@davidho and controllability … we did a fun little known paper — doi: 10.1002/2014GL062240 — we used a ‘good’ climate model as a surrogate for the real world and future climate response, and an old climate model for a surrogate for a good climate model … I know … it gets very twilight zone …
to explore how controllable SO4 injection above the Arctic might be. We worried buckets that people would accuse us of practicing climate modification. Fortunately, no-one read the paper :o)