Geoscience Reference
In-Depth Information
Myths, Misinterpretations, and
Misunderstandings of the Deniers
myth
: Plants and animals have been
through this all before.
During the last two
million years there have indeed been at
least seven major swings in temperature, as
indicated by the advances and retreats of
glaciers. The problem is that global change
is happening at a rate that is much more
rapid than any known in the geologic re-
cord. Migration and adjustments to the
changing food supply patterns of plants
and animals often require more time than
is available. The impact of global change on
plants and animals does not happen in iso-
lation. The widespread human destruction
of habitats through deforestation and ag-
riculture is of course greatly adding to the
problem.
myth
: Plants are not as sensitive to tem-
perature control as global change models as-
sume, as indicated by numerous examples of
“out- of- place” plant assemblages.
These “dis-
junct” plant assemblages of cold climate
plants existing in warm climates are com-
mon in the southern United States. One
example is the ifty-one species of alpine
tundra plants high on San Francisco Moun-
tain, Arizona. Another is the occurrence of
Arctic Alpine species found in deep gorges
in the Cape Breton Highlands of Nova Sco-
tia. But rather than indicating a lack of
sensitivity to temperature, these plant as-
semblages are believed to be tiny, isolated
remnants of the ice age forests and grass-
lands that once covered the region.
