First, I'm not sure why so many have jumped from "scientists should be responsible for their statements" to "we shouldn't have scientists".
Second: if responsibility leads to miniizing public concern, then is the inverse also true? Because, that was sort of my point. Now, how do we address it?
We made the jump because it's the logical outcome of making people responsible for predicting the future. Why go into a field where a mistake means jail and/or financial ruin? Better to go into finance, where a massive mistake means bonuses. We already don't have enough people going into the sciences. Criminalizing something that isn't a crime for any other profession is a sure-fire way to kill the profession.
And no, the inverse isn't necessarily true. Science is a savage way to make a living. You get known in your field by making a big discovery, or by proving the other guy wrong. Most of the time, it's by proving the other guy wrong. So, for your theory that climatologists all over the world are exaggerating climate change to be true, you first have to get climatologists all over the world to agree to be part of it, then you have to somehow keep younger climatologists from proving you wrong to make a name for themselves.
This would be a conspiracy of literally global proportions.
Now, should we consider criminalizing the behavior of corporations who hire scientists to conduct their own research that, oddly enough, virtually always finds what the corporation wants them to find? Thus muddying the waters.