| Popis: |
International climate goals imply reaching net-zero global carbon dioxide (CO2) emissions by roughly mid-century. Among the most difficult emissions to avoid will be those from modern aviation given the industry’s need for energy-dense liquid fuels and the lack of commercially competitive substitutes. Here, we systematically assess pathways to net-zero emissions aviation, exploring the potential contribution of different approaches as well as their social, technical, and economic limits. We find that ambitious reductions in demand for air transport and improvements in the energy efficiency of aircraft might avoid up to 62% and 26%, respectively, of projected business-as-usual aviation emissions in 2050. However, further reductions will depend on replacing fossil jet fuel with very large quantities of net-zero emissions biofuels or synthetic fuels (2.5-21 EJ)—which are currently much more expensive. Our results may inform investments and priorities for innovation by highlighting plausible pathways to net-zero emissions aviation, including the relative potential and trade-offs of changes in behavior, technology, and energy sources. |
