Air travel is particularly carbon intensive on a per-journey basis and cannot be decarbonized using current technology. We can replace your car with an EV, we can run your air conditioner on renewable electricity, we can swap your gas furnace for a ground-source heat pump, but passenger aviation is going to involve burning tonnes of kerosene for the foreseeable future.
Direct Air Capture can pull carbon out of the atmosphere for ~$200 per tonne. Flying generates about 0.1 tonne per passenger-hour. We can make flying carbon neutral and it'd only be ~20% more expensive.
So about 100 tonnes per flight.
If you account for the impact of the emissions, rather than their weight, air travel is ~6-10% (Because emissions at 30,000 feet have a larger greenhouse effect.)
Since CO2 is mixed in the atmosphere on a timescale short compared to how long it's going to linger there, your argument does not work.