Aviation only makes up about 2% of total global C02 emissions. Hardly even worth worrying about. Results will be much better if resources are focused on the big emitters (road transport, electricity/heating, and manufacturing).
I have read such arguments probably hundreds of times by now. Stuff like "Australia is only 1% of global emissions, why should we suffer the cost of going green?", "China and India produce way more CO2 than the US, the problem is not the US".
It's getting ridiculous; everybody is shifting blame to something or someone else because we all think small chunks and, obviously, each one of those chunks, individually, doesn't contribute much in terms of percentages. If you think this way, nobody will ever get anything done.
In my mid-50s, I started listening to Alan Watts and learning about ancient Indian religions / philosophies. My world-view today is some kind of cross between Zen Buddhism and Advaita Vedanta. I'm a free will skeptic, as well.
While I'm not paralyzed by it, I've come to think that we can't know how any decision we make is going to turn out. We can't know with certainty if doing X is going to be good or bad for us in the long run. All we have are our own estimates of probabilities, and I'm not sure how well we can estimate them, either, honestly.
I also don't know who "I" am, or where I begin or end. In infancy and childhood, I think we come to accept a belief that "we" are individuals, each residing in our physical bodies. Yet I understand the Universe to be a single thing (a quantum field? a simulation?) and so the idea of us being individuals seems a bit off to me. I think we are far more connected and interdependent than we usually recognize.
One good outcome of my world view is that I don't really worry about passing away. A less pleasant outcome is that my world view is so out of the ordinary that I don't often connect with people that I can talk about this with in any serious way.
I'm in exactly the same boat, and I am only 28.