Climate change blamed for Great Lakes decline

[OKIsItJustMe]

http://www.theglobeandmail.com/news/world/climate-change/climate-change-blamed-for-great-lakes-decline/article1401784/

Climate change blamed for Great Lakes decline

Canadian-U.S. study attributes discernible drop in water levels in Huron and Michigan to drier weather

Martin Mittelstaedt

From Wednesday's Globe and Mail Published on Tuesday, Dec. 15, 2009 8:24PM EST Last updated on Thursday, Dec. 17, 2009 2:27AM EST

The water levels of Lake Huron and Lake Michigan have been falling steadily compared with those on Lake Erie, and no one knew why.

But a major report financed by the U.S. and Canadian governments suggests an answer: The fingerprints of climate change are starting to be found in the Great Lakes, the world's largest body of fresh water, causing a discernible drop in their levels.

The report, released Tuesday, estimated that Lake Huron and Lake Michigan have fallen about a quarter metre relative to Lake Erie since the early 1960s, with 40 to 74 per cent of the reduction due to recent changes in precipitation patterns and temperatures.

The alteration in climate is “the most significant factor” in the water level drop and “could be a more substantive issue for the future on the Great Lakes,” said Ted Yuzyk, Canadian co-chair of the International Upper Great Lakes Study Board, which compiled the report.

…

[eppur_se_muova]

1. 3 reads, 1 unrec?

The denial trolls are out early.

[fascisthunter]

2. global deniers should be placed on a piece of ice

somewhere in the Atlantic with no means of escape.

[OKIsItJustMe]

4. Why the Atlantic?

I mean, why not the Pacific or the Arctic?

[fascisthunter]

6. because I'm more familiar with the Atlantic

fine, put them elsewhere, just rid us of these nut cases.

[MercutioATC]

3. I'm not sure whether rain falls on Lake Michigan or Lake Erie qualifies as "climate change".

Just sayin'

[OKIsItJustMe]

5. Does this help you?

http://en.wikipedia.org/wiki/Climate_change

Climate change is a change in the statistical distribution of weather over periods of time that range from decades to millions of years. It can be a change in the average weather or a change in the distribution of weather events around an average (for example, greater or fewer extreme weather events). Climate change may be limited to a specific region, or may occur across the whole Earth.

…

[MercutioATC]

7. Perhaps I should clarify.

Obviously "climate change" is a change in climate, whether global or local.


I question, however, whether rain falls on Lake Michigan or 10 minutes later on Lake Erie is either evidence of some man made problem or anything to be terribly concerned about.

[OKIsItJustMe]

8. We’re not talking about 10 minutes here this is a change lasting decades

…

The report, released Tuesday, estimated that Lake Huron and Lake Michigan have fallen about a quarter metre relative to Lake Erie since the early 1960s, with 40 to 74 per cent of the reduction due to recent changes in precipitation patterns and temperatures.

…

[MercutioATC]

9. For a front moving at 20 knots, Lake Erie is 10 minutes past Lake Michigan.

(at most)

My point is that when rain comes through, whether it falls on Lake Michigan or Lake Erie is a difference of 10 minutes or less. How can that be tied to anything man made?

[reggie the dog]

11. Lake Michigan and Lake Huron are really one lake

they are at the same level, they are called 2 lakes becuase it gets narrow up by Macinac Island. At any rate it has more to do with lakes which had more ice on the before having more evaporation due to less ice cover and less rainfall in the watersheds.

[OKIsItJustMe]

12. I suggest you read the study

You can find it here: http://www.iugls.org/en/home_accueil.htm
http://pub.iugls.org/en/Other_Publications/IUGLS_Final_Report.pdf

[TxRider]

13. Centuries

If it keeps up ancient tree stumps might appear that are down there from last time it was very low.

I would also be interested in the relative effects of uplift of the ground which has been rising for thousands of years in the region.

[OKIsItJustMe]

14. 4 to 5 cm.

…

Overall, the Study Board also found that the difference in water levels between Lake Michigan-Huron and Lake Erie (head difference) declined on average by about 23 cm (9 inches) between 1963 and 2006. They also found that shifts in the earth’s crust as it continues to adjust to the retreat of glaciers account for 4 to 5 cm (1.6 to 2 inches) of the decline in head difference with the apparent resulting decrease in water levels being more pronounced in the Georgian Bay region of eastern Lake Huron.

…

[reggie the dog]

10. not just the rain that falls on the lakes

the rain that falls on the rivers which flow into the lakes as well.

