The inference in your example seems doubtful if not fallacious, but you asked about the grammar, specifically elliptical grammar. The second part of your second example leaves out only "It" but repeats everything else from the first part of the sentence, beyond substituting "globally" for "locally." That works. In your first example, the second part of the sentence leaves a good deal more out. That works fine too if you do not go too far with it; but you did go too far, in leaving out "not," which cannot well go without saying here: the clause's negativity does not survive ellipsis of the negative. I accordingly read the first example (before reading the second) as meaning the thing does not exist locally and so MUST exist globally, or at least elsewhere on the globe.