Nitrous oxide global budget

Table 8.4a Estimates of the global nitrous oxide budget (Tg N year from different sources and sinks...

Besides NOx oxides, there is nitrous oxide (N2O), which is of special interest in isotope geochemistry. N2O is present in air at around 300 ppb and increases by about 0.2% per year. Nitrous oxide is an important greenhouse gas that is, on a molecular basis, a much more effective contributor to global warming than CO2 and that is also a major chemical control on stratospheric ozone budgets. 

Finally, for the sake of completeness, the cycle of NzO is also plotted in Fig. 15. The values of the budget terms in this case are also very uncertain. However, the global N20 burden is rather well established by atmospheric measurements (see Subsection 3.5.2). We have to emphasize here that the quantity of NO molecules of surface origin reaching the stratosphere is relatively small as compared to the mass of nitrous oxide, owing to the relative atmospheric concentrations of these species. 

Nitrous oxide is another important greenhouse gas that is present in elevated concentrations in estuarine environments. At present, N2O is responsible for about 5-6% of the anthropogenic greenhouse effect and is increasing in the atmosphere at a rate of about 0.25% per year. However, the role of estuaries in the global budget of the gas has only been addressed recently. 

Elkins, J., 1990, Current Uncertainties in the Global Atmospheric N2O Budget, European Workshop on the Emission of Nitrous Oxide, Lisbon, Portugal, June 6-8, 1990. (Prom Hofmann, J. E., Johnson, R. A., Schumacher, P. D., Sload, A., Afonso, R., 1993, Post Combustion NO, Control for Coal-Fired Utility Boilers, paper presented at the 1993 Joint Symposium on Stationary Combustion NO, Control—EPRI/EPA, Bal Harbour, FL, May 24-27.)... 

Levine, J. S., 1991, The Global Atmospheric Budget of Nitrous Oxide, paper presented at the EPA/EPRI 1991 Joint Symposium on Stationary Combustion NO, Control— EPA/EPRI, Washington, D.C., March 25-28. 

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