Nothing hurts the climate change 'cause' more than it being a 'cause' in the first place. Activism dressed up as science smells, and plenty of people who would otherwise be sympathetic can smell it.
This is exactly the problem. There should be no activism and no causes in science. Each of them implies bias and results in less than ethical practice and unreliable theories.
To ask for rationality and the application of the scientific method results in claims of denialism and instant burying of the opinion.
Scientists are not magical logic faeries separated from the seething mass of culture by a wall of pure mathematics. Science is intertwined in life.
Once you have found that a species is being wiped out, you could stand on the sidelines and measure its decline, watching dispassionately, knowing that you can reach a good solid conclusion about what was killing them when the last dissection is fully documented, or you could chose to interfere and try and prevent the extinction.
However, if what is killing them is well funded human activity, you do not have a hope in hell of interfering successfully without getting political.
The "problem" is that even with the science pointing in a particular direction, if monied interests don't like that direction, they turn it into a political issue with FUD (personal attacks on the scientists rather than the science, stirring up the "science is an affront to God" crowd, etc).
There's a pretty big assumption in there. That the comet is approaching earth and not going to miss it by half a parsec or that the comet is infact a bit of dirt on the lens of the telescope...
All of which need testing first before you start waving your hands around and start saying "WE'RE GOING TO FUCKING DIE - RUN!"
So, if we continue the thought experiment, and say thousands of people have been making observations of the comet for five years and have come to roughly 50% impact probability estimate, with multiple independent methods. And that impact would likely kill maybe a billion people.
And you say it is unacceptable for them to advocate doing anything?
Now, replace the comet watchers with paleoclimate researchers finding out what happened when the planet last time crossed 450 PPM (the other way around).
Inaction is always easier than action, so which way do you think that people will choose?
If we do spend the time, money, and effort to do things like reduce emissions, will we be worse off than we were? Would it not make more sense to use renewable energy resources, and save up the 'easy' sources of energy (oil, coal, etc) for other applications?
To ask for rationality and the application of the scientific method results in claims of denialism and instant burying of the opinion.
That's not acceptable.