The Great Lakes lack protection. Lawmakers and lawyers have found several holes in Great Lakes legislation. Some existing protections could be challenged as unconstitutional. The global economy might restrict local control over the lakes. Even if the United States and Canada wanted to ban bulk water sales, trade laws might preclude the countries from doing so.
Water scarcity creates conflict.
The disproportionate availability of water in the world will likely lead to a power imbalance. Water could cause war in the 21st century, as oil has in the past. The Great Lakes are fragile. Only 1 percent of their water is renewed annually by rain and runoff. Current lake pollution and the projected water loss created by global warming could be exacerbated by further drains on Great Lakes water.