Koji Kadono, Etsushi Kato, Daniel Kennedy, Kees Klein Goldewijk, Jürgen Knauer, Jan Ivar Korsbakken, Peter Landschützer, Nathalie Lefèvre, Keith Lindsay, Junjie Liu, Zhu Liu, Gregg Marland, Nicolas Mayot, Matthew J. McGrath, Nicolas Metzl, Natalie M. Monacci, David R. Munro, Shin-Ichiro Nakaoka, Yosuke Niwa, Kevin O'Brien, Tsuneo Ono, Paul I. Palmer, Naiqing Pan, Denis Pierrot, Katie Pocock, Benjamin Poulter, Laure Resplandy, Eddy Robertson, Christian Rödenbeck, Carmen Rodriguez, Thais M. Rosan, Jörg Schwinger, Roland Séférian, Jamie D. Shutler, Ingunn Skjelvan, Tobias Steinhoff, Qing Sun, Adrienne J. Sutton, Colm Sweeney, Shintaro Takao, Toste Tanhua, Pieter P. Tans, Xiangjun Tian, Hanqin Tian, Bronte Tilbrook, Hiroyuki Tsujino, Francesco Tubiello, Guido R. van der Werf, Anthony P. Walker, Rik Wanninkhof, Chris Whitehead, Anna Willstrand Wranne, Rebecca Wright,Wenping Yuan, Chao Yue, Xu Yue, Sönke Zaehle, Jiye Zeng, and Bo Zheng (2022), Earth System Science Data, 14, 4811–4900, 2022, DOI: 10.5194/essd-14-4811-2022.

PRIMAP The PRIMAP-hist national historical emissions time series (1750-2021)
Credits: Gütschow, J. and Pflüger, M.: The PRIMAP-hist national historical emissions time series (1750-2021) v2.4.2 (2.4.2),, 2023.Update cycle: yearly