🚀 go-pugleaf

I don't think Michaels method going to show the proper perspective of the longitude lines as they wrap around the globe (I'm thinking of a view towards equator, north at the top). 

How about this for longnitude lines. 

Draw a plan view (looking down at north) and drew radial 'spokes' representing the longnitude lines (say 20 deg increments - using transform).  

Duplicate the circle directly below the plan (this will be the view towards the equator) then drag some vertical guides to 'project' the longnitude lines where they intersect the equator (the circle boundary on your plan view) across this new circle. 

Now create a half circle, made from your second circle as Michael suggests above, pulled horizontally by its middle handle until it meets a vertical guide line. Duplicate the half circle and repeat this step for the other guides creating the other longitude lines. 

This is manual, but doesn't take too long at all. The math could be worked out and a nice user friendly script written for it I'm sure. You could record your steps for an action I suppose too. 

Hope this helps. 

-Andy