At the risk of siding a little conspiratorial, #5 is secretly what they want.
Most of them don't perceive the devestation of their choices, they just see the simpleminded future of CO2.
It amazes me how easily intelligent people are manipulated into thinking a trace gas vital to life is the single deadliest chemical to our future. It isn't hard to do. Apparently Mr. Huxley was correct when he said 62,400 repetitions make one truth. Sadly, I don't think it takes 62,400, but something like 500.
You can isolate a believer and point out that CO2 isn't a poison at normal levels (or even household levels that typically are 3X what Mauna Loa reports) and that it is absolutely necessary to plant growth. I watched a biologists eyes unglaze when I said this. A person whose specialty surrounded plant life cycles (she was studying ferns at the time) had forgotten what it was that ferns used to "breathe".
I think in the modern age about 5 would probably do it.
Brad, I see huge problems with today's specialisms. Previously even specialists could often be seem to be almost as good and far thinking with broadly based material as they were with their specialism.
Seems to me that is rarer now.
The downside of rarer is that the self percieved lower level of knowledge spread, amongst the most able of the population, leaves them with doubts about their personal knowldege outside their specialism. (Inside is a different psychological and political game ...). So they probably go with the flow. Eaiser to accept what they have been told by someone with an equivalent qualification to their own. The opinion of the other will be accepted since to question implies that they themselves might also be questioned about their speciality - and found 'wanting' for some reasons, not always related to the science they work with.
If that were to happen it would be very uncomfortable - so not worth the risk.
Fortunately there are still a few free thinking exceptions to that principle floating about.