The concoction did generate plenty of carbon dioxide. The problem is that it didn't dissolve into the water. So I looked up a table on carbon dioxide solubility of in water and in water with different salinity.

I do remember that sugar solubility increases tremendously, non-linearly, with increase in temperature while salt an inorganic ionic compound increases more or less linearly with temperature. Gasses on the other hand will decrease in solubility with temperature.

My hypothesis is that carbon dioxide bubble was compressed so small that it clinged to the ground ginger, lemon rind and didn't dissolve into the liquid.

Next round will be to shake the bottle after refrigerating to release carbon dioxide from the ginger and help get it into the water. Also I need to look into the effect of pH of the water. dissolved carbon dioxide forms carbonic acid... Try more lemon juice to reduce pH.

Lemon juice was used not only for flavoring but to help invert regular sugar so that the yeast would have much easier time metabolizing sugar into carbon dioxide.

so too much chemistry for some. Try again today and wait another 24 to 48 hours.
BTW, I modified recipes found in the internet. Alton Brown's ginger ale, and few others.

Once I get it right, I'll try flavoring with mint from our yard, raspberry, marion berries...