Estimates of the Climate Response to Aircraft CO2 and NOx Emissions Scenarios

A combination of linear response models is used to estimate the transient changes in the global means of carbon dioxide (CO2) concentration, surface temperature, and sea level due to aviation. Apart from CO2, the forcing caused by ozone (O3) changes due to nitrogen oxide (NOx) emissions from aircraft is also considered. The model is applied to aviation using several CO2 emissions scenarios, based on reported fuel consumption in the past and scenarios for the future, and corresponding NOx emissions. Aviation CO2 emissions from the past until 1995 enlarged the atmospheric CO2 concentration by 1.4 ppmv (1.7% of the anthropogenic CO2 increase since 1800). By 1995, the global mean surface temperature had increased by about 0.004 K, and the sea level had risen by 0.045 cm. In one scenario (Fa1), which assumes a threefold increase in aviation fuel consumption until 2050 and an annual increase rate of 1% thereafter until 2100, the model predicts a CO2 concentration change of 13 ppmv by 2100, causing temperature increases of 0.01, 0.025, 0.05 K and sea level increases of 0.1, 0.3, and 0.5 cm in the years 2015, 2050, and 2100, respectively. For other recently published scenarios, the results range from 5 to 17 ppmv for CO2 concentration increase in the year 2050, and 0.02 to 0.05 K for temperature increase. Under the assumption that present-day aircraft-induced O3 changes cause an equilibrium surface warming of 0.05 K, the transient responses amount to 0.03 K in surface temperature for scenario Fa1 in 1995. The radiative forcing due to an aircraft-induced O3 increase causes a larger temperature change than aircraft CO2 forcing. Also, climate reacts more promptly to changes in O3 than to changes in CO2 emissions from aviation. Finally, even under the assumption of a rather small equilibrium temperature change from aircraft-induced O3 (0.01 K for the 1992 NOx emissions), a proposed new combustor technology which reduces specific NOx emissions will cause a smaller temperature change during the next century than the standard technology does, despite a slightly enhanced fuel consumption. Regional effects are not considered here, but may be larger than the global mean responses.

[1]  Anu Vedantham,et al.  Long-term scenarios for aviation: Demand and emissions of CO2 and NOx , 1998 .

[2]  Corinne Le Quéré,et al.  An efficient and accurate representation of complex oceanic and biospheric models of anthropogenic carbon uptake , 1996 .

[3]  Robert Sausen,et al.  Time-dependent greenhouse warming computations with a coupled ocean-atmosphere model , 1992 .

[4]  K. Hasselmann,et al.  Transport and storage of CO2 in the ocean ——an inorganic ocean-circulation carbon cycle model , 1987 .

[5]  Ian G. Enting,et al.  Future emissions and concentrations of carbon dioxide: Key ocean / atmosphere / land analyses , 1994 .

[6]  Climatic impact of aircraft induced ozone changes , 1997 .

[7]  F. Deidewig,et al.  The ANCAT/EC global inventory of NOx emissions from aircraft , 1997 .

[8]  J. Houghton.  Climate change 1994 : radiative forcing of climate change and an evaluation of the IPCC IS92 emission scenarios , 1995 .

[9]  J. Hansen,et al.  Radiative forcing and climate response , 1997 .

[10]  E. Maier‐Reimer.  The biological pump in the greenhouse , 1993 .

[11]  H.-G. Nüßer,et al.  The Global Distribution of Air Traffic at High Altitudes, Related Fuel Consumption and Trends , 1990 .

[12]  Fortunat Joos,et al.  Use of a simple model for studying oceanic tracer distributions and the global carbon cycle , 1992 .

[13]  Steven L. Baughcum,et al.  Scheduled Civil Aircraft Emission Inventories for 1976 and 1984: Database Development and Analysis , 1996 .

[14]  Ulrich Schumann,et al.  The impact of nitrogen oxides emissions from aircraft upon the atmosphere at flight altitudes—results from the aeronox project , 1997 .

[15]  R. Sausen,et al.  Simulating the global atmospheric response to aircraft water vapour emissions and contrails: a first approach using a GCM , 1996 .

[16]  D. Rind,et al.  Modeled impacts of stratospheric ozone and water vapor perturbations with implications for high‐speed civil transport aircraft , 1995 .

[17]  D. Rind,et al.  Climatic effect of water vapor release in the upper troposphere , 1996 .

[18]  Robert Sausen,et al.  Impact of future subsonic aircraft NOx emissions on the atmospheric composition , 1999 .

[19]  Robert Sausen,et al.  Impact of aircraft NOx emissions on tropospheric and stratospheric ozone. part II: 3-D model results , 1998 .

[20]  Robert Sausen,et al.  European scientific assessment of the atmospheric effects of aircraft emissions , 1998 .

[21]  Steven L. Baughcum,et al.  Year 2015 Aircraft Emission Scenario for Scheduled Air Traffic , 1998 .

[22]  A. Schmitt,et al.  Emissions from aviation and their development over time , 1997 .

[23]  R. Giering,et al.  Sensitivity Study of Optimal CO2 Emission Paths Using a Simplified Structural Integrated Assessment Model (SIAM) , 1997 .

[24]  Robert Sausen,et al.  On the cold start problem in transient simulations with coupled atmosphere-ocean models , 1992 .

[25]  Randall R. Friedl,et al.  Atmospheric Effects of Subsonic Aircraft: Interim Assessment Report of the Advanced Subsonic Technology Program , 1997 .

[26]  S. Baughcum,et al.  Scheduled civil aircraft emission inventories for 1992: Database development and analysis , 1996 .

[27]  D. Hauglustaine,et al.  Impact of present aircraft emissions of nitrogen oxides on tropospheric ozone and climate forcing , 1994 .

[28]  Ehsan Masood.  Asian economies lead increase in carbon dioxide emissions , 1997, Nature.

[29]  Thomas Peter,et al.  Impact of aircraft emissions on tropospheric and stratospheric ozone. Part I: chemistry and 2-D model results , 1998 .