"At present there are no proven technologies capable of large-scale air capture of CO2. It has been suggested that, with strong research and development support and industrial scale pilot projects sustained over decades, costs as low as ∼$500/tC may be achievable [226]. Thermodynamic constraints [227] suggest that this cost estimate may be low. An assessment by the American Physical Society [228] argues that the lowest currently achievable cost, using existing approaches, is much greater ($600/tCO2 or $2200/tC)."
So that's $600+ for an NY-SF round trip - in decades time. Currently we would have no flights at all.