You're just assuming their inner thoughts. Furthermore most who believe in climate change aren't exactly sacrificing, either. Still flying in airplanes (even private jets), using air conditioning, eating meat, using or pushing fast fashion, etc.

As for an argument, well, experts have been on the wrong side about things like climate predictions, stock predictions, economy, nutrition and so on many times. Even to terrible effect. We replaced fat with trans-fats and sugar, for example. So it's at least fair to be skeptical.

Personally, I'm on the side of science and climate change is a problem we need to solve. And I think we will because we tend to be good about solving slow moving disasters. Besides, optimism and hope about the future is a better strategy than seeding people with fear, doubt and anxiety.