About those cycles attributed to, you know, 'scientists'.
Lake Aerie and Superior — broke records for water levels this May. Lakes Michigan and Huron could follow suit.
Naturally, climate change is getting the blame. “We are undoubtedly observing the effects of a warming climate in the Great Lakes,” says Richard Rood, a University of Michigan climate scientist.
But just a few years ago, climate scientists were insisting that a warming climate would cause water levels to decline.
In 2008, Science Daily reported on a study that attributed the decline in Great Lakes water levels to global warming. The researchers who conducted the study said that the drop “raised concern because the declines are consistent with many climate change predictions.”
In 2009, Columbia University’s Earth Institute informed us that “most climate models suggest that we may see declines in lake levels over the next 100 years; one suggests that we may see declines of up to 8.2 feet.”
In 2011, the Union of Concern Scientists said that “scientists expect water levels in the Great Lakes to drop in both summer and winter, with the greatest declines occurring in Lakes Huron and Michigan.”
In 2013, the Natural Resources Defense Council said that “it’s no secret that, partially due to climate change, the water levels in the Great Lakes are getting very low.”
That same year, Think Progress reported that “Several different climate models for the Great Lakes region all predict that lake levels will decline over the next century.”
Since the Great Lakes account for 21% of the world’s surface fresh water, these stories were all wrapped in doom-and-gloom scenarios about the impact on drinking water, shipping, recreation, and so on.
The very next year, however, water levels started rising.
So what are scientists saying now? Simple. They’re now claiming that the fall and rise of Great Lakes’ water levels are due to climate change.
“Climate change is driving rapid shifts between high and low water levels on the Great Lakes,” is the new “consensus.”
The truth, of course, is that water levels in the Great Lakes vary over time. And, as a matter of fact, they varied far more in the past than they do now. A U.S. Geological Survey notes that “prehistoric levels exceed modern-day fluctuations.”
Prehistoric Great Lakes Levels
USGS studies show that prehistoric levels of Lake Michigan and Lake Huron exceeded modern-day fluctuations ( Fig. 3). Prehistoric variations in the levels of Lake Michigan have exceeded (by as much as a factor of 2) the 1.6-meter range of fluctuation that spanned the 1964 low level and the 1985-87 high level. One documented high-level episode occurred in the 17th century before the region was widely settled. Lake Superior levels show a similar history, although the range of prehistoric fluctuation exceeded 2 meters in comparison with the modern range of 1.0 meter. Studies by the USGS and the Michigan Sea Grant Program conducted at Bay Mills, Michigan, on the south shore of Lake Superior, near Sault Ste. Marie have documented episodes of low lake levels over the past 2,000 years with mean levels 1.5 meters lower than the present mean level of 183.4 meters. Such episodes of higher and lower levels resulted from natural climate changes in the region. Greater and lesser lake-level fluctuations related to future natural climatic changes are not only possible, but are probable. The impact of possible global warming on the magnitude and frequency of water-level changes remains uncertain.
https://pubs.usgs.gov/fs/FS-022-96/
This revising of specific models, based on new data, is why science works and retains its integrity. The overall predictions (you've cherry-picked one, out of thousands) have proven correct. Revising the hydrologic picture around the Great Lakes shows how the ability to simulate future changes is improving as we get more years of data.
The basic effect, of warming waters, both freshwater and oceanic, has been proven and completely bears out predictions that started being made in the 80s. It's why massive die-offs of coral reefs are taking place right now, and many aquatic species are shifting habitats northward or southward.
Predicting precisely where rising temps will make things drier, or wetter, is much harder and is a work in progress. If it were easy to figure out a complex and chaotic system like weather and ocean currents, it would be the most surprising finding in humam history. Actual scientists are quite conservative in stating the strength of their predictions, which should earn our trust.
The human mind is like an umbrella - it works best when open.
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