PLEASE NOTE:
*
CCNet 61/2001 - 27 April 2001
-----------------------------
"However, such impacts may not be a threat to our
civilization in a
couple of hundred years, as we should then have the technological
know-how to detect and deflect such large potentially impacting
bodies
routinely."
--Laurance R. Doyle, SPACE.com, 26 April 2001
"A dramatic life-and-death game of planetary survival is
taking
place inside a gigantic cloud of gas and dust 1,500 light-years
from
Earth, and the outcome could have far-reaching implications for
the number
of planets in our Milky Way galaxy."
--Spaceflight Now, 27 April 2001
"Should one federal agency get sole custody of the universe?
The
question came up in a mysterious little item buried in President
Bush's
budget blueprint. It proposed that federal funding of
ground-based
astronomy research be switched from the National Science
Foundation
to NASA, which funds primarily research conducted in space."
--Kathy Sawyer, Washington Post, 27 April 2001
(1) HEAVENS ON EARTH IN HAGERSVILLE
The Hamilton Spectator Online, 26 April 2001
(2) THE MYSTERIOUS CASE OF CRATER GIORDANO BRUNO
NASA Science News, 27 April 2001
(3) SPACE SHUTTLE EXAMINED FOR DEBRIS IMPACTS
Ron Baalke <baalke@jpl.nasa.gov>
(4) WHAT MAKES A FRIENDLY NEIGHBOURHOOD?
Space.com, 26 April 2001
(5) LIVELY INTEREST IN MSNBC SURVEY ON IMPACTS & HUMAN
EVOLUTION
MSNBC, 27 April 2001
(6) NASA MAY GET NEW ROLE: GOOD OR BAD NEWS FOR U.S. NEO BUDGET?
Washington Post, 27 April 2001
(7) FIRST STEPS OF PLANET GROWTH AND DESTRUCTION WITNESSED
Spaceflight Now, 27 April 2001
(8) LAGGING BEHIND THE SOLAR CYCLE
PhysicsWeb, 24 April 2001
(9) WATCHING SOLAR STRIPTEASE: 5 YEARS OF DISCOVERIES WITH SOHO
HAVE MADE
THE SUN TANSPARENT
European Space, Agency, 27 April 2001
(10) MORE ON THE P/Tr CONTROVERSY
Hermann Burchard <burchar@mail.math.okstate.edu>
(11) THE JORDANIAN FIREBALL EVENT
Andrei Ol'khovatov <olkhovatov@mtu-net.ru>
(12) FINAL AUSTRALIAN SCIENCE TV PROGRAMME LEADS WITH IMPACT
THREAT
Michael Paine <mpaine@tpgi.com.au>
(13) REINVENTING PLATE TECTONICS
Konrad Ebisch <kebisch@zycor.lgc.com>
===========
(1) HEAVENS ON EARTH IN HAGERSVILLE
From The Hamilton Spectator Online, 26 April 2001
http://www.hamiltonspectator.com/news/402801.html
Kate Barlow
The Hamilton Spectator
Scientists are working to unlock the secrets of a
billions-of-years-old
chunk of space metal found in a Hagersville farmer's field.
Almost certainly
a meteorite, the 30-kilogram chunk of iron, nickel and other
minerals is
most likely to have started life as the core of a small doomed
planet formed
early in the history of our solar system.
Meteorites are the only direct evidence, apart from lunar
samples, of the
composition of matter outside Earth. They are gifts from the
solar system
and important in the study of how it was formed.
Richard Herd, curator of the National Meteoric Collection of
Canada at
Natural Resources Canada, says only 58 meteorites have been
identified in
Canada since 1842. Most of the 10,000 tonnes of debris regularly
floating in
space either burns up during its fiery passage through the
atmosphere or
falls into the Earth's oceans to lie forever undisturbed.
"The chances of finding one are relatively rare," said
Herd.
The rock was discovered two years ago by Hagersville farmer
Joseph Mahe
while removing rocks that had emerged in his fields after the
winter freeze.
FULL STORY at http://www.hamiltonspectator.com/news/402801.html
==========
(2) THE MYSTERIOUS CASE OF CRATER GIORDANO BRUNO
From NASA Science News, 27 April 2001
http://science.nasa.gov/headlines/y2001/ast26apr_1.htm?list20392
The Mysterious Case of Crater Giordano Bruno
A band of 12th century sky watchers saw something big hit the
Moon 800 years
ago. Or did they? A new study suggests the event was a meteoritic
trick of
the eye.
April 26, 2001 -- Imagine the shock and amazement of five people
who, in
1178 A.D., spied what appeared to be "fire, hot coals, and
sparks" bursting
forth from the Moon! Apparently something (and it was big) must
have hit
Earth's satellite.
What was it they saw? Until recently many astronomers thought
that
well-chronicled event coincided with the formation of lunar
crater Giordano
Bruno -- the youngest substantial impact feature on the Moon. But
that
popular idea doesn't hold up under scientific scrutiny, says Paul
Withers of
the University of Arizona Lunar and Planetary Laboratory.
Such an impact would have triggered a blizzard-like, week-long
meteor storm
on Earth -- yet there are no accounts of such a storm in any
known
historical record, including the European, Chinese, Arabic,
Japanese and
Korean astronomical archives. Withers reported his analysis and
other tests
of the hypothesis in this month's issue of Meteoritics and
Planetary
Science.
About an hour after sunset on June 18, 1178 A.D., a band of five
eyewitnesses watched as the upper horn of the bright, new
crescent Moon
"suddenly split in two. From the midpoint of this division a
flaming torch
sprang up, spewing out . . . fire, hot coals and sparks. . .The
body of the
moon, which was below writhed. . .throbbed like a wounded
snake." The
phenomenon recurred another dozen times or more, the witnesses
reported.
A geologist suggested in 1976 that this account is consistent
with the
location and age of the 22-kilometer (14-mile) lunar crater
Giordano Bruno,
the youngest crater of its size or larger on the Moon.
