The subjunctive mood

Have you ever imagined what would happen if humanity disappeared?

How about 'Have you ever imagined what will happen if human beings are gone?'

lucas21cCould you check the following sentence of the subjunctive mood?Thank you. Have you ever imagined what would happen if humanity disappeared?

But this is not a subjunctive construction; it is a conditional.

The key thing about a subjunctive construction is that it requires the infinitive form of

Thank you for your help. Actually, when I wrote the sentence at first, I was indecisive over the two forms. If both of them are acceptable, could you tell me which one is used more often?

I'd use the past tense forms "would", and "were" to emphasise modal remoteness: "Have you ever imagined what would happen if human beings were gone"?

Essentially, your examples are just two different ways of saying the same thing. There are many others, e.g.:

"Have you ever imagined what it would be like if the human race became extinct".

BillJ