[AKrumbach]

> If the author means literally everyone dead, planet gone, then obviously it won't be "apocalyptic", but the science is suggesting it's likely to be really bad.

No, the science doesn't imply that climate change is going to mean literally everyone dead, only a massive cost to maintain things as they are today. Contrawise, Alexandria Ocasio-Cortez said "the world will end" by 2030 if we don't stop climate change. (Source: https://thinkprogress.org/we-dont-have-12-years-to-save-the-...)

So, yes there are people being absolutely, ridiculously, unscientifically hysterical about the effects of climate change. Unscientific alarmism is just as harmful toward efforts to properly manage the global ecology as the unscientific denial of changes.