I felt guilty after reading this post because I do plan to fly in 2019. I have become mostly vegetarian this year (5 days a week on average) for environmental reasons. So I asked google to compare the two. Here’s what The Guardian newspaper said:
“A vegan diet is probably the single biggest way to reduce your impact on planet Earth, not just greenhouse gases, but global acidification, eutrophication, land use and water use,” said Joseph Poore, at the University of Oxford, UK, who led the research. “It is far bigger than cutting down on your flights or buying an electric car,” he said, as these only cut greenhouse gas emissions.
So I don’t feel quite as guilty, although of course I realize it would be best to not fly and to be vegetarian.