Low or High, Great Lakes Water Levels Always Blamed on Global Warming

Michigan legislators once tried restricting the sale of bottled water for fear of running out. Today, water levels are once again high and rising.

Last spring, Great Lakes water levels rose above what’s considered average, based on the brief 97-year period that they have been continuously measured. Since then, the lakes have risen enough to cause the sort of concerns associated with high-water periods of the Great Lakes cycle. Those concerns include disappearing beaches, flooding near waterfront dwellings, menacing waves, and even trouble for rescue teams.

Great Lakes water levels rose so quickly compared to other periods that numerous claims – posted on various websites during the most recent trough of the cycle – that low-water levels were evidence of man-made global warming still reside on the Internet. Other residue from the low water level period includes echoes of the political clamor it caused in the mid-2000s.

The 2000 to 2013 low-water level period of the Great Lakes cycle lasted a few years longer than the declines that began in 1926 and 1964. It also became politicized. Former Gov. Jennifer Granholm seized the issue and made it her own.

Legislative hearings were held in the Michigan Capitol, at which testimony attesting to the severity of the alleged crisis was taken. A bevy of laws — some quite draconian – were passed, supposedly to address the situation. A coalition led by the group Clean Water Action demanded that Michigan bottled water companies be required to sell at least 95 percent of their water within the Great Lakes basin.

The Granholm administration imposed a moratorium on bottling plants and restricted the sale of water out of state from Nestle Inc. It eventually backed down.

Geologists, such as those at the United States Geological Survey say that fluctuations of Great Lakes water levels were far more extreme in the past than in modern times. However, these geologists and other experts who have spent their careers studying the sedimentary evidence (going back centuries) of changing water levels were not invited to speak at any legislative hearings.

“It became pretty clear that they weren’t interested in anybody who might disagree with their preconceived position on this and the outcome they were aiming at,” said Sen. David Robertson, R-Grand Blanc, who was a House member when the issue of a possible water shortage in the Great Lakes basin was in the legislative limelight. “It always seemed to me that things like the weather are influenced by forces far beyond what the Legislature can do anything about. Making hasty decisions based on what was happening short-term, when longer-term natural fluctuations were involved, such as occur with Great Lakes water levels, made absolutely no sense, and I said so at the time.”

Throughout the early and mid-2000s, Todd Thompson, then an associate scientist with the Indiana Geological Survey, an institute of Indiana University, was interviewed several times by MIRS newsletter in Lansing. In those interviews Thompson asserted that the variation the Great Lakes were showing was not atypical and that the fall in lake levels from the high levels of 1986 were the same as in the recent previous cycles.

“In the media and politics a lot gets said and written, but the actual data rarely gets shown,” Thompson said in one interview. “I try to give as many talks to groups as possible. I tell them I want to give them a perspective that goes beyond their lifetimes.”

“I'm beginning to think the problem is that we have engineers who don't believe any measurements unless they've taken it themselves in the last six minutes,” Thompson also told MIRS. Conveying his importance of taking the long view, he said, "is an uphill battle.”

In September 2005, the Granholm administration was trying to restrict the ability of the Nestle Ice Mountain water plant in Mecosta County to export its product outside of the Great Lakes basin. Newt Gingrich, former speaker of the U.S. House of Representatives, stopped over in Michigan and criticized what was going on.

“You're surrounded by the largest collection of water in the world,” Gingrich said. “Do you know how ideologically out of touch with reality you are if you've concluded that Michigan could run out of water?”

Geologists say about 4,500 years ago Lake Michigan-Lake Huron had two outlets, one where Port Huron is today and the other close to where Chicago is now located. Between 4,500 and 3,400 years ago, the lake level fell nearly 15 feet and the outlet at what is now Port Huron began handling the entire discharge of the Great Lakes. This marked the beginning of the modern phase of the Great Lakes.

Thompson has written that Lake Michigan-Lake Huron is subject to regular water level cycles that vary between 28 and 37 years. His data shows that from 3,400 years ago to the present, the upper limit of Lake Michigan-Lake Huron reached an elevation of 1.5 to 3.5 feet above the historical average and about 1.5 feet below. Two prominent highs occurred from 2,300 to 3,100 years ago and then from 1,100 to 1,900 years ago. The lowest lake levels of the modern lake phase occurred about 1,000 years ago, corresponding with the medieval warming period, which took place approximately between the years 800 and 1200.

Clean Water Action of Michigan was contacted and asked: In light of the rebound of the Great Lakes water levels, could it now be said that your call to limit bottled water sales outside of the Great Lakes basin was shortsighted?

So far there has been no response.