[MercutioATC]

15. OK, so we're looking at a 20-minute window instead of 10.

It's all the same area.

[OKIsItJustMe]

16. I don’t know why I bother…

http://pub.iugls.org/en/Other_Publications/IUGLS_Final_Report.pdf

…

A progressive decline in the lake-to-lake fall or head difference between Lake Michigan-Huron and Lake Erie since measurements of lake levels began in 1860 is well-documented. Figure Ex-1 illustrates how this difference has changed considerably from 1860 to the present day and how it fluctuates from year to year. Records of annual mean water levels recorded at Harbor Beach, Michigan on Lake Huron and Cleveland, Ohio on Lake Erie show that the head difference between the two lakes was about 2.9 metres (m) (9.5 feet ) between 1860 and 1880. The difference then decreased sharply through the turn of the century and generally continued to decline for more than 100 years. In 2008, the head difference was about 1.9 m (6.2 ft). Between 1963 and 2006, the time period on which the Study focused, the head difference declined by about 23 centimetres (cm) (9 inches).

…

Overall, the change in conveyance in the St. Clair River Changing hydroclimatic conditions (particularly a substantial decline in Lake Michigan-Huron Net Total Supplies) have been major factors in the 23 cm (9 inches) decline in the head difference. Hydroclimatic factors accounted for 40 to 74 percent, or about 9 to 17 cm (3.5 to 6.7 inches), of the decline over this full 43-year period. The influence of hydroclimatic factors appears to be increasing in more recent years, however, accounting for 58 to 76 percent of the decline in the 1996-2005 period.

…

Download the report, and skip to chapter 7 "UPPER GREAT LAKES BASIN HYDROCLIMATIC
PATTERNS AND TRENDS"

[MercutioATC]

17. I did read it, I just don't think it's particularly telling.

When we're talking about differences like this, they're microclimate issues, which are susceptible to the smallest of influences.

I just can't get worked up about this.

[OKIsItJustMe]

18. “they're microclimate issues”

Well, I think it’s stretching the definition of “microclimate” to apply it to an entire watershed, however, regardless of that, a change in “local climate,” this significant in one area tends to indicate changes in larger areas. (Don’t you agree?)

You may not care at all about water levels in the Great Lakes; but think of what it suggests for the rest of the world…


It’s a bit like saying, “I don’t care if my neighbor’s well has gone dry. Mine’s fine.” (for now…)

[MercutioATC]

19. I live less than 5 miles from Lake Erie. This is my back yard.

...and I've lived through decades of "The horror! The lake is rising!" or "The end is nigh! Lake Erie's water level is dropping!".


Oddly, both Lake Erie and Cleveland seem to still be here...at about the same relative position as they have been in for decades.


I'm not a denier of climate change, I just don't think this individual issue is particularly distressing.

[OKIsItJustMe]

20. The death of a single canary is not all that distressing

Unless of course you’re a coal miner…

[bhikkhu]

28. If you want a distressing article:

http://dsc.discovery.com/news/2009/01/29/great-lakes-warming.html

...but then again, even that is probably on the order of many decades away in a worst case scenario. I know there are plenty of people who live by the sea and don't consider a few feet of sea level rise to be anything to worry about either. The devil is in the details.

[reggie the dog]

21. Chicago is pretty far from lake Erie.

So is the river which flows into Lake Superior, which then flows into lake michigan/huron. for whatever reason less water is making it into michigan huron than is making it into erie. or more water is evaporating from michigan/huron than erie.

[MercutioATC]

22. 200 miles. That's 8.7 minutes at 20 knots.

...and a 20-knot front is on the slow side.


20 minutes at 20 knots represents a 460-mile range...the distance between Chicago and Buffalo, NY.

[drdtroit]

23. 20 knots = 23 mph, what are you talking about? n/t

[MercutioATC]

26. 1 nautical mile = 1.15 statute miles. 1 knot = 1.15 MPH.

20 knots = 23 MPH.

[OKIsItJustMe]

24. Sorry?

http://en.wikipedia.org/wiki/Knot_(unit)

The knot is a unit of speed equal to one nautical mile per hour, which is equal to exactly 1.852 km/h and approximately 1.151 mph. …

20 knots is about 23 Miles/Hour (not 23 Miles/Minute.)

[reggie the dog]

25. man you got some better grass than I do

20 knots is about 23 mph. not 230 mph.

[MercutioATC]

27. You're absolutely correct. I'm off by a factor of 10.

apologies