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.
People need to get it through their thick skulls that we cannot dig ourselves out of this hole without hurting ourselves in the short term. It's decades too fucking late for that. Fixing this will cause unavoidable suffering; not accepting that is going to cause exponentially more suffering. Suffering that has already begun. We as a global society had every opportunity to avoid it, but we chose not to. There is no painless solution anymore. We can all suffer now and mostly make it through to the other side, or we can try to cling to our cushy lives of excess and convenience while the vast majority of us die. Pick one; those are the only choices.