I like his approach of stating that these are big claims, but cannot be really evaluated in any meaningful way, as there is no useful public data to look at.
In my opinion this is the main crux of the whole topic. One party (the US government) has a boatload of various quality sensor data that could be studied, but it's classified. As a result nobody can believe anyone's statements as they aren't supported by anything.
Even swapping private planes to passenger ones could save a boatload in carbon emissions. If giving up flying entirely is too much, then at least the regular option would be a lot better.
Those are some big boats. Mr Abramovich's boat is >160m long. Think of driving around in an apartment complex.