The original comment is absolutely correct - "global warming" without any qualification should refer to any planet at any point in space-time. Most of space-time is inaccessible to us, at least in practice, but for example an article titled "Global warming" should at least include the timing, cause(s) and progress of GW on Venus and at various times in the Earth's history when geochmical and fossil evidence indicate that GW probably occurred.
Of course that's only logic. I don't expect it will change the content of this article or lead to most of its current content being moved to e.g. "The debate about contemporary global warming on Earth".