There is a similar discussion by Stephanie Barnes on LinkedIn

“I have several speaking engagements coming up in the next few weeks, I'm going to share some comments about 3 of them ... The third one, I thought I was speaking at virtually, it's at least a 10-hr flight, several nights in a hotel for a 45-minute presentation and I couldn't justify the risk to my health, the carbon footprint, and the time away from my other commitments (oh, and my expenses weren't being covered, not that that would have changed my mind). Unfortunately, they have declined allowing me to speak virtually, I have to be there in person. I declined the invitation to speak. Now the organiser has to find someone to fill my spot. An unhappy ending for all concerned.”