This is another excellent guest post by Muskegon Critic …
Lake Michigan and Huron are within a couple inches of breaking all time low water levels on record, and now climate change is emerging as the leading cause. It works like this:
warmer weather –> less ice cover in the winter –> more evaporation
[We’re are seeing this, real time, in the Great Lakes … see after the fold.]
I’m in the Detroit area right now because my uncle gave my brother and I tickets to the Iowa – Michigan game at the Big House in Ann Arbor. I attended the University of Iowa years ago. My brother, the University of Michigan. Iowa got squished today, but it was a fun time.
Anyway, the point is…I’m not home to take pictures of Mona Lake today. Because if I was home to take pictures of Mona Lake, you’d see markedly low water levels. It would be obvious just looking at it. Long stretches of beach beyond the old breakwater. Boat docks completely on land. A narrowing river where a navigable channel to Lake Michigan used to be.
To folks in the area, it’s obvious that water levels are low. Unusually low. Worryingly low. And for the first time ever, I’m hearing scientists place most of blame squarely on global warming. Here’s Dr. Alan Steinman from the Grand Valley State University Annis Water Resources Laboratory in Muskegon.
There was some concern that the dredging in the St. Clair River had actually increased the size of the “drain at the bottom of the bathtub.” And what the study showed was that the dredging does contribute a couple of inches to the low water levels, but most of it was attributable to changes we’ve had in the climate in the last 15-20 years. There’s been more evaporation and less precipitation, and when you look at that cumulatively that results in lower water levels.
and
As the climate warms, the atmosphere can hold more precipitation, and so, when it does dump it, it dumps out more at once. So we might have a major snowstorm, but the next week it may warm up into the 40s, and it will all melt instead of staying through January, February and March.This is what we call, in scientific literature, the positive feedback loop. That doesn’t mean it has a positive consequence, only that the loop feeds on itself. As the temps warm, as the waters warm, it gets more difficult for ice to form, you have more evaporation, more warming, and that just feeds the cycle. So we have the potential to see more open water, less ice, more evaporation and so on.
The Army Corps of Engineers did an extensive study about lowering water levels and concluded climate is the cause. For a while there was a hypothesis that the Upper Great Lakes were draining water out through Lake St. Claire from over dredging. And while that is certainly an issue, climate is the main cause:
MUSKEGON, MI – When it comes to near record-low water levels in Michigan’s Great Lakes, it’s all about climate.That was the message from the U.S. Army Corps of Engineers Detroit District Office on Wednesday as Great Lakes water-level experts for the federal government announced that Lakes Michigan, Huron and Superior are within an inch or two of setting all-time record lows. The last time the upper lakes had so little water in them was in 1964.
Time to wake up, folks. The things we love are literally evaporating from around us.