I'm personally a bit ambivalent about questions like this:
- Would there still be wind if Earth had no water?
- How would the Earth look without water in the oceans?
- How would plate tectonics differ if Earth had no water?
Part of me thinks, "Who cares? The earth does have water." But it seems people like asking these questions, and perhaps the answers are relevant to planetary geophysics, or are just interesting to think about.
Counterfactual vs hypothetical
Are they different from (though clearly related to) 'hypothetical' questions, which have been discussed before? I think they're a bit different, though I'm not sure I could articulate the difference... maybe 'hypothetical questions' are about the future, but 'counterfactual' ones are about the past? Or something.
If they're not different, then I guess we should sticking the hypothetical tag on them... or start closing them, because the consensus there seemed to be to disallow them.
If they are different, then do we like or not like? If we like, then do we need a counterfactual tag?
Interestingly, they seem to be banned on History Stack Exchange, and people get a bit cheesed off about them.