How does rising atmospheric CO2 affect marine organisms?

Click to locate material archived on our website by topic


Post-Little Ice Age Histories of Four Icelandic Glaciers
Reference
Caseldine, C.J.  1985.  The extent of some glaciers in northern Iceland during the Little Ice Age and the nature of recent deglaciation.  The Geographical Journal 151: 215-227.

What was done
Lichenometry was used by the author to determine the dates of occurrence of the maximum Little Ice Age extensions of four glaciers in Northern Iceland, as well as their movements subsequent to that time.

What was learned
The maximum Little Ice Age extensions of the four glaciers were reached in 1868, 1885, 1898 and 1917. Since those times, two of the glaciers have continued to retreat through the end of the study period (mid-1980s). The other two glaciers, however, have slowed, stopped and periodically re-advanced. One of them, in fact, advanced 50 meters between 1977 and 1979, 30 more meters between 1979 and 1981, and 25 additional meters between 1981 and 1983. The author notes that the advances appear to occur when mean summer temperature drops below 8-8.5°C, which has occurred several times over the past several decades, following a significant downward trend in summer temperature that followed the broad maximum experienced there in the 1930s and 40s.

What it means
According to conventional wisdom, the Little Ice Age held sway over much of the world until the end of the 19th century, after which it rapidly waned. The more recent advances of some of the glaciers studied by Caseldine, however, suggest that Iceland's climate may not have fully evolved into what in many parts of the world is being hailed as the Modern Warm Period. Could it be that climatic remnants of the Little Ice Age still lurk about the fringes of this North Atlantic island?


Reviewed 16 October 2002