https://ourworldindata.org/emissions-by-sector
All aviation is 1.9% … Private would be a vanishingly small amount of that.
That link does not have information on the contribution of private aviation. You are assuming it.
In this BBC article on What’s the climate impact of private jets you can read that
"Emissions per kilometre travelled [using an airplane] are known to be significantly worse than any other form of transport.
(…)
Private jets generally produce significantly more emissions per passenger than commercial flights."
Yes the BBC article is correct too. Just because CO2 emissions per km travelled are high doesn’t mean they’re statistically relevant in terms of total emissions. All aviation at 1.9% is basically not a meaningful amount of CO2 if you need a 50% reduction.
When weighted for KMs travelled a riding lawn mower is probably worse than a private jet by that logic.
1.9% is significant and meaningful, objectively, mathematically and statistically. It might not feel high to you. But that is your feeling.
And I suspect you are assuming that the path, you think uses the best strategy, to reach 50% reduction on emissions is the only available. Reducing emissions of the persons with most emissions is a valid priority, and these high emitters likely include aviation emmlissions.
