(Math)
You think your pond formula was hard, I recently figured how long it would take to raise sea level one inch- by burning fossil fuels at todays world average yearly consumption rate. For every gallon of gas you burn you create slightly more than 1 gallon of water.
It would take almost 2000 years. Less if you include fuels other than oil.
Did the math 3 times. Probably still wrong. Never delt with quintillions before.