2010-2011 Seminar Series
Presents the following seminar:
On the Question of Abrupt Change and
the Emergence of the Sahara Desert
Dr. Sharon Nicholson
Professor of Meteorology
Heinz and Katharina Lettau Professor of Climatology
Department of Earth, Ocean and Atmospheric Science
Florida State University
One
of
the
interesting
questions
that
has
emerged
in
both
climatology
and
ecology
is
how
rapidly
climatic
and
environmental
changes
can
take
place.
Numerous
mathematical
models
have
been
put
forth
to
suggest
that
catastrophic
shifts
in
ecosystems
can
occur
when
critical
transitions
in
the
vegetation
state
are
surpassed.
Many
have
suggested
that
the
emergence
of
the
Sahara
Desert
in
the
mid‐
to
late‐Holocene
is
an
example
of
such
a
catastrophic
shift.
A
sediment
core
off
the
coast
of
West
Africa
has
been
interpreted
as
evidence
that
the
shift
from
savanna
to
barren
desert
occurred
within
a
few
hundred
years
at
approximately
5,000
B.P.
While
climate
models
support
this
possibility,
field
evidence
from
lake
and
pollen
cores
suggests
a
much
more
gradual
transition,
with
the
true
Sahara
emerging
around
3,000
B.P.
When?
Where?
Monday February 28, 3:00 pm – 4:00 pm
PC 438, Charles Perry Bldg, FIU Main Campus