There are private jet companies that offer time shares - you pay a percentage of the cost of the plane and a premium per month as well as $$ per flight hour.
If Al Gore is a guest on someone’s plane or has permission to use that plane then technically he doesn’t ‘own’ the jet.
Also, he may have a stake in a company that has a private jet so he wouldn’t ‘own’ that either..
In other words, I wonder if he is lying and tap dancing around the truth.
He thinks nothing of jaunting across the world in a private jet burning a dinosaur an hour.