My conscience won't let me do it. I did fly this past June, when I had to be at two conferences four states away on the same day. I would sign the top tier pledge to not fly during the climate emergency, but I think some air travel will be justified, even in a fully-sustainable economy. The lack of decent (fast) railroad service in North America makes it really difficult. It's the frivolous, optional air travel (along with lots of other expressions of rampant consumerism) that's killing our chances at 1.5 degrees.
Read about JD’s work at jdstillwater.earth