adverbs - Usage of particles で and に with ~的

A sentence from JapanesePod 101:

北米とヨーロッパでは通常スカートは女性がはくものと思われているが、世界的には多くの男性がスカートをはく。

In North America and Europe a skirt is thought of as something a woman wears, but in many countries men wear skirts.

I don't see why it's 世界的には rather than 世界的では, especially when では is used in the first clause. で seems to fit both clauses (location of action).

Answer

的 makes 世界 into a 形容動詞 ("na-adjective"), which, when functioning as adverb, turns into ～的に. ～的では is simply ungrammatical.