PALEOCLIMATE
The 4/27/01 issue of
Science
features a
paleoclimatology section containing several articles and papers, a few of which should be of interest to more than specialists
in the field. The contents:
- Erik Stokstad's
Myriad ways to construct past climate, a brief, illustrated overview
of how past temperatures etc. are reconstructed using tree rings,
pollen, geomorphology, ice cores, corals and marine sediments;
- Richard Kerr's The tropics return to the climate system reviews a recent
resurgence in considering the tropics - once thought to be mostly
a passive participant - in long-term climatological changes;
- in
The evolution of climate over the last millennium P.D. Jones et al. look at a millennium's worth of global temperature changes from both measurements
and proxy data, as well as at possible qualitative changes in the North
Atlantic Oscillation and El Nino-Southern Oscillation, two major
quasi-periodic circulation features, over that period;
- Peter deMenocal reviews four case studies documenting
societal changes to drought in
Cultural responses to climate change during the Late Holocene,
combining archaeological and paleoclimatological evidence to
review the cases of the Akkadian collapse (in Mesopotamia around
4200 BP), the Maya collapse (in the Yucatan Peninsula around
1200 BP), the Moche IV-V transformation (in coastal Peru around
1500 BP), and the Tiwanaku (in the Bolivian-Peruvian altiplano
around 1000 BP);
- Margaret Davis and Ruth Shaw's
Range shifts and adaptive responses to Quaternary climate change reviews how tree taxa shifted latitude or elevation
ranges in response to the waxing and waning of ice sheets (and
the accompanying major climate changes) during the Quaternary
(i.e. the last 2 million years);
- in
Sea level change through the last glacial cycle, Kurt Lambeck
and John Chappell review observations of sea level changes over
the last glacial cycle to provide constraints for the timing, rates and
magnitudes of changes in the ice sheets over that cycle; and
- in
Trends, rhythms, and aberrations in global climate 65 Ma to
present, James Zachos et al. document and attempt to discover
the mechanisms for cyclic and non-cyclic changes in the global
climate since the great dinosaur extinction at the K-T boundary
(see
Figure 2 for a pithy graphical summary of the major climatic,
tectonic and biotic events over that period).
More details may follow as motivation dictates.
posted by Steven Baum
5/2/2001 09:10:25 AM |
link
Monday, April 30, 2001
EPIZOOTICS
For those who might think the current European problems with
mad cow and hoof and mouth disease unprecedented, J. R.
McNeill (from Something
New Under the Sun) writes:
Human use of animals often wrought havoc with the animals - sometimes with human consequences. In 1889 the Italian army,
campaigning in Somalia, imported cattle bearing the
rinderpest
virus. It was new to Africa and highly contagious. The density
and mobility of susceptible animals in East Africa led in the 1890s
to the worst epizootic (outbreak of an animal disease) in recorded
history. Millions of cattle died. So did millions of wild buffalo,
antelope, giraffe, and other ruminants. South of the Zambeze
River, perhaps 90 percent of grazing animals succumbed.
Similar proportions died among domestic cattle throughout East
and southeastern Africa. The basis of the pastoral economies
of East and southern Africa evaporated, leading to famine, violence,
desperate migrations, as well as to a spate of religious revivals and
sudden conversions to Christianity and Islam. Among the Masai,
for instance, perhaps two-thirds of the people died.
posted by Steven Baum
4/30/2001 04:34:20 PM |
link
