Good news. After almost a decade of dramatically falling water levels in the Great Lakes, during which Lake Superior hit a record low, water levels are starting to rebound. For an idea of how low the waters got, here's a pic of a lighthouse in Grand Traverse Bay in 2007
And now the water is coming back.
Huzzah! Welcome news.
But not surprising news.
Great Lakes water levels are cyclical. It goes like this in 10 to 30 year cycles: water goes up, water goes down, water goes up, water goes down, etc. You get the idea. Some time in 2007 we began the "water goes up" part of the cycle, and this year water levels are visibly up such that us laymen can notice.
When water levels had hit dramatic lows, the effect of global warming on the Lakes was an easier sell. Now, as levels rise, the Global Warming Deniers are making "global cooling" cracks and making general asses of themselves as they gleefully point out that rising water levels are proof that Global Warming or "Climate Change" is a bunch of hooey.
First of all, I'm going to explain why global warming is expected to make the Great Lakes levels fall...
The Great Lakes are above sea level. Water is pouring from Lake Superior, to Michigan-Huron, to Erie, to Ontario, and into the Atlantic. So rising oceanic levels from ice cap melting won't increase the Great Lakes. Rather, more water is evaporating from the Great Lakes due to higher temps and less ice cover in the winter. Global Warming will make the Great Lakes levels fall.
And here's why water levels matter...
For nature, rising and falling water levels help to replenish and build wetlands that developed over hundreds of years, nutrient rich and ideal for many species of frogs and birds and the squirming little critters that live there and provide the base of the food chain for the whole ecosystem. Consitently move the water lower and lower, and you have a dried up wetland which isn't much of a wetland at all. And there's no chance for new wetland to take hold and the ecosystem collapses and it's just a damn mess and lots of things die.
It's a problem.
For people, falling water levels introduces a host of nasties: higher shipping costs because boats can't carry as much ore or other stuff without running aground, leading to higher prices for goods. Cooling lines for nuclear power plants are no longer able to draw water which costs millions to fix. Dropping water tables affects agriculture and wells need to be made deeper costing millions of dollars. Add to that the affects of the loss of wetlands, and you get flooding and erosion and reduced commercial fishing yields. Also a damn mess. Also a problem.
So, back to the deniers...
Global warming deniers pull out water level charts, dating back to the 1860s from NOAA to debunk global warming. They say: Falling water levels as evidence of global warming doesn't exist, therefore global warming doesn't exist. See the charts: The blue line is water levels, the red line is the historical average.
You'll probably notice that Lake Michigan and Huron have a descending pattern...but Eerie seems to have a general rising pattern since around the 1980's -- I bring this up later. Ontario hugs the average relatively closely. But on the face of it, on the face, there appears to be no Pan Great Lakes consistency to those charts in terms of a decrease or increase in water levels over the past 150 years.
Just from the charts it seem we're looking at a fairly random set of trends, all lakes taken equally: water goes up, water goes down, water goes up, water goes down.
But the charts don't tell the whole story. For example, Lake Ontario's water levels are fairly regular because they are controlled by the Corps of Engineers. Keep in mind that it's a very small lake compared to Superior, Huron and Lake Michigan, and that's why level controls are possible. The charts show water levels, they don't tell the story.
NOAA (National Oceanic and Atmospheric Administration) tells us why that happens. Water levels come from changes in water supply to the lakes and evaporation from the lakes. Less water coming in and more evaporation: low water. More water coming in and less evaporation: high water.
Easy enough.
One Climate Change denier does some footwork for me, citing a fairly important study on great lakes levels. To slam the door shut on Global Warming "Alarmists" he cites three ACTUAL reasons, found in a press release from a recently completed stud on the causes of great lakes water levels:
Climate change alarmists predicting doomsday scenarios for the Great Lakes are probably not too pleased with the draft report "Impacts on Upper Great Lakes Water Levels: St. Clair River" released May 1, 2009, by the International Joint Commission. The report found that the difference in water levels between Lake Michigan-Huron and Lake Erie of 9 inches between 1962 and 2006 was caused by three factors:
• A change in the conveyance of the St. Clair River, mostly likely caused by a large ice jam that occurred in the mid-1980s.
