I don't think there is a short term alternative that isn't simply "Stop travelling, even for work". It takes energy to fly, and we currently only know how to make it work commercially and at the scale we need it with fossil fuels.

It's a hard pill to swallow, and I think we're going to be seeing more of those situations popping up. We're very much used to "Progressing" our problems away and never compromising, making our lives better by making the problems disappear with technology. But we're starting to see some hard barriers in our planets ecology, and we're going to need to sacrifice instead. At least for now.

Plastic is a good example. Coke won't stop making plastic bottles because it's not what consumers want, but of course it's not what consumers want. Consumers, myself included, want the continued march of progress to make our lives better without compromise.