Future prospects - Ice Ages and Interglacials: Measurements, Interpretation, and Models - page 350

climate periods. Thus, in a simplified manner, one can say that the [periodic]
fluctuations of Alpine glaciers were driven by glacier-hostile (warm/dry) and
glacier-friendly (cool/wet) periods.''

However, they emphasized: ''a detailed examination of historical data suggests
a rather more complex situation.'' They provided examples where ''specific and
varying temperature and precipitation courses during winter and summer'' were
responsible for glacier advance and retreat. In particular, they claimed: ''the LIA
between 1300 and 1850 coincided with wetter summers and colder winters, i.e.,
two factors favorable to glacier extension and higher lake levels.'' They also sug-
gested the NAO index could well influence glacier advance and retreat, and
indicated this may have initiated ''the impressive loss of the alpine glaciers since
the last glacial maximum c. 1850/60.''
Evidence is also available from mountain glacier retreat records. The question
here is whether mountain glacier retreat began before the buildup of CO 2 in the
atmosphere or whether the retreat of glaciers conforms in time with CO 2 buildup.
In the former case, it would appear that glacier retreat might be a natural phe-
nomenon as the LIA waned. In the latter case, it may be due to global warming
induced by greenhouse gases. Kotlyakov (1996) in his extensive survey of glaciers
showed that the rate of mountain glacier retreat did not change substantially from
1900 to 1982. A number of other studies of mountain glacier retreat are summar-
ized by Rapp (2008). The claim made by Al Gore in his film An Inconvenient
Truth that the loss of glaciers on Mt. Kilimanjaro was due to global warming
induced by greenhouse gases has been proven false by Mote and Kaser (2007).
Mote and Kaser (2007) said:

warming fails spectacularly to explain the behavior of the glaciers and
plateau ice on Africa's Kilimanjaro massif, just 3 degrees south of the equator,
and to a lesser extent other tropical glaciers. The disappearing ice cap

'' ...

, which
gets a starring role in An Inconvenient Truth, is not an appropriate poster child for
global climate change. Rather, extensive field work on tropical glaciers

...

... reveals

a more nuanced and interesting story.''

Mote and Kaser went on to point out:

''Another important observation is that the air temperatures measured at
the altitude of the glaciers and ice cap on Kilimanjaro are almost always
substantially below freezing (rarely above 3 C). Thus the air by itself cannot
warm ice to melting by sensible-heat or infrared-heat flux

... ''

The mass balance of ice cover on Kilimanjaro is primarily determined by
precipitation vs. solar-induced sublimation. The reason that Kilimanjaro has been
losing ice cover is that precipitation has decreased and sunlight increased; it has
nothing to do with global warming. It may be possible that changing wind