The Great Lakes are very low, but the St. Lawrence Seaway links the lakes to the Atlantic Ocean, and the oceans are rising. Is there a way to relieve both problems by bringing some of the ocean water (even though it’s salty) to the Great Lakes?
-- Lillian Arentz
Your proposal has two huge flaws. First is the ecological catastrophe that would result from the introduction of saltwater into the Great Lakes.
Second is the massive and costly engineering task to pump ocean water into the Great Lakes.
The magnitude of the difference in area between the Great Lakes and the world ocean renders your proposal impossible. The area of the world ocean is 1,374 times that of the Great Lakes. Consequently, lowering the ocean by an inch is comparable to raising the level of the Great Lakes by 114 feet!