June 27th, 2019 by Roy W. Spencer, Ph. D.
It is a truism that any observed change in nature will be blamed by some experts on global warming (aka “climate change”, “climate crisis”, “climate emergency”).
When the Great Lakes water levels were unusually low from approximately 2000 through 2012 or so, this was pointed to as evidence that global warming was causing the Great Lakes to dry up.
Take for example this 2012 article from National Geographic, which was accompanied by this startling photo:
The accompanying text called this the “lake bottom”, as if Lake Michigan (which averages 279 feet deep) had somehow dried up.
Then in a matter of two years, low lake levels were replaced with high lake levels. The cause (analysis here) was a combination of unusually high precipitation (contrary to global warming theory) and an unusually cold winter that caused the lakes to mostly freeze over, reducing evaporation.
Now, as of this month (June, 2019), ALL of the Great Lakes have reached record high levels.
Time To Change The Story
So, how shall global warming alarmists explain this observational defiance of their predictions?
Simple! They just invoke “climate weirding”, and claim that the climate emergency has caused water levels to become more erratic, to see-saw, to become more variable!
The trouble is that there is that there is no good evidence in the last 100 years that this is happening. This plot of the four major lake systems (Huron and Michigan are at the same level, connected at the Straits of Mackinac) shows no increased variability since levels have been accurately monitored (data from NOAA Great Lakes Environmental Research Laboratory):
This is just one more example of how unscientific many global warming claims have become. Both weather and climate are nonlinear dynamical systems, capable of producing changes without any ‘forcing’ from increasing CO2 or the Sun. Change is normal.
What is abnormal is blaming every change in nature we don’t like on human activities. That’s what happened in medieval times, when witches were blamed for storms, droughts, etc.
One would hope we progressed beyond that mentality.