In short, we aren’t on track to an apocalyptic extinction, and the new head is concerned that rhetoric that we are is making people apathetic and paralyzes them from making beneficial actions.
He makes it clear too that this doesn’t mean things are perfectly fine. The world is becoming and will be more dangerous with respect to climate. We’re going to still have serious problems to deal with. The problems just aren’t insurmountable and extinction level.
I’d prefer to stop trying to win over unwinnable people. Whether they join or not, the problem exists. Climate change doesn’t care that we may want to placate the more dense-skulled in society. The problem marches on whether they have changed sides or not.
The science is in, has been in, and continues to be in.
I don’t think there is such a thing as “unwinnable people”. They’re unwinnable from a single conversation with a single person, sure. But they’re not unwinnable if the currently ongoing concerted effort by climate-denying mass media were instead directed towards delivering climate science.
Tldr: the problem isn’t the people who are brainwashed, the problem is the people doing the brainwashing.