Potential of the cryoplane technology to reduce aircraft climate impact: A state-of-the-art assessment

The potential reduction in climate impact due to a switch from kerosene supported aviation to liquid hydrogen (LH2) supported aviation (cryoplanes) is assessed. Different scenarios for a respective gradual technology transition between 2015 and 2050 are provided. State-of-the-art simulations of three-dimensional (3D) radiative forcing (RF) distributions are compiled and complemented for the various agents determining aviation climate impact. They are utilized to quantify the globally averaged transient climate response and respective differences between the transition scenarios. A climate impact reduction of between 15% and 50% in terms of RF is indicated for the cryoplane scenarios at the 2050 time slice, with a best estimate near 30% in case of a swift transition. The respective reduction range is between 5% and 15% in terms of surface temperature change, with a best estimate of about 10%. The environmental benefit of a cryoplane transition further increases if time horizons beyond 2050 are considered. Besides known uncertainties in quantifying aviation climate impacts, crucial limitations of our assessment are insufficient knowledge on contrail cirrus induced by cryoplanes and on the feasibility to produce large amounts of LH2 from renewable energy sources.