I think that “talk” with ChatGPT without any real reason, is something like leave on/powered the engine when waiting at a traffic light, without use the S&S. If you can avoid it, do it.
Everything has a carbon footprint, if you can save a small amount, without lose anything, why not do it?
If 10,000,000 daily requests of 30 words each use the equivalent of 3 months of an average American's carbon footprint, then that means 1 request is equivalent to about .79 milliseconds of average carbon footprint. For an average typing speed of 40 words per minute each request would take on average about .75 seconds for a user to type. So spending time asking GPT questions is about 3 orders of magnitude less carbon intensive than what an American would typically be doing instead during that time.
Everything has a carbon footprint, if you can save a small amount, without lose anything, why not do it?