Washington, D.C.—The International Council on Clean Transportation released a new analysis of commercial aircraft fuel efficiency from 1960 to 2024, revealing that improvements have stagnated since international CO2 standards took effect in 2020. The study comes as policymakers prepare to gather in Montreal on February 17 to update international aviation standards in support of the sector’s 2050 net-zero CO2 goal. The new working paper, “Fuel burn of new commercial jet aircraft: 1960 to 2024,” finds that the primary cause of the efficiency plateau is a sharp decline in the certification of new, more efficient aircraft types. New type certifications have fallen from a peak of six per year in the late 1990s to less than one per year after 2020. Beyond Boeing’s 777X, manufacturers have not committed to developing additional new aircraft types before 2035. (....)