>>13449930Surface area of the ocean is ~361,000,000 Km2
we want to lower sea level by 1cm so that's a volume of 3610 Km3.
Bingham Canyon Mine is the largest open pit mine on the planet, and has been operating for 11 5 years. Assuming it's roughly cone shaped it has a volume of ~3.1 KM3
So in order to drop sea level 1cm you would need to flood 1,164 of the largest open pit mines on the planet, good luck
