you either need a vector version of the continents and then extrude and Wrap that or you need to do a Displacement with a b/w image of the continents but the edges are really hard to get smooth enough that way (impossible really unless you can stay far enough away). There are vector versions out there somewhere (I don’t know where though).
Here is one way to do the displacement method – it’s not detailed enough for what you want since it doesn’t have country lines but…
3538_earthdisplace.zip