Based on the size of the crater, it must have been a one-to-three
kilometer
wide (a half-mile to almost 2-mile wide) asteroid that blasted
Giordano
Bruno into the Moon's northeast limb. Such an impact on the Earth
would be
"civilization threatening" -- so it is important to
know if such an event
happened on the Moon less than a millennium ago, Withers noted.
The impact would have launched 10 million tons of ejecta into the
Earth's
atmosphere in the following week, previous studies have shown. In
the
Meteoritics article, Withers reports his calculations on the
properties of
the subsequent meteor storm.
Left: The impact of a meteorite large enough to form Giordano
Bruno would
have unleashed a major meteor storm, Withers calculated,
comparable to the
1966 Leonids meteor shower pictured here. (During the '66 storm,
as many as
100,000 meteors per hour were recorded in some locations.) [click
on the
picture for more information on the '66 Leonids meteor storm]
"I calculate that this would cause a week-long meteor storm
comparable to
the peak of the 1966 Leonids," he sad. Ten million tons of
rock showering
the entire Earth as pieces of ejecta about a centimeter across
(inch-sized
fragments) for a week is equivalent to 50,000 meteors each hour.
"And they would be very bright, very easy to see, at
magnitude 1 or
magnitude 2. It would have been a spectacular sight to see!
Everyone around
the world would have had the opportunity to see the best
fireworks show in
history," Withers said.
Yet no vigilant 12th century sky watcher reported such a storm.
So what did the witnessess see that the Canterbury monk recorded?
"I think they happened to be at the right place at the right
time to look up
in the sky and see a meteor that was directly in front of the
moon, coming
straight towards them," Withers said. This idea was strongly
suggested by
others in a 1977 scientific paper.
Right: Video footage of a meteor streaking through the atmosphere
during the
2000 Leonid meteor shower, captured by George Varros of Mount
Airy, MD.
Withers believes those five ancient sky-watchers might have seen
the fiery
display of such a meteor traveling along their line of sight
rather than an
impact on the moon.
"And it was a pretty spectacular meteor that burst into
flames in the
Earth's atmosphere -- fizzling, bubbling, and spluttering. If you
were in
the right one-to-two kilometer patch on Earth's surface, you'd
get the
perfect geometry," he said. "That would explain why
only five people are
recorded to have seen it.
"Imagine being in Canterbury on that June evening and seeing
the moon
convulse and spray hot, molten rock into space, " Withers
added. "The
memories of it would live with you for the rest of your
life."
===========
(3) SPACE SHUTTLE EXAMINED FOR DEBRIS IMPACTS
From Ron Baalke <baalke@jpl.nasa.gov>
[From April 2001 issue of ORBITAL DEBRIS QUARTERLY NEWS, NASA JSC
http://www.orbitaldebris.jsc.nasa.gov/newsletter/v6i2/v6i2.html#news4]
ISS Space Shuttles Examined for Debris Impacts
Two Space Shuttles, Discovery (OV-103) and Endeavour (OV-105),
have recently
been examined for orbital debris and meteoroid impacts following
missions to
the International Space Station (ISS) late last year. Both
exhibited
numerous impacts on a variety of inspected orbiter surfaces,
covering more than 200 m2.
Discovery visited ISS last year on the STS-92 mission for seven
days of its
13-day flight in October 2000. A total of 38 impacts were
identified on the
orbiter window thermal panes from orbital debris (9), meteoroid
(7), and
unknown (22) particles. The largest impact feature with a
diameter of nearly
1 cm was apparently caused by collision with a small paint
particle. Three
of Discovery's thermal panes were subsequently replaced.
Six impacts (3 orbital debris, 1 meteoroid, and 2 unknown) were
found on the
radiators with three of these achieving penetration. The
largest radiator
impact site was approximately three-quarters of a millimeter in
extent and
was caused by a meteoroid strike. Four other impacts were
also discovered: three on the flexible reusable surface
insulation (FRSI)
covering the external payload bay doors and one on the vertical
stabilizer.
Of these, two were meteoroids, one was orbital debris, and one
was of
unknown material.
In December Endeavour conducted the 11-day STS-97 mission, which
again
included seven days docked to ISS. Although the number of
identified window
impacts decreased to 30, the number of impacts to the radiators
and the FRSI
(12 and 6, respectively) actually increased compared to the
longer duration
STS-92. A total of two windows were replaced. Of the
12 radiator impacts,
only one penetrated the thin aluminum sheet, but two struck the
silver-teflon-aluminum doubler installed recently to protect the
radiator
coolant loops. Four additional impact sites were found on
the leading edges
of the orbiter wings, two from orbital debris particles and two
from unknown
sources.
Overall, the number of identified impactors of all sizes is
roughly evenly
divided between orbital debris and meteoroids. However, a
significant
number of impactors cannot be identified by type, particularly
for the
smaller window strikes. Complete inspection details are provided
in STS-92
Orbiter Meteoroid/Orbital Debris Impact Damage Analysis,
JSC-29318, January
2001, and STS-97 Orbiter Meteoroid/Orbital Debris Impact Damage
Analysis,
JSC-29373, March 2001.
*****
A related technical article "International Space Station
Debris Avoidance
Operations" is available in the same issue of the newsletter
at
http://www.orbitaldebris.jsc.nasa.gov/newsletter/v6i2/v6i2-3.html#project_reviews
.
==========
(4) WHAT MAKES A FRIENDLY NEIGHBOURHOOD?
Frpm Space.com, 26 April 2001
http://www.space.com/searchforlife/seti_circumstellar_010426.html
Circumstellar Habitable Zones V: Planning Far Ahead
By Laurance R. Doyle
Special to SPACE.com
In a previous article we talked about the possible impact of a
comet or
asteroid on Earth. This has happened before -- certainly at the
Cretaceous-Tertiary boundary when the dinosaurs became extinct
along with
many other species.
The main problem (besides tidal waves a half-mile high and huge
areas of
burning forests) was that the dust thrown up in the atmosphere
blocked out
the Sun's light for an extensive time. Our planet runs on
photosynthesis.
