Climate change and population growth are making the Great Lakes region's role as a global food producer more important as water shortages become more severe in other parts of the world.

"The coming water crisis will affect everyone and everywhere," said Jim Olson, a water-rights lawyer in Traverse City, Mich.

The Great Lakes, one of the world's most abundant collections of fresh water, are positioned to become "ground zero" as water vanishes elsewhere. North America's largest lakes by volume, they hold 20 percent of all fresh surface water on Earth. Their 6 quadrillion gallons are enough to submerge the continental United States in 5 feet of water. They are the source of drinking water for 30 million Americans and 10 million Canadians.

They do not hold as much fresh water as the world's largest lake, Russia's Lake Baikal. But unlike the Siberian lake, the Great Lakes lie in a moderate climate and are accessible for shipping, recreation, tourism, drinking water, agriculture, energy production and manufacturing.

Water management pact

The lakes' usage has drawn more attention in recent years from ­politicians and legal scholars who say Great Lakes water-management laws pale in comparison to those of the American Southwest, where battles over water have been fought for decades.

Scholars believe the region's legal framework is evolving, as ­evidenced by intense negotiations that resulted in the Great Lakes region's first binding water-management compact. The area has traditionally been less irrigated than others. But that is changing with concerns over weather becoming more unpredictable because of ­climate change.

"Farmers are just hedging against bad weather," said Jim Hoorman, an Ohio State cooperative extension agent.

The long-term outlook has the potential to affect everything from shipping to recreation to water quality, as changing food markets worldwide prompt area land to be farmed more intensely. "We are blessed in Ohio with water, but there is a need for a long-term strategy on [better] managing the resource," said Larry Antosch, Ohio Farm Bureau Federation senior director of policy development and environmental policy.

The issue gained more traction recently following the publication of a major essay by Lester R. Brown, president of the Washington-based Earth Policy Institute.

In his paper, Brown notes half of the world's population is in 18 countries that are water-stressed: They are pumping out aquifers faster than rain is replenishing them. That group includes the politically unstable Middle East but also China, India and the United States — the world's top three food ­producers.

Brown theorizes that if the world has now reached what is known as "peak water" — that point at which water will forever be used faster than it is replaced — then the business of growing food will change because it will be more difficult to produce it in water-stressed areas.

One of the most water-stressed parts of the United States is the Great Plains region, where water is being depleted fast from the massive Ogallala aquifer by Texas, Oklahoma, Kansas and Nebraska.

As Great Plains wells dry up, farms in the Great Lakes region and other parts of the Midwest will be under greater pressure to produce.

"We are going to see and are already seeing water-intensive industries move back to the Midwest," said Jim Byrum, Michigan Agri-Business Association ­president.