Presented like this, the argument is complete bullshit. Anything we do consumes energy, therefore requires energy to be supplied, production of which has negative side effects, period.

Let's just call it a day on civilization and all (starve to death so that the few survivors can) go back to living in caves or up the trees.

The real questions are, a) how much more energy use are LLMs causing, and b) what value this provides. Just taking this directly, without going into the weeds of meta-level topics like the benefits of investment in compute and energy infrastructure, and how this is critical to solving climate problems - just taking this directly, already this becomes a nothing-burger, because LLMs are by far some of the least questionable ways to use energy humanity has.