As a result, there are now numerous web sites that explain that this is just bunk.

Most Global Warming reports claim that the worlds glaciers are shrinking - but 90% of the total ice mass actually growing.

Glaciers are moving rivers of ice - and many (not all) of these are shrinking.

However, over 90% of the Earth's ice is located in non-moving ice caps - and these are increasing mass.

In fact, the reason that glaciers grow or shrink is not well understood and facts related to this should NOT be used to argue either side of Global Warming.

Also, if all the alpine glaciers that are used in these reports completely disappeared, there would be little or no sea level change - there really is not that much ice involved.

Glaciers shrink because the rate of water addition is less than the rate of water loss. This can be caused

• By warming the glacier so that it melts faster
• By reducing the amount of snow added at the top
• By increasing the rate of sublimation (direct loss of water to the atmosphere without melting it first)

Thus, if the amount of snow added to the top of a glacier is reduced, then the glacier will move slower. However, since the leading edge of the glacier continues to melt at the same rate as before, the leading edge will retreat.

There is no sign of any recent global trend towards increased glacier melting

Alpine glaciers are generally shrinking, Scandinavian glaciers are growing, and glaciers in the Caucasus are close to equilibrium for 1980-95.

I have not read this article (because it costs $38), but it is referenced on several other pages - so I will quote those.

Reference

Braithwaite, R.J. 2002. Glacier mass balance: the first 50 years of international monitoring. Progress in Physical Geography 26: 76-95

tsaugust.org is a well written, anti-global warming, site with lots of good data. Glaciers and Global Warming quotes Dr. R. J. Braithwaite - but it isn't clear if all the facts come from that source.

• There are 160,000 glaciers in the world
  • Of those, only 200 have mass balance data for one year or more
  • Of those, only 115 have at least five years of data
  • Of those, only 42 have at least ten years of data

• In an analysis of mass balance in Arctic glaciers, it was found that the rate of loss of mass has decreased in the recent past, a period in which increasing amounts of CO2 should have resulted in faster loss of mass if there were a direct correlation between global warming, CO2 and loss of mass in glaciers.

• Mt Kilimanjaro has lost 80% of its glacier since 1912. Findings recently published by Nature indicate that the loss of forests on Kilimanjaro’s foothills has been the cause of the glaciers demise. The lack of humidity from the forests to replenish and sustain the glacier has resulted in the glacier melting under the equatorial sun. Furthermore, satellite temperature readings taken since 1979 show no increase in the temperature of the troposphere in the Kilimanjaro region. (additional reference)

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The glaciers of Mount Rainier National Park retreat when there is less precipitation (snow fall) and advance when there is more. The last change in glacier positions was reported in 1992 - more than 10 years ago. Some sites claim that these glaciers are currently expanding, but I can not find current data on the USGS site (it also stops at 1992).

This graphic shows how the Mount Rainier glaciers have changed extent over the last 20,000 years.
(As of 09-23-2011, the link is broken and the web archive only has only the first page.)

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Advancing Glacier Coming Close to Blocking Fiord Near Yakutat, Alaska
http://www.usgs.gov/newsroom/article.asp?ID=373
Released: 6/18/2002 

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Glaciers of Glacier Bay, Alaska have been in a state of rapid retreat since the late 1700s

The Harvard Glacier has been advancing since 1905, and possibly earlier. It has advanced at an average rate of nearly 20 m a-1 since 1931, while the adjacent Yale Glacier has retreated at a rate of approximately 50 m a-1 during the same time period.

They have the same snowfield and terminate in the same fjord.

Note that *20 m a-1* means *20 meters per year*. This pdf article shows it as both *m a^-1* and *m a-1*. This article uses both *m/a* and *m/yr*. This is the only conversion I could find

31 m/a (8.5 cm/day)

8.5 cm/day * 365 days/year * 1 m/100 cm = 31.025 m/year

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glacier advancing

photo - Grinnell Glacier in Glacier National Park, Montana
Shows continuous reduction since 1850

Table 1 shows that all significant sea level changes would be caused by melting the Antarctic and Greenland ice sheets ... the rest of the world glaciers would account for only 0.45 meters. The max rise if all the ice melted would be 80.32 meters (263 feet).

Global sea level was about 125 meters below today's sea level at the last glacial maximum about 20,000 years ago (Fairbanks, 1989). [that's about 410 feet]

Sea levels during several previous interglacials were about 3 to as much as 20 meters higher than current sea level. (I interpret this to mean - global warming is normal)

This is absolute proof that temperature and the amount of ice are not always related. This piece of data combined with the loss of the Mt Kilimanjaro glaciers indicates to me that the advance and retreat of glaciers should not be used at all in articles related to Global Warming.

URL: http:// questionable-science.com / Global_Warming / Glaciers.html