Even in cases where scientists might be making a controversial (to some) statement with a bit too much assuredness (scientists are not beyond the occasional hubris now and then), my experience, having worked with many of them, is that the are rarely if ever acting in bad faith.
There's comments here actively accusing these people of non-nonchalantly and intentionally lying to the public. I'm sorry but this is simply paranoid thinking no matter your view point. There are plenty of academics and scientists whose beliefs I loath, but I have never seriously entertained the thought that these opinions originating from a position of malice.
I only comment about this because it's a bit concerning to me how wide spread this type of irrational paranoia has become. And, to be clear, I'm not attacking people's beliefs to be too "far out there". History has shown enough that strange beliefs can often turn out more correct then not. It's the rage towards people who have dedicated their lives to studying a subject holding a different view that I find concerning.