However, such impacts may not be a threat to our civilization in
a couple of
hundred years, as we should then have the technological know-how
to detect
and deflect such large potentially impacting bodies routinely.
Of greater long-term concern are: the evolution of the Sun, the
Moon's
stabilizing influence and the evolution of nearby giant stars, as
well as
events on an intergalactic scale.
FULL ASTORY at
http://www.space.com/searchforlife/seti_circumstellar_010426.html
=========
(5) LIVELY INTEREST IN MSNBC SURVEY ON IMPACTS & HUMAN
EVOLUTION
From MSNBC, 27 April 2001
http://www.msnbc.com/news/563983.asp
Do you think asteroid or comet impacts may have influenced
hominid
evolution?
* 5248 responses
Such impacts had no effect on human societies. 10%
Such impacts could have affected societies, but they didn't play
a role in
the rise of Homo sapiens. 21%
Such impacts could have played a role in eliminating hominid
species. 55%
None of the above. 14%
============
(6) NASA MAY GET NEW ROLE: GOOD OR BAD NEWS FOR U.S. NEO BUDGET?
From The Washington Post, 27 April 2001
http://washingtonpost.com/wp-dyn/articles/A7756-2001Apr26.html
By Kathy Sawyer
Washington Post Staff Writer
Friday, April 27, 2001; Page A21
Should one federal agency get sole custody of the universe?
The question came up in a mysterious little item buried in
President Bush's
budget blueprint. It proposed that federal funding of
ground-based astronomy
research be switched from the National Science Foundation to
NASA, which
funds primarily research conducted in space.
FULL STORY at http://washingtonpost.com/wp-dyn/articles/A7756-2001Apr26.html
=========
(7) FIRST STEPS OF PLANET GROWTH AND DESTRUCTION WITNESSED
From Spaceflight Now, 27 April 2001
http://spaceflightnow.com/news/n0104/27survivor/
A dramatic life-and-death game of planetary survival is taking
place inside
a gigantic cloud of gas and dust 1,500 light-years from Earth,
and the
outcome could have far-reaching implications for the number of
planets in
our Milky Way galaxy.
The good news is that NASA's Hubble Space Telescope is giving
astronomers
the first direct visual evidence for the growth of planet
"building blocks"
inside dust disks around dozens of stars in the giant Orion
Nebula - the
nearest, large "star-factory" to Earth.
The bad news is that other observations suggest that any
fledgling planets
must try to quickly "beat the clock" by forming before
they are evaporated
away by a blistering flood of radiation from the nebula's
brightest star.
Called Theta 1 Orionis C, the star is part of the nebula's
central Trapezium
cluster and is visible through a small telescope.
In new research published today in Science Magazine, John Bally
of the
University of Colorado in Boulder and Henry Throop of the
Southwest Research
Institute, also in Boulder, used Hubble to assess if planets were
beginning
to grow in million-year-old dusty disks in Orion.
FULL STORY at http://spaceflightnow.com/news/n0104/27survivor/
=========
(8) LAGGING BEHIND THE SOLAR CYCLE
From PhysicsWeb, 24 April 2001
http://physicsweb.org/article/news/05/4/11
[26 Apr 2001] The intensity of galactic cosmic rays measured on
Earth is
related to the Sun's cycle of activity, which is well known by
astronomers.
The solar magnetic field flips every 11 years and the number of
sunspots and
'coronal mass ejections' rises and falls twice in each complete
22-year
cycle. The cosmic ray intensity on Earth also peaks twice every
22 years in
time with the solar cycle. Now two US astronomers have discovered
a quirk in
this pattern - and they believe that drifting coronal mass
ejections could
be to blame (E W Cliver and A G Ling 2001 Astrophys. J. Lett. 551
L189).
Edward Cliver, of the Air Force Research Laboratory in
Massachusetts, and
Alan Ling, of Redex Inc in Massachusetts, compared numbers of
sunspots -
dark patches on the disk of the sun caused by local magnetic
fields - and
measurements of galactic cosmic rays dating back to 1951. The
sharp fall in
cosmic ray intensity that occurs every 11-years is closely
related to the
rise in the number of sunspots. "We were studying this
relationship when we
noticed that the cosmic ray curve lagged behind the rise in the
number of
sunspots by about a year - but only during alternate solar
cycles", Cliver
told PhysicsWeb. In the intervening cycles, the two trends occur
almost
simultaneously.
The researchers suspect that the alternating pattern is rooted in
the
reversal of the Sun's magnetic field every 11 years. They propose
that
cosmic rays preferentially approach the Sun from the direction of
its poles
when the magnetic field lines are pointing out of the Northern
hemisphere.
When the magnetic field flips, cosmic rays tend to approach
equatorial
regions of the Sun. But astronomers also know that coronal mass
ejections
(CMEs) - colossal streams of gas that erupt from the Sun's
surface - tend to
occur close to the Sun's equator early in the solar cycle, and
later migrate
towards the poles.
Cliver and Ling propose that when cosmic rays impinge on the
solar poles
early in an 11-year cycle, they do not encounter CMEs. But cosmic
rays do
meet CMEs when they approach the equator at this time in the
solar cycle.
This means that the interaction of cosmic rays with the strong
magnetic
fields of CMEs affects the intensity of cosmic rays on Earth.
"This would
account for the systematic lag we observed", says Cliver. As
the CMEs drift
polewards about a year into the cycle, the cosmic ray profile
returns to
normal.
There are many uncertainties inherent in predicting long-term
trends from
relatively short-term measurements, as Cliver and Ling point out.
But the
pattern is clearly evident from the data so far.
©IOP Publishing Ltd 2001.
=========
(9) WATCHING SOLAR STRIPTEASE: 5 YEARS OF DISCOVERIES WITH SOHO
HAVE MADE
THE SUN TANSPARENT
From European Space, Agency, 27 April 2001
http://sci.esa.int/content/news/index.cfm?aid=1&cid=1&oid=26888
27-Apr-2001 Anyone troubled by storms on the Sun will now have an
extra
week's early warning of eruption risks, by courtesy of the SOHO
spacecraft.
