PLEASE NOTE:


*

CCNet, 089/2000 - 15 September 2000
-----------------------------------



     "We now have a record from 23,500 feet in the atmosphere (about as
     high as instruments are carried in a weather balloon), one that
     has been preserved naturally, that shows the last 50 years were
     warmer than any other equivalent period in the last 1,000 years."
         -- Lonnie Thompson, Ohio State University


     "We think this is alarming."
          -- Ellen Mosley-Thompson, Ohio State University


     "Temperature measurements from two Greenland Ice Sheet boreholes
     were used to reconstruct the temperature history of the Greenland
     Ice Sheet over the past 50,000 years. The data revealed that
     temperatures on the Greenland Ice Sheet during the Last Glacial
     Maximum (approximately 25,000 years ago) were 23 2 C colder
     than at present. [...] The Medieval Warm Period and the Little Ice
     Age were also documented in the record, with temperatures 1C
     warmer and 0.5-0.7C cooler than at present, respectively. After
     the Little Ice Age, the authors report that 'temperatures reached
     a maximum around 1930 A.D.' and that 'temperatures have decreased
     during the last decades.'"
        -- Review of D. Dahl-Jensen et al. (1998) Past temperatures
           directly from the Greenland Ice Sheet. Science 282: 268-271


(1) 'NEAR-MISS' ASTEROID SNAPPED BY REMOTE CONTROL
     ABC News, 12 September 2000
 
(2) ARIZONA'S MINI-BOOM IN METEORITE RECOVERIES
    Ron Baalke <baalke@jpl.nasa.gov>

(3) NEW CLIMATE SCARE FUELS GLOBAL WARMING HYSTERIA
    Andrew Yee <ayee@nova.astro.utoronto.ca>
 
(4) GREENLAND ICE CORES SHOW EVIDENCE OF MEDIEVAL WARM PERIOD
    Center for the Study of Carbon Dioxide and Global Change

(5) LIVING PROOF THAT HUMAN CULTURES CAN ADAPT TO CLIMATE CHANGE
    Joel Gunn <jdgunn@mindspring.com>
 

========
(1) 'NEAR-MISS' ASTEROID SNAPPED BY REMOTE CONTROL

From ABC News, 12 September 2000
http://www.abc.net.au/science/news/stories/s174370.htm

Near-miss asteroid snapped by remote control
Tuesday, 12 September 2000

Australia's first remote-control telescope at Charles Sturt University,
Bathurst, last week captured a sequence of photographs of a 'near miss'
asteroid as it passed Earth.

Professor David McKinnon operated the telescope by remote control via
the Internet to collect 21 pictures of the one-kilometre-wide asteroid
over 30 minutes as it travelled through space at over 25 kilometres per
second. Dr McKinnon said the asteroid was only 12 times further away
from Earth than the moon and had it hit Earth, it would have made a
crater 250 kilometres in diameter and injected enough dust and material
into the atmosphere to block out the Sun.

"It would have been similar to the event which brought an end to the
dinosaurs", he said. "Life as we know it would have finished." The 21
photographs, each of 30 seconds exposure, were 'stacked', to produce
the accompanying image.

Dr McKinnon attributes the varying brightness of the asteroid, to its uneven
shape and the fact that it is "tumbling" through space, therefore exposing
different sides through time.

Images of the asteroid and other photos taken using the remotely controlled
telescope can be seen here <http://www.csu.edu.au/telescope>.

==============
(2) ARIZONA'S MINI-BOOM IN METEORITE RECOVERIES
 
From Ron Baalke <baalke@jpl.nasa.gov>

News Services
University of Arizona
Tucson, Arizona
 
Contact Information:
David A. Kring, 520-621-2024, kring@lpl.arizona.edu
 
Sep 12, 2000
 
Seven New Meteorites Added to New Online Arizona Meteorite Map

By Lori Stiles
 
Arizona is experiencing a mini-boom in meteorite recoveries, and you
now can view a web-based map that shows where the meteorites hit, what
they look like and how they're classified.
 
The clickable map at http://www.lpl.arizona.edu/SIC/arizona_meteorites/
was created by David A. Kring, students Jake Bailey and Ross Beyer, and
photographer Maria Schuchardt at the University of Arizona Space
Imagery Center.
 
Kring is director of the Meteorite Recovery Program and new director of
the Space Imagery Center at the UA Lunar and Planetary Lab.
 
Scientists know of 39 meteorites found in Arizona during the past 110
years. About a third of these have been found in the past decade. Seven
of those were identified in the past year by the UA Meteorite Recovery
Program (MRP). MRP scientists also identified four others that fell
outside of Arizona.
 
The seven new Arizona meteorites are listed in this month's
Meteoritical Bulletin. They are named Coyote Mountains, Dos Cabezas,
Fish Canyon, Golden Rule, King Tut, Ragged Top and Wildcat Peak.
 
It's no coincidence that more Arizona meteorites are turning up, Kring
says.
 
