Aviation has a range of impacts on climate. While the EU and ICAO have started to address the impacts of CO2 emissions, the other impacts remain unaddressed directly. This short report argues that they should be addressed in line with established European policy as well as by merit of the precautionary principle. In terms of radiative forcing, the non-CO2 climate impacts of aviation are estimated to be approximately as great as those of CO2 emissions. In other words, the cumulative effect of non-CO2 impacts on today’s climate is approximately as great as the cumulative effect of aviation CO2 emissions.