Teams in France and the USA have found two different ways of
detecting
activity on the Sun's far side, before it swings into view from
the Earth.
SOHO's SWAN instrument sees ultraviolet rays sweeping like a
lighthouse beam
across interplanetary gas beyond the Sun, while the MDI
instrument peers
right through the Sun to locate hidden sunspots and their active
regions.
From today, both teams are making their observations available
routinely to
everyone, including the forecasters of space weather.
The announcement of these new far-side services coincides with
the
celebration of Sun-Earth Day 2001, by the European Space Agency,
NASA and
other agencies. It also marks the fifth anniversary of the
commissioning of
the European-built SOHO, in April 1996, and the formal start at
that time of
the observations with a dozen sets of clever solar instruments.
European and
US scientific teams contributed the instruments to this project
of
international cooperation between ESA and NASA.
"What started as unusual research has become an everyday
tool," notes
Jean-Loup Bertaux of the CNRS Service d'Aéronomie near Paris,
who leads the
French-Finnish team responsible for the SWAN instrument. "We
should no
longer be taken by surprise by highly active regions that
suddenly come into
view as the Sun rotates."
The Sun takes roughly four weeks to turn completely around on its
axis, but
active regions can appear and grow in only a few days. So until
two years
ago, no one had any way of telling when an active region might
come 'around
the corner' - perhaps blazing away with eruptions as soon as it
appeared. If
an active region can be detected in the middle of the far side it
will
appear on the eastern (left-hand) side of the visible disk about
seven days
later. The SWAN team announced the telltale ultraviolet
observations in June
1999.
In March 2000 Charles Lindsey of Tucson, Arizona, and Doug Braun
of Boulder,
Colorado, reported that they had detected, with SOHO's MDI, sound
waves
reflected from far-side sunspots. Speeded by the intense magnetic
fields
associated with sunspot regions, the sound waves arrived a few
seconds early
at the Sun's near-side face, compared with sound waves from
sunspot-free
regions. Decoding MDI data from a million points on the Sun's
near side, to
obtain an impression of the far side, uses a technique called
helioseismic
holography and requires a powerful computer.
Both discoveries were made retrospectively from SOHO's archives.
Since then
teams have streamlined their data gathering and analyses to the
point where
they can offer routine long-range forecasts of intense solar
activity based
on far-side foresight. The techniques are complementary, with MDI
seeing the
sunspot regions and SWAN reporting how active they are.
"When we started work with SOHO five years ago, most experts
thought it
would be impossible to see right through the Sun," comments
Philip Scherrer
of Stanford University, principal investigator for the MDI
instrument. "Now
we do it regularly in real time. For practical purposes we've
made the Sun
transparent."
Although conceived for scientific research, SOHO has proved
invaluable as a
watchdog for spotting sunstorms. Forecasters already rely heavily
on SOHO's
round-the-clock observations of flares and mass ejections that
can have
harmful effects on satellites, power lines and other
technological systems.
The new long-range, far-side forecasts may be especially useful
for
scheduling manned space operations, during which astronauts might
be exposed
to dangerous particles from solar explosions.
Watching the solar striptease
SOHO examines the Sun from a vantage point 1.5 million kilometres
out, on
the sunward side of the Earth. Its instruments probe the Sun from
its
nuclear core, through its turbulent interior and stormy
atmosphere, and all
the way out to the Earth's orbit and beyond, where a non-stop
stream of
atomic nuclei and electrons travels outwards as the solar wind.
To the naked
eye the Sun looks calm and unchanging, but for SOHO it has
performed a
dramatic striptease. Here are just ten of the revelations.
The Sun's surprising heart beat. Currents of gas far beneath the
visible
surface speed up and slacken again every 16 months - a wholly
unexpected
pulse-rate. It was detected by combining data from SOHO and a
US-led network
of ground stations called GONG.
Brighter sunbeams. Watching minute by minute and year by year,
SOHO has seen
the Sun brighten, as expected, by 0.1 per cent while the count of
sunspots
increased during 1996-2000. By studying the variations in detail,
scientists
estimate that high-energy ultraviolet rays from the Sun have
become 3 per
cent stronger over the past 300 years.
Eruptions coming our way. Most of the explosive outbursts of gas
from the
Sun, called coronal mass ejections, miss the Earth. Only SOHO can
reliably
identify those heading in our direction, by linking expanding
haloes around
the Sun to shocks seen in the Earth-facing atmosphere. Engineers
then have
2-3 days' warning of possible effects in the Earth's vicinity.
Thousands of explosions every day. A reason why the Sun's
atmosphere is far
hotter than its visible surface is a non-stop succession of small
explosions, observed by SOHO. They result from a continual
rearrangement of
tangled magnetic fields.
The sources of the solar wind. SOHO sees gas leaking from the
corners of a
magnetic honeycomb of gas bubbles, mainly in polar regions, to
supply a fast
solar wind. Nearer the Sun's equator, a slow wind escapes from
the edges of
wedge-shaped features called helmets.
Accelerating the solar wind. Charged atoms feeding the fast wind
gain speed
very rapidly - evidently driven by strong magnetic waves in the
Sun's outer
atmosphere. Similar magnetic waves may accelerate the slow wind
too,
although many mass ejections also contribute to it.
Elements in the solar wind. SOHO detected phosphorus, chlorine,
potassium,
titanium, chromium and nickel for the first time, and previously
unseen
isotopes of six commoner elements. These give clues to conditions
on the
Sun, and also to Solar-System history.
Gigantic sunquakes. After a solar flare, SOHO sees waves rushing
across the
Sun's visible surface, like the ripples seen when a stone falls
into a pond.
One such event was judged to be 40 000 times more energetic than
the San
Francisco earthquake of 1906.
Huge solar tornadoes. SOHO discovered tornadoes as wide as
Africa, with hot
gas spiralling outwards from the polar regions of the Sun.
