'Ethical' flying

Flying, if you are a Green Party activist like, say, Dr David Wall, is usually a bad thing. But there can be occasions when it is a good thing. For example, if you fly to Palestine and then support boycotting Israeli universities, that is a good thing:

"Very proud of Caroline Lucas MEP showing such courage in supporting Palestine, I guess her visits to Palestine (one good excuse for flying!) where she has seen the damage done by Israeli occupation and aftermath have given her a lot of food for thought."

How does this work - is it sort of like planting trees to offset carbon emissions but with passing motions instead of planting trees? The science behind that seems kind of shaky to me.

As, indeed, does the idea that an academic boycott will do anything to help people in Palestine or Israel. Imagine if all the effort which had gone into this malign piece of posturing had instead been spent on doing something useful which might help the Palestinians and Israelis who are working for peace and understanding.