I have not traveled beyond Europe for conferences since 2014. Within Europe, I try to travel by train, and group scientific communication trips together to visit several events & institutions while on one trip. This has been made easier by interrail tickets allowing for longer & more flexible trips.
I make exceptions for personal travel (I have elderly & ill parents a 2 hour flight away).
I have been surprised at the level of understanding and support (higher travel costs by rail have to be reimbursed) offered to me in this effort of flying less, and also by the gratitude of often younger colleagues, who welcome someone who “walks the walk”.
I research the resource requirements of economic activity and well-being.