Typical wind
speeds of 50 000 kilometres per hour can become ten times faster
in gusts.
The alien breeze. A wind of gas from the stars blows through the
Solar
System, and the solar wind fights it. SOHO has fixed its
direction (from the
Ophiuchus constellation) and its speed (21 km/s) more accurately.
Some facts and figures about SOHO
With scientists from 62 institutes in 15 countries, in the teams
that
provide and operate the instruments, and with industries in 15
countries
contributing to the spacecraft's construction, SOHO is a
masterpiece of
international collaboration.
Weighing 1.85 tonnes at launch, the European-built SOHO was
dispatched by a
NASA rocket on 2 December 1995, and transferred to the vicinity
of Lagrange
Point No. 1, where it now hovers, 1.5 million kilometres from the
Earth.
The spacecraft was commissioned in April 1996 for a nominal
operational life
of two years, but this was later extended by five years until the
end of
March 2003.
Observations were severely interrupted twice, between 25 June and
5 November
1998, and between 21 December 1998 and 2 February 1999. The first
event was
due to loss of contact and control, and the second to gyroscope
failure. In
both cases ESA and NASA engineers, fully supported by SOHO's
constructor
Matra Marconi, worked wonders to restore the spacecraft to full
operations.
More than 30 eruptions called solar proton events have bombarded
SOHO with
energetic particles. The most severe, on 14 July and 9 November
2000,
temporarily blinded SOHO's instruments with particle 'snow' and
slightly
impaired the efficiency of the spacecraft's power-generating
solar panels.
More than 3600 coronal mass ejections from the Sun have been
observed by
SOHO's LASCO instrument, making an average of two per day during
SOHO's 5
years of observations.
SOHO is by far the most prolific discoverer of new comets in the
entire
history of astronomy. By mid-April 2001 the number stood at 304,
most of
them being small comets that fall into the Sun. Amateur
astronomers around
the world examine SOHO's daily pictures, via the Internet, and
have been
first to spot more than 200 of the SOHO comets.
The scientific payoff from SOHO is apparent in more than 2000
papers, theses
and reports, to which more than 1400 individual researchers have
contributed.
For more information please contact:
ESA - Communication Department
Media Relations Office
Tel: +33(0)1.53.69.7155
Fax: +33(0)1.53.69.7690
Dr. Bernhard Fleck, ESA - SOHO Project Scientist
ESA Space Science Dept, c/o NASA- GSFC, Greenbelt (Maryland,USA)
Tel: +1 301 286 4098
Fax: +1 301 286 0264
Email: bfleck@esa.nascom.nasa.gov
Dr. Paal Brekke, ESA - SOHO Deputy Project Scientist
ESA Space Science Dept, c/o NASA- GSFC, Greenbelt (Maryland,USA)
Tel: +1 301 286 6983
Fax: +1 301 286 0264
Email: pbrekke@esa.nascom.nasa.gov
============================
* LETTERS TO THE MODERATOR *
============================
(10) MORE ON THE P/Tr CONTROVERSY
From Hermann Burchard <burchar@mail.math.okstate.edu>
Dear Benny,
apropos Professor Andrew Glikson remark on CCNet April 24
referring to the
"P/Tr controversy", I wanted to mention that he has
been extremely helpful
in answering my e-mail questions and sending me his papers
concerning this
matter, the issue being whether a cometary or other cosmic impact
is
responsible for this major break in the geological record. As
stated in
several recent articles and letters posted by you on CCNet, the
P/Tr
boundary strata are strange and different to geologists from,
e.g., the K/T
boundary strata because of the absence in the P/Tr gap of
standard types of geological deposits associated with impact
craters and
their ejecta. As Andrew Glikson rightly emphasizes, large and
ancient
craters are still perfectly recognizable as cosmic impact sites
by such
ejecta and by typical features such as crushed rocks
characterised by shock
metamorphism, etc, near, in, and under craters.
So, what is the reason for the absence of, what are the
difficulties in
locating such impact indicators if indeed there was an impact in
the West
Sibirian Plane including the South Kara Sea (WSP)? According to
an article
which Dallas Abbott kindly sent me [with Nikishin, Ziegler et al,
from which several facts below are drawn], there is more basalt
in the WSP,
> 1.2 M km^3 (if the Taymyr is included), than in the entire
Sibirian Basalt
Plateau (SBP), = .7 M km^3. The SBP begins just east of Norilsk
with the
Putorana mountains, and tapers off toward Magadan on the Sea of
Okhotsk.
Thus, the 1600 km feature of the WSP is a gigantic lava bed,
similar to
Lunar Maria, in fact a terrestrial mare, where several fault/rift
basins
seem to indicate multiple impacts of cometary fragments. The
notion of
terrestrial maria was put forth by Alt, Sears, and Hyndman of
the University of Montana (1988). Are there some features other
than a vast
lava lake to indicate impact? (More data on how basalts within
the WSP are
distributed spatially would help here).
It is most peculiar that the city of Perm, situated on the west
side of the
Urals, gave rise to the name "Permian." The entire
western slope is Permian
or older sedimentary rock, there are no volcanics here. The
eastern slope of
the Urals, totally different from the western, is mainly
basalt dykes injected into sedimentary strata. Eclogites, ultra
high
pressure minerals making up an entire facies in the Northern
Urals, with
water, CO2 and nitrogen inclusions, are typically formed at about
10 km
depth when and where a slab of oceanic crust loaded with water is
subducted.
How did the eclogite facies get from a depth of 10 km to where it
is now, at
altitude? Why the East-West asymmetry?
This geological make-up of the Ural mountain chain, eclogites not
at depth
but raised high, and especially the remarkable asymmetry:
Western slopes = Permian sedimentary rocks, no
basalts,
Eastern slopes = basalt sheets/dykes
interbedded in sediments,
is exactly as expected for a deep asthenonsphere/mantle boundary
explosion
of one or more cometary pieces >80 km on the east side of the
mountains,
which is precisely where we find a giant terrestrial mare, the
WSP. The
impact may have occurred at or near oceanic crust, as the
eclogites, lifted from 10 km below sea-level to mountain heights
by the
impact, indicate a continental margin (the existence of which had
been long
established by geology), which is important because the
asthenosphere in
such spots is at moderate depth of perhaps only 50 or 70 km, to
where a 30km
comet fragment could penetrate.
