Out of the Icehouse into the Greenhouse: A Late
Paleozoic Analog for Modern Global Vegetational
Change
Robert A. Gastaldo
Auburn University, AL 36849
William A. DiMichele
Smithsonian Institution, Washington, DC 20506
&
Hermann W. Pfefferkorn
University of Pennsylvania, Philadelphia, PA 19104
A change to global greenhouse conditions following deglaciation occurred during the late
Paleozoic. The deep-past data set preserved in the stratigraphic record can serve as a model
system to understand vegetational responses during this kind of climatic change, especially in the
tropics. No other time in Earth history so mimics the late Cenozoic or provides the long-term
data set from which generalization can be deduced. Two long-term glacial cycles have been
identified in the Permian-Carboniferous time. The waxing and waning of glacier during the height
of either ice age resulted mainly in the spatial displacement of vegetation, and also in minor
variations in tropical climate. Brief intervals of rapid deglaciation at the end of the Middle
Pennsylvanian (Westphalian) and mid-Early Permian (Sakmarian) were accompanied by major
changes in plant assemblages, including extinctions, changes in spatial distribution of plants in the
tropics and temperate zones, and nearly synchronous changes in the structure of vegetation
throughout the globe. Although the plants of the late Paleozoic and the geography of that time
differed entirely from those of today, the rates, geographic distribution, and nature of vegetational
changes can serve as portents of similar patterns in the transition to a modern greenhouse world.
Citation:
GSA TODAY, 1996, v. 6, no. 10, p. 1-7.
