If you study environmental history, it is easy to attend conferences. There is one conference a year in the USA (American Society for Environmental History) and one conference every two years (European Society for Environmental History) somewhere in Europe. During my first holiday-trip by airplane (to Rome), looking at the pollution caused by another airplane when flying over the Alps, my first thought was: what (on earth) am I doing here? So, I decided this would be my last holiday vacation: no New World, no Asia, no Africa. I travel by train (and boat) to my (European) holiday destinations, making traveling part of the holiday.
As for the conferences: two times going to America was enough. Contacts with my colleagues in America are by email and Skype. My recommendation would be to develop Skype meetings much further, including developing ways of informal meetings (over a drink). As for European conferences: I prefer taking the train (and boat). It takes more time, but historically speaking, even going to Finland by train and boat is nowadays easy. It creates the time you need to read books from cover to cover.