Keep in mind that that is not the only possible environmental impact. In order to extract such large volumes of water, ecosystems may be damaged.
You are completely off scale. The oceans contain 1.34e+21 L. Humanity uses 1.38e+17J annually. If we take ~10J to move 1Kg 1m up. That means if we spend all our energy on moving sea water, we can move 0.00001% of the ocean up by 1 meter per year.
Any novel ecosystem is close to shore, from those ecosystems most are already damaged by other means.
[1]: https://www.bloomberg.com/news/articles/2021-01-21/french-nu...
[2]: https://www.theguardian.com/world/2013/oct/01/jellyfish-clog...
[3]: https://www.independent.co.uk/news/uk/home-news/hinkley-poin...