"It's simply a matter of explaining to people what to look for," he
notes. "We have been making an effort to go out and talk to groups who
are likely to find these things, like Arizona gold prospecting clubs,
and explain what to look for.
 
"Plus, media coverage publicizing the finds is generating more
searches," he adds.
 
Kring says the university meteorite recovery team finds one or two
meteorites in about every 600 samples submitted for study.
 
To check if your suspect meteorite might be the real thing, look at the
series of tips listed in Kring's on-line booklet, "Meteorites and Their
Properties," at http://meteorites.lpl.arizona.edu
 
These tests will filter out 90 percent of the "meteor-wrongs," Kring
notes. If the sample passes these tests, it's time to get an expert
opinion. The public can contact meteorite experts through the UA
Mineral Museum at Flandrau Science Center, the UA Lunar and Planetary
Lab, and Arizona State University's Center for Meteorite Studies.
 
The four non-Arizona meteorites recovered by the UA team during the
past year are one from Roosevelt County, New Mexico, and three from
Saudi Arabia.

================
(3) NEW CLIMATE SCARE FUELS GLOBAL WARMING HYSTERIA

From Andrew Yee <ayee@nova.astro.utoronto.ca>

Ohio State University

Contact:
Ellen Mosley-Thompson, (614) 292-6662; ethompso@magnus.acs.ohio-state.edu
Lonnie Thompson, (614) 292-6652; thompson.3@osu.edu

Written by Earle Holland, (614) 292-8384; holland.8@osu.edu

HIMALAYAN ICE REVEALS CLIMATE WARMING, CATASTROPHIC DROUGHT

COLUMBUS, Ohio -- Ice cores drilled through a glacier more than four
miles up in the Himalayan Mountains have yielded a highly detailed
record of the last 1,000 years of earth's climate in the high Tibetan
Plateau. Based on an analysis of the ice, both the last decade and the
last 50 years were the warmest in 1,000 years.

The core also showed a clear record of at least eight major droughts
caused by a failure of the South Asian Monsoon, the worst of these a
catastrophic seven-year-long dry spell that cost the lives of more than
600,000 people.

The new findings, published in this week's issue of the journal
Science, outline data recovered from three cores drilled through the
Dasuopu Glacier, a two-kilometer-wide ice field that straddles a flat
area on the flank of Xixabangma, a 26,293-foot (8,014-meter) peak on
the southern rim of the Tibetan Plateau. The international team,
including American, Chinese, Peruvian, Russian and Nepalese members,
retrieved the cores during a 10-week, 1997 expedition to the region.
The expedition was supported by the National Science Foundation.

"This is the highest climate record ever retrieved," explained Lonnie
Thompson, professor of geological sciences at Ohio State University and
leader of the expedition, "and it clearly shows a serious warming
during the late 20th Century, one that was caused, at least in part, by
human activity. This is a very compelling story."

For the last 25 years, he and his colleagues have drilled cores from
glaciers and ice caps in some of the most remote parts of the planet in
an effort to recover records of ancient climate. Most current
predictions of global climate change suggest that early signs of
warming will be seen at high elevations where these ice caps exist. So
far, Thompson's work has borne this out.

Researchers at Ohio State's Byrd Polar Research Center and the Chinese
Lanzhou Institute of Glaciology and Geocryology divided the three cores
and were able to identify annual layers for the last 557 years. Samples
from these layers were analyzed for dust concentrations, chemical
composition and oxygen- and hydrogen-isotope ratios.

The isotope ratios let researchers extrapolate the air temperatures
present when the ice was formed.. Dust concentrations give an indication
of dryness or wetness in the region, and the analysis of chlorides,
sulfates and nitrates provide clues about volcanic activity, fossil
fuel burning and desertification.

"We now have a record from 23,500 feet in the atmosphere (about as high
as instruments are carried in a weather balloon), one that has been
preserved naturally, that shows the last 50 years were warmer than any
other equivalent period in the last 1,000 years," Thompson said.

The real surprise came with the monsoon records the core revealed.

The South Asian Monsoon is a major climate event that cycles annually
across India, Pakistan, the southern Himalayan region, the Far East and
reaches as far west as Africa. In the summer, when the Eurasian
continent is warmed by solar radiation, prevailing winds flow offshore,
leaving the region moisture-poor so that drying intensifies. When the
cycle reverses, the winds flow onshore, heavily laden with moisture
from the oceans, and bringing the heavy monsoon rains that drench the
regions. Changes in the monsoon cycle can bring catastrophic flooding
or droughts.

The core data showed that in 1790, the cycle changed, the rains
lessened and drought took hold in the region, a condition that
continued for seven years until 1796 when the monsoons returned.

"That event was major," Thompson said. "It killed more than 600,000
people in one region of India alone. And that was at a time when global
populations were much less than they are today." (Estimates place the
world population in 1800 at 980 million.) "If a similar event occurred
today, the social and economic disruptions would be horrendous," he
said. Current world population is just over 6 billion people.

