AnotherDilbert
SOC-14 1K
The Earth's surface area is 510 000 000 km2, of which 360 000 000 km2 or 360 000 000 000 000 m2 is water. The top mm of water is 360 000 000 000 000 * 0,001 = 360 000 000 000 m3 or ~25 000 000 000 dT water.Here's a design challenge for you:
A cubic mile of ice is about 310,000,000 dtons. Have a specially designed rig jump out to the inner oort cloud and attach to one of the many large chunks of ice floating around. Using thrusters (or conventional rockets using water as propellant) generating a few hundredths to a tenth of a G. Drive the large block of ice into orbit around your planet. Refine fuel from block of ice.
If you really are pulling a cubic mile of water off your primary world every seven years. It won't be too long before someone notices the climate change.
If we skim 310 000 000 dT water for fuel every year it will take us 25 000 000 000 / 310 000 000 ≈ 83 years to lower the oceans 1 mm (1/25").
No-one will notice such puny skimming, ever.
On a tiny world, with tiny oceans we might object on principle. Practically it will not matter.