| Social Impact of Climate Change:
|
| |
| |
"The
relatively recent droughts described above persisted from a few
years to a few decades. Complex societies can, and do, adapt readily
to interannual-to-decadal fluctuations in water availability, but
more persistent droughts present a different set of challenges and
coping strategies. Multidecadal-to multicentury-scale droughts are
now known to have punctuated the warm climate of the Holocene epoch
[the past 11,700 calendar years before the present (calendar yr
B.P.)]. Furthermore, transitions into and out of these climate shifts
can be very abrupt, occurring in less than a decade. The Holocene
was once thought to have been climatically stable, but detailed
and well-dated paleoclimate records now show that Holocene climate
was punctuated by several widespread cooling events....
How did past
cultures respond to the longer, multicentury-scale climate changes
that punctuated late Holocene climate?"
Peter B. deMenocal
"Cultural
responses to climate change during the late Holocene" |
|
Readings:
|
Harvey Weiss and Ginger Booth |
|
2004 |
ArchaeoSim
v2.0, Java-based simulation program for exploring social and
natural dynamics of Third Millennium BC Subir (northern Mesopotamia).
|
| Harvey
Weiss and Ginger Booth |
2001 |
Simulations
- ArchaeoSim v1.0, Java-based simulation program for exploring
social and natural dynamics of Third Millennium BC Subir (northern
Mesopotamia). |
|
| Supplementary Material |
| |
Abrupt Shifts in Climate Regimes:
 We
are accustomed to thinking of climate change as a gradual, millenia-long
process of slow shifts in temperature and rainfall. Nevertheless, abrupt
climate change has been a fact of history. Individual countries or entire
regions have experienced rapid climate changes that have perturbed agricultural
production, disrupted the continuity of fresh water supplies, and forced
large populations to migrate. While it is rarely a sole cause of political
collapse the wide-scale dislocations that climate changes can engender
have often destabilized political regimes in the course of human history.
In American history, the conditions
of the "dust bowl"
appear now to have been engendered by a climate anomaly that NASA scientists
are beginning to identify as a pattern related to changes
in tropical sea surface temperatures. Local farming practices -- including
the overplowing of land, the destruction of wind-breaking tree cover and
the overtapping of groundwater -- may well have contributed to the severity
of the dust bowl conditions, but the driving force behind this abrupt
shift in weather may have been a climate phenomena whose origins were
thousands of miles away.
In the 1930s the drought and dust
bowl conditions contributed to the mass migration of American farmers
to California, and the impact of the dust bowl was considerable in both
economic and political terms in American history. Since the 1930s many
more people in the world have come to depend upon the seemingly stable
and continuous flow of grain surpluses generated in the American mid west.
If prolongued drought were to return to this mid-continental region --
for whatever reason -- the social impact would be enormous in scope, contributing
to major strains to an international food and grain distribution system
upon which China and many other countries in the Third World have come
to depend. |
| |
Further readings:
| Spencer
Weart |
2003 |
"The
Discovery of Rapid Climate Change," Physics Today,
Vo. 56, 8, (2003),p. 30 ff.
Only within the past decade have researchers warmed to the possibility
of abrupt shifts in Earth's climate. Sometimes, it takes a while to
see what one is not prepared to look for. |
Possible Changes in The "Mediterranean
Weather Delivery System"
| |
 Remember
the space image of the weather delivery system that Professor Weiss
presented in his lecture? Think about the abrupt climate shift events
that he emphasized in the Holocene at the 8.2 kyrbp, the 5.2kyrbp
and the 4.2kyrbp and then consider the following:
Consider the NASA picture and when you have the
dynamic of this west-to-east moving system clearly in mind click
on the following two simulations again and follow through the
logic of what might "flip" in the Atlantic thermohaline
system if certain thresholds (as yet not fully understood) might
be exceeded. This raises the question: What relevance does holocene
climate history have to our contemporary circumstance?
Animation:
A simplified model of global ocean circulation] Abrupt Climate Change
from: Abrupt Climate Change: Should We Be Worried? -
Prepared for a panel on abrupt climate change at the World Economic
Forum Davos, Switzerland, January 27, 2003," Ocean and Climate
Change Institution - Woods Hole Oceanographic Institution, (27 January
2003).
and
Animation:
"If too much fresh water enters the North Atlantic..."
Abrupt Climate Change: Should We Be
Worried? - Prepared for a panel on abrupt climate
change at the World Economic Forum Davos, Switzerland, January 27,
2003," Ocean and Climate Change Institution - Woods Hole Oceanographic
Institution., (27 January 2003). |
|
Week
12
