Full Idea
It does not add to the kinds of necessity to say that p is 'nomologically necessary' iff (the laws of nature → p) is metaphysically necessary. That trick of construction could be pulled for 'feline necessity' (true in all worlds that contain cats).
Gist of Idea
If the laws necessarily imply p, that doesn't give a new 'nomological' necessity
Source
Alexander Bird (Nature's Metaphysics [2007], 3.1.2)
Book Reference
Bird,Alexander: 'Nature's Metaphysics' [OUP 2007], p.48
A Reaction
I love it! Bird seems to think that the only necessity is 'metaphysical' necessity, true in all possible worlds, and he is right. The question arises in modal logic, though, of the accessibility between worlds (which might give degrees of necessity?).