How was today's CA IPCC ITSM paper

Confirmation of the particular climate damage

Air traffic emissions have a particular impact on the climate, as they are emitted at great heights and other factors besides CO2 also have an effect here. Hartmut Grassl (Max Planck Institute for Meteorology) and Dietrich Brockhagen (atmosfair) present the current status in a publication. In it, they discuss various methods of comparing the climate damage caused by CO2, contrails, ozone formation and other factors. Based on the data from the IPCC report from 2007, air traffic around the world with all its effects is heating the climate around 1.9 to 4.7 times more than through its CO2 alone. The paper is particularly relevant for the current political debate, as the inclusion of air traffic in emissions trading is currently being discussed in the EU Parliament.

Germanwatch brings excerpts from the paper in German translation.

"This paper calculates the current range of the RFI [Radiative Forcing Index] from the IPCC report from 2007, discusses its importance by comparing it with the GWP-like EWF [Emission Weighting Factor] and examines the statement that long-term CO2 emissions are The RFI is calculated at 1.9-4.7. In contrast to the IPCC report from 1999, the EMF, with a time horizon of Calculated 100 years ago, it is of the same order of magnitude as the RFI, but with a value of approx. 1.2-2.7 it is smaller. This means that the warming effect of the non-CO2 emissions from air traffic (ozone formation, cloud formation) over this long time horizon Both greater and lesser than that of its CO2 emissions. A comparison of the two metrics shows that the justification of the IPCC for the RFI still holds. The EWF has for the duration of its time horizon s a delay in the presentation of the climate impact and so does not indicate the overall climate impact during this phase. It only begins to catch up with this when air traffic emissions decrease. (...) On an RFI basis, the contribution of air traffic to the total human-induced warming through its CO2 emissions amounts to almost 2% and over all its effects a total of around 3% to 7%. (...)

1 Introduction

The climate impact of aircraft exhaust has been the subject of international research since the late 1980s (Schumann et al., 1991). One question is how the climate impact of aircraft exhaust gases is to be assessed at high altitudes of around 9-12 kilometers. The fourth assessment report of the IPCC from 2007 published current results on the various climate effects of air traffic, including ozone build-up and cloud formation. Overall, air traffic causes a greater radiative forcing (RF) than through its pure CO2 emissions (IPCC 2007, WGIII, Chapter 5). (...)

7. Conclusion

(...) The RFI is 1.9-4.7, which is a slight upward expansion compared to the 1999 IPCC report. Even calculated over a time horizon of 100 years, CO2 emissions from air traffic do not necessarily dominate. With values ​​of 1.2-2.7, the EWF (100 years) is overall smaller than the RFI, but in the worst case it is still in the middle of the RFI range. In terms of climate policy, the RFI is more meaningful than the EWF because it better reflects the climate impact of air traffic in the coming decades than the EWF. (...) "

You can find the full paper here.

A current paper by the Federal Environment Agency comes to very similar results: It calculates a value of 3-5 for the RFI and confirms that the RFI is particularly suitable for comparing the climate effects of different sectors of the economy or different areas of transport such as air and road transport . >> Download as a PDF file