The ice core record showed other serious monsoon failures and ensuing
droughts in 1876-77, and around 1640, 1590, 1530, 1330, 1280 and 1230,
though none was as devastating as the 1790 event. Thompson's paper
offered no indications of what might have triggered the monsoon
failures.

The data, however, do seem to point to the impact human activities have
had on changing climate in the region. Core samples covering the last
century reveal a four-fold increase in dust trapped in the ice and a
doubling of chloride concentrations, suggesting an increase in both
drying and desertification in the region.

"There is no question in my mind," he said, "that the warming is in
part, if not totally, driven by human activity. I think the evidence
for that is so clear -- not only from this site but also from
Kilimanjaro in Africa." Thompson led an expedition to the ice fields
atop the highest mountain in Africa earlier this year. At least 75
percent of the ice there has disappeared since 1912, caused in part, he
said, by global warming.

=================
(4) GREENLAND ICE CORES SHOW EVIDENCE OF MEDIEVAL WARM PERIOD

From: Center for the Study of Carbon Dioxide and Global Change

Dahl-Jensen, D., Mosegaard, K., Gundestrup, N., Clow, G.D., Johnsen,
S.J., Hansen, A.W. and Balling, N. 1998. Past temperatures directly
from the Greenland Ice Sheet. Science 282: 268-271

Temperature measurements from two Greenland Ice Sheet boreholes were
used to reconstruct the temperature history of the Greenland Ice Sheet
over the past 50,000 years. The data revealed that temperatures on the
Greenland Ice Sheet during the Last Glacial Maximum (approximately
25,000 years ago) were 23 2 C colder than at present. After the
termination of the glacial period, temperatures increased steadily to a
maximum of 2.5C warmer than at present during the Climatic Optimum
(4,000 to 7,000 years ago). The Medieval Warm Period and the Little Ice
Age were also documented in the record, with temperatures 1C warmer
and 0.5-0.7C cooler than at present, respectively. After the Little
Ice Age, the authors report that "temperatures reached a maximum around
1930 A.D." and that "temperatures have decreased during the last
decades."

The results of this study stand in direct contrast to the predictions
of general circulation models (GCMs) that consistently suggest there
should have been a significant warming in high northern latitudes over
the past several decades. They also show large temperature excursions
over the last 10,000 years, when the air's CO2 content was relatively
stable. Both of these observations raise doubts about the ability of
current GCMs to accurately forecast earth's climatic response to the
ongoing rise in the atmosphere's CO2 concentration.

Copyright 2000. Center for the Study of Carbon Dioxide and Global
Change

=============================
* LETTERS TO THE MODERATOR *
=============================

(5) LIVING PROOF THAT HUMAN CULTURES CAN ADAPT TO CLIMATE CHANGE

From Joel Gunn <jdgunn@mindspring.com>
 
Dear Benny,
 
The juxtaposition of the two articles on global warming in your 14sep00
issue raises some interesting questions about methods in the study of
global change. One emphasises the as-yet unfulfilled promise of
similations to predict climate, and the other points out the imporance
of data recognition of rare events in climate history. 
 
I did some geological background research on the occurrence of large El
Ninos for my 1991 Climate Change article that seemed to show that they
occur during transitive periods of rapid global warming, apparently the
case in the current circumstance. 
 
In another incident of global warming, the Medieval Maximum, Native
Americans were able to farm and live settled lifestyles in the American
Great Plains, unlike the roving bison hunters familiar to the first
European observations during the Little Ice Age. During the yet
globally warmer Middle Holocene, the entire Great Plains seems to have
been very sparsely populated and characterized by blowing dust. 
 
In both of these cases, important events that seriously impacted the
course of human life occurred during transitional moments, as did the
reassertion of ice age conditions around the North Atlantic at 12,700
years ago discussing by David Montgomery and Richard Sadler in your
newsletter. 
 
Global circulating models in various experiments take snap shots of hot
world conditions and the indications are that the interiors of
continents would be desertified. Using data based regression models, I
have projected similar hot world conditions. In both cases the models
fail to detect the transitional events and circumstances. In the case
of the simulations, it seems that computing power is still insufficient
to model climate change on a continuous rather that static basis,
something one would hope that similations would come to. The numerical
models are probably inherently unable to deliver such transitional
states such as the large El Ninos during rapid warming or increased
summer rainfall on the High Plains during intermediate episodes of
warming. So far only hard data, in one case geological and the other
human, seem to deliver the quality of the transitional states.  All of
this argues for continued efforts to temper modeling with data from the
remote past when the world was warmer and colder than at present. 
 
Personally I think that the data from human cultures needs to be given
more attention. Data from human cultures are the most sensitive, if
complex to analyze. Humans are the primate order's answer to how to
live in relatively unstable Pleistocene/Recent climates, as nearly 3
millions years of continuous survival, even over survival, indicates. 
 
Joel Gunn

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