The curved outline of the Urals is fine, but not important in
this argument
(a maths word -- what do geologists say?). It draws attention to
the area,
and makes it appear more like a mare on the map. Is Novaya
Semelya from the
same period, or later? It could be the wall for the South Kara
Sea impact
feature -- I hesitate to write "crater", as this is not
like continental
impact structures we have come to know and understand.
So, here are some of the missing pieces with impact in basalt of
subducting
oceanic crust, there would be no shocked quartz grains, and other
deposits
expected by the classical continental cratering studies [Dietz,
Shoemaker,
Glikson]. Sometimes drilling into craters exhibits impact
breccia. This may
not be possible in the WSP, where drilling to 7 km found no
basement
underneath the basalts (a similar situation seems to exist at
Chicxulub,
where according to a recent news item in the Dallas Morning Post
a pluton
has risen tens of km, from Michael Paine's web pages
-- however impact breccia has been found above the pluton, here
there was no
magmatic outpouring, and no mare was formed).
There are several fault/rift basins in the WSP. This suggests a
possible
multiple impact. The putative comet, an unstable pile of ice and
rock, is
expected to fragment at a mere tug of gravity in Earth's
vicinity.
Another impact apparently has hit in Southern China in the
Emeishan FBP,
where I continue to hold that flood basalts are unlikely to be
caused by a
doubtful instability deep in the core/mantle boundary. The FBP
there is
islolated from, yet roughly simultaneous with, the Sibirian
traps. This may
have been the same comet and the same day, as the comet
approaching Earth
began to break up over the Permian Pacific, about a few minutes
or more
likely a few hours earlier than the Sibirian impacts, depending
on the exact
manner of fracture of the comet.
One or more even earlier impact(s) west of China in the Permian
Pacific seem
very likely if the above facts are true. One might say, ocean
impacts are
implied by, or at least could explain, the peculiar nature or
strange
absence of ejecta, which up until now, according to the standard
geological
tests, did seem to throw grave suspicion on any impact theories,
as follows:
The water plume from a Pacific impact East of China ejected into
suborbital
trajectories would have come back down at about the same time as
the
Emeishan and Sibirian impacts. This could result in explosions
from those
later impacts being doused and ejecta washed away by water
pouring down from
the earlier impact(s). Furthermore, the geometry indicates a path
of the
cometary fragments that nearly grazed the eastern hemisphere,
coming in at a
shallow angle in the Western Pacific and lower still toward
arctic regions
(present-day crustal coordinates!), as additional fragments may
have
overshot the Earth near the (present-day) North Pole.
This low angle of attack explains a forward crater wall (Ural
mountains)
being thrown up, as the comet (fragment) buried under the crust,
not
exploding until deep under relatively undisturbed crust (up until
that very
moment), probably penetrating the asthenosphere.
Many other predictions can be made from an impact hypothesis
along these
lines for tests by geological evidence that is yet to be found.
The antipode
of the mantle spot where the main impactor hit (Hawaii) is at the
Columbia
Seamount, Ilhas Oceanicas da Trindade y Arquipelago Martin Vaz
off the East
coast of Brazil, for all of those antipode fanciers.
The size crater that the West Sibirian Basin might be (but
apparently there
are several "holes" dug by fragments) would require an
80 km to 100 km comet
minimum, perhaps several pieces >25 km. According to
Duncan Steel there are
dozens (hundreds ?) of comets >100 km in unstable orbits just
beyond Neptune
and further on in the Kuiper belt, waiting to be injected into
the inner
solar system upon passage near other bodies such as Neptune or
Pluto.
The hotspot formed by impacts in Western Sibiria, left a plume
that moved
East pouring out basalts first in the massive Sibirian traps of
the
Putorana, then tapering off in Far East Sibiria, then on to
Hawaii along the
Emperor-Hawaii Seamount chain. Or rather the crust moved West
over the
mantle, and the mantle spot under Hawaii is where the comet hit.
Thus the Eastern end of the SBP is in spatial proximity with the
Emperor
Seamount Chain, or its NW terminus, the Meiji Seamount. Drilling
by the DSDP
there found no useful basalts, a huge sedimentary apron covers it
deeply.
Still it can be shown to be about 85 Ma, from DSDP cores drilled
out of the
top of the 2nd oldest mount, the Detroit Seamount, which gave 81
Ma.
Many of the above facts are from explanations which Andrew
Glikson sent me,
and I hope that this exposition now makes better sense to him
than earlier
versions which he so very generously corrected.
Best regards,
Hermann Burchard
===========
(11) THE JORDANIAN FIREBALL EVENT
From Andrei Ol'khovatov <olkhovatov@mtu-net.ru>
Dear All,
In yesterday's CCNet (26 April 2001), a recent fireball event in
Jordan was
described. All data I have read so far about the event suggests
that it was
a geophysical event similar to the Dec.4, 2000 Salisbury event,
which was
discussed on CCNet in December 2000. There is still no official
name for
such a type of event, but I prefer to call them (including
reports for
several conferences) as "geophysical meteors", or
"geometeors". The
existence of some probably non-meteoroidal meteor-like phenomena
was
suspected for a long time (see W. Corliss' books on geophysical
anomalies,
for example), but little attention was paid to them, and they
were
practically forgotten or ignored.
A physical mechanism of them is not known, but probably it is
associated
with some electromagnetic phenomena. Anyway, a geophysical meteor
often
resembles a very large and energetic high-speed ball-lightning.
There are
some relationships of a geophysical meteor with geological and
meteorological
factors. We just begin to investigate this mysterious and
exciting phenomenon,
and apparently many new interesting discoveries are waiting for
us. For
example, it is very important to investigate the samples taken in
the Jordan
event impact site. Maybe some CCNet readers could help with this?
