Klein's article is wonderfully written & well worth reading, but as I noted in a comment, I didn't find it satisfying.
Please, go read Klein's piece first, then the P3 critique.
I particularly agree with this criticism of Klein's "go local" focus:
"Klein’s celebration of the local is somewhat ironic. The whole problem is that our system is incapable of adjusting to global constraints. Devolving more power locally will help many things, but it will not help us develop global policies that work."