The low percentage of plastic is actually millions of tons that affect life in the ocean which is actually capable of transforming CO2. I agree is very complicated to say which one is worse without any data or research. Both are pretty bad anyway, discussion should be how to limit both.
I believe we are going too far and that soon we’ll reach a point of no-return. It’s pretty sad, we could actually change things but only if there was political will and somehow people started listening to what scientists are saying.