These are the total yearly nitrous oxide (N2O) emitted through human activities expressed as weight in teragrams. In the scientific literature, this is referred to as anthropogenic N2O emissions. Examples of human emissions include the agricultural use of synthetic fertilizer and manure and fossil fuel emissions as well as other sources, which you find in the next breakdown chart.
Human-induced emissions are the main driver of the increasing atmospheric nitrous oxide that is warming our planet.
Wikipedia: Nitrous_oxide Emissions_by_sourceThe unit teragram describes the average weight of atmospheric nitrous oxide per year.
Wikipedia: TeragramSince 1980, yearly human nitrous oxide emissions have increased significantly from about 5 to 8 teragrams per year. IPCC scientific sources do not have information on human emissions before 1980.
There are also natural processes that together emit roughly 10 teragrams of nitrous oxide per year. There is only one significant process that eliminates nitrous oxide, removing roughly 13.5 teragrams from the atmosphere per year: a chemical breakdown process happening in the stratosphere (the second layer of the atmosphere). Overall, natural processes remove approximately 3.5 teragrams per year. This means that human emissions above 3.5 teragrams result in an atmospheric increase, which you can see in the Yearly Atmospheric N2O Increase chart.
There is a very long delay in the data. This is because this data is produced periodically by a global research project where scientists contribute to a mutually agreed knowledge base. It takes a lot of time and effort to generate trustworthy data that we can be confident in.
Further readings:
Yearly Atmospheric N2O Increase chartThe Global Carbon Project has a Global Nitrous Oxide Budget besides its Global Carbon Budget. It uses inventories, models, atmospheric inversions and more to build up the inventory.
Global Nitrous Oxide Budget 2020 Global Carbon Project
Credits: A comprehensive quantification of global nitrous oxide sources and sinks by Hanqin Tian, Rongting Xu, Josep G. Canadell, Rona L. Thompson, Wilfried Winiwarter, Parvadha Suntharalingam, Eric A. Davidson, Philippe Ciais, Robert B. Jackson, Greet Janssens-Maenhout, Michael J. Prather, Pierre Regnier, Naiqing Pan, Shufen Pan, Glen Peters, Hao Shi, Francesco N. Tubiello, Sönke Zaehle, Feng Zhou, Almut Arneth, Gianna Battaglia, Sarah Berthet, Laurent Bopp, Alexander F. Bouwman, Erik T. Buitenhuis, Jinfeng Chang, Martyn P. Chipperfield, Shree R.S. Dangal, Edward Dlugokencky, James Elkins, Bradley D. Eyre, Bojie Fu, Bradley Hall, Akihiko Ito, Fortunat Joos, Paul B. Krummel, Angela Landolfi, Goulven G. Laruelle, Ronny Lauerwald, Wei Li, Sebastian Lienert, Taylor Maavara, Michael MacLeod, Dylan B. Millet, Stefan Olin, Prabir K. Patra, Ronald G. Prinn, Peter A. Raymond, Daniel J. Ruiz, Guido R. van der Werf, Nicolas Vuichard, Junjie Wang, Ray Weiss, Kelley C. Wells, Chris Wilson, Jia Yang, and Yuanzhi Yao (2020), Nature, DOI:10.1038/s41586-020-2780-0Delay: ~ 6 years