EGU23-6
https://doi.org/10.5194/egusphere-egu23-6
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Nitrous Oxide and Climate

William van Wijngaarden, Cornelis de Lange, James Ferguson, and Will Happer
William van Wijngaarden et al.
  • York University, Physics, Toronto, Canada (wavw@yorku.ca)

Higher concentrations of atmospheric nitrous oxide are expected to slightly warm Earth's surface because of an increase in radiative forcing.  For current concentrations of greenhouse gases, the radiative forcing per added N2O molecule, is about 230 times larger than the forcing per added carbon dioxide molecule.  This is due to the heavy saturation of the absorption band of the relatively abundant greenhouse gas, CO2, compared to the much smaller saturation of the absorption bands of the trace greenhosue gas N2O.  But the rate of increase of CO2 molecules, about 2.5 ppm/year is about 3000 times larger than the rate of increase of N2O molecules, which has held steady at around 0.85 ppb/year since 1985.  So the contribution of nitrous oxide to the annual increase in forcing is 230/3000 or about 1/13 that of CO2.  If the main greenhouse gases, CO2, CH4 and N2O have contributed about 0.1 K/decade of the warming observed over the past few decades, this would correspond to about 0.00064 K per year or 0.064 K per century of warming from N2O.  This rather small warming does not support placing harsh restrictions on nitrous oxide emissions, which could seriously jeopardize world food supplies.

How to cite: van Wijngaarden, W., de Lange, C., Ferguson, J., and Happer, W.: Nitrous Oxide and Climate, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-6, https://doi.org/10.5194/egusphere-egu23-6, 2023.