• Glacial isostatic adjustment (the rebounding of the earth's crust after the melting of the glaciers about 10,000 years ago).
• Changes in climate patterns.
-- Article
Wait...Changes in climate patters?
Couldn't one more or less re-arrange the wording and say "Climate Change"?
Here's the ACTUAL wording of the ACTUAL PRESS RELEASE FOR THE REPORT
A change in the conveyance of the St. Clair River (deepening of the river bed) accounts for about 10 to 12 cm (3.9 to 4.7 in); a relatively dramatic and rapid change in conveyance appears to have occurred in the mid-1980s, possibly resulting from a single event, such as a major ice jam. This change in conveyance resulted in a temporary increase in flows, which returned to pre-change conditions by the end of the decade.
Changes in climatic patterns (less water being supplied to Lake Michigan-Huron and Lake Superior) account for about 9 to 27 cm (3.5 to 10.6 in); this factor has become even more important in recent years, accounting for an estimated 75 percent of the decline between 1996 and 2005.
Glacial isostatic adjustment (the rebounding of the earth’s crust after the retreat of the glaciers) accounts for about 4 cm (about 1.6 in), but varies greatly throughout the basin. For example, this effect is much larger (11 cm or 4.3 in) in Parry Sound on Georgian Bay with respect to the outlet at Lakeport, Michigan, where it is negligible.
Note that our critiquing friend moved that Climatic Change point to the END of his bulleted list...hoping maybe we wouldn't make it down to the third point with our brains still on.
The report itself was from a study aimed at determining if erosion to the mouth of Lake St. Claire was a contributing factor in declining lake levels. They wanted to see if the mouth of Lake St. Claire was widening, becoming a giant DRAIN through which lake levels in Michigan an Huron were emptying faster into Erie. Note the charts above again: Michigan-Huron is trending down, Erie trending up...the theory was that Michigan-Huron were emptying faster into Erie, filling it up.
Their conclusion: Probably not.
In fact, the conclusion was that Climate Change is, by far, the dominant factor, accounting for 75% of the decline in water levels.
The study didn't debunk global warming...it upheld its adverse affects. Warming weather and lowered ice cover is increasing lake evaporation during the winters. And in fact, if you recall that Lake Erie water levels seemed to rise around the 1980s, you'll notice the cause for THAT is attributed to a dramatic "single event" (such as an ice floe) increasing the conveyance of water from Michigan-Huron to Erie in the mid 80s, around the time the charts show greater water levels there. Many climate change deniers point to record high water levels in Michigan-Huron in the 80s, yet the lake has still been consistently well below the historic average for several decades.
Given the information of this new report, the charts start to indicate more of a united pattern downward, with random events altering day to day parallels.
"Climate projections say the lakes will go up and down around a decreasing average," said Don Scavia, director of the University of Michigan's Graham Environmental Sustainability Institute. "The lows will be lower than in the past and the highs will be lower than in the past."
-- Article
Just as our day to day weather patterns at any given moment don't uphold or debunk Global Warming, neither do the day to day water level patterns in the Great Lakes...though climate change deniers are quick to seize on momentary, one off events to underscore their ignorance.
The FULL actual report title "Impacts on Upper Great Lakes Water Levels: Lake St. Claire" can be found here>>
http://pub.iugls.org/...
And on page 39 of the report
In its most recent assessment, the Intergovernmental Panel on Climate Change concluded that
scientific evidence based on well-established theory and observations from long-term monitoring
networks indicates that climate change is occurring, though the effects differ regionally (Brekke
et al., 2009). The Intergovernmental Panel also noted that climate trends since about 1970 have
been driven predominantly by greenhouse gas concentrations in the atmosphere and that this will
continue to be the case in future decades.
That sounds to me like the report very explicitly upholds climate change as a reality. Suck on that Russ Harding, author of that article that pissed me off. Russ Harding of the ultraconservative Mackinac Center for Public Policy. Russ Harding, Climate Change Denier, was the director of Michigan Department of Environmental Quality from 1995 to 2002. What the hell?!?!?