The aviation industry affects climate by modifying the atmosphere’s composition, especially in the upper troposphere and low stratosphere by modifying the atmosphe’s chemistry and adding suspended particles to it. As a particular case of the latter, contrails can be formed in the aircraft’s wake when, given the right temperature and humidity conditions, water vapour condenses and freezes, leaving a trailing cloud that may persist and grow for several hours. Any change in gas and aerosol concentration in the atmosphere affects the flux of solar and infrared radiation, therefore modifying the planet’s energy balance, and ultimately its temperature.
Any change in the radiation flux, known as radiative forcing, shows a roughly linear relationship with the subsequent temperature change of the planet. It is because of this simple relationship that the radiative forcing concept is widely used to quantify the relationship between anthropogenic emissions and Climate Change.
CATE has participated in several research projects aimed at quantifying aviation impacts on climate. Currently we participate, with other 7 partners, in the European project REACT4C, which looks at the possibilities in flight route optimization in order to reduce not only fuel consumption and emissions but to the individual radiative forcing components in order to assess the overall impact on climate. This kind of assessment supports many areas, from operations to policy-making.
Climate research in CATE involves a suite models that simulate the process chain from emission inventories to radiative and temperature impacts on a planetary scale1, including chemistry transport and impacts of linear contrails2.
David S. Lee, David W. Fahey, Piers M. Forster, Peter J. Newton, Ron C.N. Wit, Ling L. Lim, Bethan Owen, Robert Sausen, Aviation and global climate change in the 21st century, Atmospheric Environment, Volume 43, Issues 22-23, July 2009, Pages 3520-3537, ISSN 1352-2310, DOI: 10.1016/j.atmosenv.2009.04.024.