I wouldn't argue that all scientists are selfless that would be silly. I would argue that the average scientist is less selfish than the average politician, yes.
Examine the motivations. Few people go into pure science seeking power or money. Most or all politicians do.
It is not reasonable to ask IF the science should guide our actions. They only alternative is madness.
Right now though, my own limited guess would be that the risk/reward doesn't justify it. The climate is a chaotic system which exemplifies the concept of sensitive dependence upon initial conditions. We could easily kill millions or even billions of people with a little "whoopsie". It might be better to wait until the alternative is worse than that potential cost.
I would, of course, defer to a consensus of experts on the subject if such a thing exists. I am not one.
I don't know. Is that plausible? I find that hard to believe.