This article investigates whether anticipated technological progress can be expected to offset the CO2 emissions resulting from rapid air traffic growth. Global aviation CO2 emissions projections are examined for eight geographical zones until 2025. Air traffic flows are forecast using a dynamic panel-data econometric model, and then converted into corresponding quantities of air traffic CO2 emissions using specific hypotheses and energy factors. None of our nine scenarios appears compatible with the objective of 450 ppm CO2-eq. recommended by the Intergovernmental Panel on Climate Change. Nor is any compatible with the Panel’s aim of limiting global warming to 3.2 °C.