You’re basing your whole criticism on two words. Two words! Sorry they didn’t pick the verb you wanted. I’m sure you’d find a different way to dismiss this knowledge if they had.
But let’s break this down. Why the verbiage “can be”?
Climate change is a plus-factor. It exacerbates other things that can cause your death.
Heat waves get worse. Severe weather gets worse. Droughts get worse. Wildfires get worse. Crop failures and famines get worse.
It’s like two people getting infected by Covid. One is 25, the other is 85. Covid *could* cause the death of a 25 year old. But it’s unlikely to, in comparison to an 85 year old.
Let’s say the 85 year old does die of Covid. Did he die *of* Covid or *of* old age?
Well the answer is that he died of both. Or in other words, you can say he died of Covid. Or you can say he died of old age. But the picture isn’t really complete unless you acknowledge how those two things interact.