If climate change is truly the harbinger of the apocalypse, and if it needs to be stopped at all costs, then the flight tax would have to be infinite.
On the other hand, if a tree can be planted to capture 1 ton of carbon for 50 cents each, then a flight from NY to Sydney can be offset with $130.[1] That's about $1 per person on a 100-person flight.
Some environmentalists claim that the social cost of carbon is $40 per ton of CO2[2]. That comes out to about $10,500 in taxes for a flight from NY to Sydney. That's basically $100 per person on a 100-person flight, enough to prevent many people from flying.
[1] 53 lbs of CO2 per mile of flight, multiplied by 9,929 miles from NY to Sydney, divided by 2000 lbs/ton, times $0.50 of offset costs per ton
[2] https://www.edf.org/true-cost-carbon-pollution
On the other hand, if a tree can be planted to capture 1 ton of carbon for 50 cents each, then a flight from NY to Sydney can be offset with $130.[1] That's about $1 per person on a 100-person flight.
Some environmentalists claim that the social cost of carbon is $40 per ton of CO2[2]. That comes out to about $10,500 in taxes for a flight from NY to Sydney. That's basically $100 per person on a 100-person flight, enough to prevent many people from flying.
[1] 53 lbs of CO2 per mile of flight, multiplied by 9,929 miles from NY to Sydney, divided by 2000 lbs/ton, times $0.50 of offset costs per ton
[2] https://www.edf.org/true-cost-carbon-pollution