These are the total yearly methane (CH4) emissions from human activities expressed as weight in megatonnes (Mt). In the scientific literature, these are referred to as anthropogenic emissions. Examples of human-induced emissions include rearing livestock, fugitive and combustion emissions from fossil fuels, and other sources, as you can see in the next breakdown chart.Breakdown of Human-Induced Yearly Methane Emissions
Human-induced methane emissions increase atmospheric methane, which is warming the Earth. It has a large warming effect, especially since it has a much higher Global Warming Potential (GWP) than CO2. However, the effect lasts only for a relatively brief period (9 years on average), compared to hundreds of years for CO2. A reduction in emissions can cause a rapid decline in its atmospheric levels and climate impact.Wikipedia: Methane Emissions
The unit megatonne (Mt) describes the weight of emitted methane per year.Wikipedia: Megatonne
There has been steady growth in human-induced methane emissions since 1850. There was a period of fast growth between 1950 and 1970, which was largely due to the growth of the oil industry and the increased rearing of livestock; The oil industry releases large amounts of fugitive methane.
Current human-induced methane emissions are around 300 Mt per year, and all of these emissions end up in the atmosphere. The yearly increase in atmospheric methane is almost 50 Mt per year. The difference (around 250 Mt) is due to natural sinks of methane that remove methane from the atmosphere, such as atmospheric breakdown.
The scientific community has a high confidence in the accuracy of the atmospheric increase values, and is reasonably confident about the human emissions; however, there is less confidence about the natural emissions and natural sinks of methane.Wikipedia: Megatonne
The PRIMAP-hist dataset is a rich dataset that combines several published sources to create a historic emissions time series for methane and many other greenhouse gasses.PRIMAP-hist
PRIMAP-histCredits: Gütschow, J. and Pflüger, M.: The PRIMAP-hist national historical emissions time series (1750-2021) v2.4.2 (2.4.2), https://doi.org/10.5281/zenodo.7727475, 2023.Update cycle: yearlyDelay: 1-2 years