Future prospects - Ice Ages and Interglacials: Measurements, Interpretation, and Models - page 351

patterns resulting in lower precipitation and cloudiness might be related to global
warming, but that is only speculation. As Mote and Kaser conclude:
''If the Kibo ice cap is vanishing or growing, reshaping itself into something
different as you read this, glaciology tells us that it's unlikely to be the first or the
last time.''
Hall and Fagre (2003) studied the glaciers at Glacier National Park in
Montana. They pointed out:
''Since its establishment in 1910, Glacier Park has lost most of its glaciers.
Over two-thirds of the estimated 150 glaciers existing in 1850 had disappeared by
1980. Furthermore, over that same time period, the surviving glaciers were
greatly reduced in area.''
In the course of their description Hall and Fagre (2003) pointed out: ''nearly
all the ice masses in Glacier National Park had been undergoing rapid recession
since the turn of the century'' and that ''many of the glaciers in the western
United States that formed during the Little Ice Age began retreating about 1850
to 1855.'' They indicated that mountain glaciers in the park retreated at a modest
rate from 1917 to 1926, retreated at a rapid rate from 1926 to 1942, retreated at a
slower rate after 1942, stopped retreating from 1950 to 1975, and began retreating
again after 1975. In particular, they showed that the Grinnell Glacier has retreated
at a steady pace since 1890, and the Sperry Glacier retreated most between 1910
and 1930. Neither of these retreats can be attributed to greenhouse gases.
Dyurgerov and Meier (1999) estimated the historical retreat of a number of
mountain glaciers during the 20th century. For most glaciers, the data were
restricted to the period 1961-1997. However, eight glaciers were traced back to
1890. They concluded:
''One can conclude that the present-day wastage of glacier volume is, on the
average, part of a continuous process started in or before the 19th century, after
the end of Little Ice Age maximum. Climate became warmer, and glaciers
continued losing volume in response to this change. However, the rate of loss
has been accelerating recently; this suggests that it is not just a simple adjustment
to the end of an 'anomalous' Little Ice Age, as some have claimed.''
Zemp et al. (2009) reported on six decades of annual mass balance data
compiled by the World Glacier Monitoring Service:
''In total, there have been 3,480 annual mass-balance measurements reported
from 228 glaciers around the globe. However, the present dataset is strongly
biased towards the Northern Hemisphere and Europe and there are only 30
'reference' glaciers that have uninterrupted series going back to 1976. The
available data from the six decades indicate a strong ice loss as early as the