You can read more on geophysical meteors in:
www.geocities.com/olkhov/gr1997.htm
Sincerely,
Andrei Ol'khovatov
Russia, Moscow
==========
(12) FINAL AUSTRALIAN SCIENCE TV PROGRAMME LEADS WITH IMPACT
THREAT
From Michael Paine <mpaine@tpgi.com.au>
Dear Benny
Last night saw the final episode of the long-running and
informative science
program Quantum on Australian television. In January the
government
(under) funded Australian ABC disbanded its Science Unit and now
we have seen
the demise of Quantum. So much for the delusion that Australia is
a "clever
country"! There is a rally at the Sydney Opera House on
Sunday to protest
the ABC funding cuts. Anyway, the episode highlighted science
developments
over the twenty or so years of Quantum broadcasts. To my surprise
and
delight the program led with the threat to Earth from asteroids
and comets.
It featured interviews with Don Yeomans and Gene Shoemaker.
regards
Michael Paine
=========
(13) REINVENTING PLATE TECTONICS
From Konrad Ebisch <kebisch@zycor.lgc.com>
Re: A "FOUR-PISTON ENGINE" DRIVES EARTH FROM INSIDE,
NEW STUDY SHOWS (CCNet
26/4/01)
By Carmen Kinniburgh and Janet Wong
"The plate tectonics theory, proposed in the 1960s, suggests
Earth's
crust is split up into a few immense plates that constantly shift
and
produce earthquakes, but it does not explain how this movement is
linked
to processes occurring deep inside the planet, says Forte."
1960's? Try Alfred Wegener, 1915, The Origin of Continents and
Oceans or
even Abraham Ortelius 1596.
Konrad Ebisch
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*
CCNet CLIMATE SCARES & CLIMATE CHANGE, 27 April 2001
----------------------------------------------------
"The acid test of all this is the last 22 years of satellite
measurements made of the lower layer of air of the Earth. That
layer of air
should be warming quite rapidly. It's where the carbon dioxide
greenhouse effect should be taking place. That layer there has
not seen
a big warming trend. It's seen ups and downs but there's been no
net trend.
That layer of air has to warm first according to the models. Then
it, in
turn, warms the surface. Now we've seen a little bit of warming
of the
surface, but it can't be caused by that carbon dioxide effect in
that
atmospheric layer, which has no warming. You can't bypass the
lower
layer of air and warm the surface by carbon dioxide effect. So
the satellite
measurements, which are precise and validated by independent
balloons
everyday, say that there has been no effect that we can see and,
therefore, the future effect is going to be minimal.
--Sallie Baliunas, Harvard Smithsonian Center for
Astrophysics, 26 April 2001
"Chapter 11 on "Sea Level Changes" of IPCC's 1999
TAR paper was
written by 33 persons; none of whom represents actual sea level
research. I have now finished a 7 pages review report. It is a
most
shocking reading; lots of modeler wishes but very little hard
facts based on
real observational data by true sea level specialists. I allow
myself a few
quotations.
"It seems that the authors involved in this chapter were
chosen not
because of their deep knowledge in the subject, but rather
because they
should say what the climate model had predicted. This chapter has
a low
and unacceptable standard. It should be completely rewritten by a
totally new group of authors chosen among the group of true sea
level
specialists".
--Nils-Axel Mörner, President of the INQUA Commission on
"Sea Level Changes and Coastal Evolution"
(1) RECORDS 'SHOW STRONG RECENT WARMING' (WHICH BEGS THE
QUESTION: WHY IS IT
SO DAMN COLD?)
BBC News Online, 26 April 2001
(2) MOST SERIOUS GREENHOUSE GAS IS INCREASING
Andrew Yee <ayee@nova.astro.utoronto.ca>
(3) HERE COMES THE SUN TO FURTHER CLOUD GLOBAL WARMING THEORY
TechoCentralStation, 23 April 2001
(4) HOW CLIMATE CHANGE KILLS SOCIETIES
MSNBC, 26 April 2001
(5) CULTURAL RESPONSES TO CLIMATE CHANGE DURING THE LATE HOLOCENE
Science Online, 27 April 2001
(6) TIME'S WARMING RETREAT
New York Post, 24 April 2001
(7) NO NOAH'S FLOOD
Nils-Axel Mörner <Nils-Axel.Morner@pog.su.se>
(8) NOAA'S FLOOD
Jonathan Shanklin <jdsh@bas.ac.uk>
(9) CORAL ISLAND, SEA LEVELS & ASTEROID IMPACTS
Duncan Steel <D.I.Steel@salford.ac.uk]
(10) CLIMATE RESEARCH AND CONSPIRACY THEORIES
Andrew Glikson <geospec@webone.com.au>
(10) CLIMATE RESEARCH AND CONSPIRACY THEORIES II
Max Wallis <wallismk@Cardiff.ac.uk>
(11) AND FINALLY: IGNORE GLOOMY INTELLECTUALS AND LOOK AT THE
FACTS
Reason Online, 25 April 2001
=========
(1) RECORDS 'SHOW STRONG RECENT WARMING' (WHICH BEGS THE
QUESTION: WHY IS IT
SO DAMN COLD?)
From the BBC News Online, 26 April 2001
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1298000/1298562.stm
Scientists have analysed climate data for the 20th century
By BBC News Online's environment correspondent Alex Kirby
UK scientists say a thousand years' climate records show the last
three
decades were the millennium's warmest.
They also conclude that natural phenomena like El Nino are
unlikely to have
caused the unprecedented recent warming.
Their findings strengthen the argument that climate change is not
produced
by natural causes alone.
The scientists are Professor Phil Jones, Dr Tim Osborn, and Dr
Keith Briffa,
all from the Climatic Research Unit at the University of East
Anglia. They
report their work in the journal Science.
Their analysis included instrumental and documentary records, and
also other
"proxies" of past climate variability - evidence from
tree rings, corals and
ice cores.
