The contribution of civil aviation to climate change is generally estimated at about five per cent of all human contributions. Roughly two per cent comes from carbon dioxide, while there is considerable scientific uncertainty in the estimates of the other two largest contributors, condensation trails and oxides of nitrogen. Over the past several decades, growth in demand for air travel has been around four to five per cent annually, while annual improvements in fuel efficiency through improved aircraft and engine technologies have been one to two per cent.
If this growth in demand continues in the post-pandemic world, then civil aviation’s contribution to climate change will grow significantly unless additional steps are taken. While biofuels and possibly hydrogen represent potential long-term solutions, nearer term reductions in emissions can be achieved by accelerating aircraft fuel efficiency improvements through new technologies. The U.K., EU, and U.S. are investing heavily in R&D toward such technologies.
Despite the growing public concern caused by aviation’s rising contributions to climate change, the Government of Canada has invested relatively little in research to address aviation’s sustainability. The federally supported Green Aviation Research and Development Network (GARDN), which facilitated collaborative university-industry research, has not been renewed, even though the importance of its work continues to increase.