If you have problems with air bubbles appearing around the stopper as the globe cools, don't fret. Warm up another pot of water, big enough to submerge the entire globe, until it is about the same temperature as the globe. Then remove the globe stopper, and very gently lower the open globe into the pot of warm water, slowly allowing the empty space at its neck to fill from the surrounding fluid. This should be done carefully to avoid agitating the water excessively, and hence causing more glycerine than is necessary to diffuse out of the globe. Once all the bubbles are gone, reinsert the stopper as tightly as possible, and leave the globe in the pot to cool overnight.
Finally, I would really like to add some scale C-notes to the water in my globe to complete the effect, but I haven't been able to come up with any clever way to produce waterproof model currency in an appropriate size. Any suggestions you may have will be welcome in the comments.