Letter: Great Lake waters go up and go down on an indecipherable trend

There is nothing unusual about that

To the Expositor:

An article featured on the front page of this paper last week, ‘Climate change clear driver of Lake Huron’s high water,’ presented some comments regarding water levels that are interesting to fact check. Particularly in light of comments in the media leading up to the current increase in water levels. Here are a few selected from various newspapers in the USA and here in Ontario: 1996, “warmer air temperatures increases moisture loss, decreases runoff and leads to a decline in lake levels;” 2009, “Big climate change headed Michigan’s way study says, state could see warmer temperatures lower lake levels;” 2017, “Rising temperatures could lower water levels in the lakes.”

Water level records for the Great Lakes are maintained by the Great Lakes Environmental Research Laboratory (part of National Oceanic and Atmospheric Administration). Calling up the graph for Michigan/Huron, there is no obvious trend that can be easily deciphered. The levels go up and they go down and have done so for as long as records have been kept. In addition to the current situation there are a number of level increases that are similar. For instance, from 1926 to 1928 the lake rose three feet or 1.5 feet/year. From 1948 to 1952 it rose 2.8 feet or 0.7 feet/ year. For the period 1964 to 1972 the rate of increase was 0.6 feet per year. The current increase is 0.7 feet/year without considering the current hiatus.

What is even more interesting are the comments attributed to Andrew Gronewold. For example, “when we run various model…. there is no significant signal whether levels might be higher or lower in the future.” In other words, models developed thus far have zero predictive ability.

As an objective look at the graph of lake levels to date show, there is nothing unusual about the levels or the rate of increase for any of the Great Lakes.

A short note about the term “climate change.” It is not a driver of anything. In other words, climate change is not a causal actor it is a “report card.” It is fair to say that a rise in temperature will cause this or that—some positive and some negative. Saying that climate change will do this or that is confusing and inaccurate and is certainly not a driver of high/low water levels.

Shane Desjardins