[vanniv]

trillions of kg/yr of anything will effect the environment in some way, since "the environment" is just the emergent properties of all of the things in the earth system and trillions of kg/yr of stuff is a lot of stuff. If you added (or removed) 10^12 kg of water (or literally anything else) to the planet, it would change the environment in detectable ways.

[meindnoch]

>10^12 kg of water

That's exactly 1 km^3 of water. The Earth has 1,386,000,000 km^3 of surface water.

I don't think increasing the amount of water by ~0.00000007% would be noticeable.

[burnished]

It would probably mess up any km^2 of inhabited landmass.