Seems or seemed

Seems is the correct form. It isn't that the world is/was depopulated. Right now it seems -- present tense.

Hi,

I have a question about the following sentence

"Sometimes, when one person is missing, the whole world seems depopulated"

Since the world can never be depopulated, is it better to use "seemed" instead of seems?

No. Present tense is correct, as you are making a general statement. The problem is that the meaning of the word 'populated' is too extreme,

"Sometimes, when one person is missing, it seems that the whole world is/was/were empty."

If I use 'is', that means I am making a general statement?
If I use 'was' or 'were', am I stressing that the world is actually not empty?

Hi,

"Sometimes, when one person is missing, it seems that the whole world is/was/were empty."

If I use 'is', that means I am making a general statement? Yes.

When I said 'general statement', I meant a statement that is true of all time, ie true of the past, true now, true of the future.

"Sometimes, when one person is missing, it seems that the who

heloOOIf I use 'was' or 'were', am I stressing that the world is actually not empty?

If you really want to emphasize the unreal aspect of an empty world, you can use as if with were.

... it seems as if the whole world were empty.

But it's not at all necessary. It's just fine to leave it as is: ... seems that t