Warmest century
For the northern hemisphere, their temperature reconstructions
show that
"the recent 30-year period is likely to have been the
warmest (about 0.2
degrees Celsius above the 1961 to 1990 average) of the
millennium, with the
warmest century (by about 0.1 degrees C) likely to have been the
20th".
Greece has been hit by forest fires in recent years
The authors say the first half of the millennium was milder than
the 1500 to
1900 period. The coolest century was the 17th., followed by the
19th., with
a milder interval between.
They add that their work provides some support for the idea that
there were
two epochs in the last millennium, the medieval warm period,
spanning
roughly 900 to 1200, and the little ice age from about 1550 to
1900.
The authors say: "The southern hemisphere temperature
reconstructions are
shorter and less reliable; they do indicate cooler conditions
before 1900,
but not the same inter-centennial variation evident in the north.
"The average shows greater recent warming than earlier in
the 20th century,
and there is no evidence of the slight 1945 to 1975 cooling seen
over many
northern hemisphere land areas.
"Instrumental data from Antarctica show a temperature rise
until the early
1970s, with little change since then."
Greatest warming
Professor Jones said: "The accuracy of records for the first
half of the
millennium is sometimes queried. We have calculated errors, and
the picture
is clearer. All records show that the 20th century experienced
the greatest
warming of the millennium.
"Examining this broad span of records from all parts of the
world, we see
that the North Atlantic Oscillation, which is responsible for the
UK's
recent milder, wetter winters, has behaved in this unusual way
before,
notably in the 1730s, the mid-19th century, and the early 1900s.
"Similarly, we find elevated activity of El Nino events in
some earlier
periods. Some people have attributed global warming to these two
phenomena.
But the records show that their past activity did not result in
significant
warming."
No freeze
The scientists say it is important to recognise the dangers of
taking
documentary sources at face value.
They say accounts of the Thames freezing over in the past are
often cited as
proof that winters were colder then. But they say a significant
factor in
the freezing of the river was the way the old London Bridge was
built with a
number of piers, encouraging a process known as
"ponding". In the winter of
1962/63, the third coldest since 1659, the river did not freeze
at all.
There has been no complete freezing since the bridge was rebuilt
to a
different pattern between 1825 and 1835.
Professor Jones told BBC News Online: "Our work is part of
the jigsaw,
narrowing down the range of possible past climates. It shows that
it is more
likely that the underlying trend in global warming is the result
of human
influence."
Copyright 2001, BBC
============
(2) MOST SERIOUS GREENHOUSE GAS IS INCREASING
From Andrew Yee <ayee@nova.astro.utoronto.ca>
University of Washington
Seattle, Washington
FROM: Vince Stricherz, 206-543-2580, vinces@u.washington.edu
FOR IMMEDIATE RELEASE: April 24, 2001
Most-serious greenhouse gas is increasing, international study
finds
Scientists know that atmospheric concentrations of greenhouse
gases such as
carbon dioxide have risen sharply in recent years, but a study
released
today in Paris reports a surprising and dramatic increase in the
most
important greenhouse gas -- water vapor -- during the last
half-century.
The buildup of other greenhouse gases (those usually linked with
climate
change) is directly attributable to human activity, and the study
indicates
the water vapor increase also can be traced in part to human
influences,
such as the buildup of atmospheric methane. However, other causes
not
directly related to humans must also be at work, said Philip
Mote, a
University of Washington research scientist who is one of seven
lead authors
on the report.
"Half the increase in the stratosphere can be traced to
human-induced
increases in methane, which turns into water vapor at high
altitudes, but
the other half is a mystery," said Mote. "Part of the
increase must have
occurred as a result of changes in the tropical tropopause, a
region about
10 miles above the equator, that acts as a valve that allows air
into the
stratosphere."
Readings of water vapor increases 3 to 10 miles up are more
ambiguous, Mote
said. The international study, produced by 68 scientists in seven
countries
as part of the World Climate Research Programme, examined only
the changes
at higher altitudes, 3 to 30 miles above sea level.
Although carbon dioxide has been relatively easy to monitor and
increases
have been observed since the 1950s, water vapor has proven much
more
difficult to monitor. The new effort for the first time was able
to draw
conclusions about the behavior of water vapor based on a large
number of
measurements during a long period of time. The report covered
both the upper
troposphere (3 to 10 miles high), where trends are harder to
detect, and the
stratosphere (10 to 30 miles high).
"A wetter and colder stratosphere means more polar
stratospheric clouds,
which contribute to the seasonal appearance of the ozone
hole," said James
Holton, UW atmospheric sciences chairman and expert on
stratospheric water
vapor. "These trends, if they continue, would extend the
period when we have
to be concerned about rapid ozone depletion."
Atmospheric heating happens when the Earth's atmosphere and
surface absorb
solar radiation, while cooling occurs when thermal infrared
radiation
escapes the atmosphere and goes into space. If certain key gases
that absorb
and emit infrared radiation, the most important being water vapor
and carbon
dioxide, were not present in the atmosphere, Earth's temperature
would cool
to minus 19 degrees celsius, or minus 2 degrees Fahrenheit. The
global
annual mean temperature is 14 degrees celsius.
Key findings of the water vapor assessment are:
* Ground-based, balloon, aircraft and satellite measurements show
a global
stratospheric water vapor increase of as much as 2 parts per
million by
volume in the last 45 years, a 75 percent jump.
* Modelling studies by the University of Reading in England show
that since
1980 the stratospheric water vapor increase has produced a
surface
temperature rise about half of that attributable to increased
carbon dioxide
alone.
* Methane, which has been increasing in the atmosphere since the
1950s,
could be contributing to the water vapor increase. Chemical
conversion of
methane to water vapor occurs in the stratosphere but can only
account for
at most half of the water vapor increase.
A satellite record of relative humidity data for the upper
troposphere shows
a 2 percent increase during the last 20 years in the equatorial
region.
However, the uncertainty in this determination is too large to
allow a clear
conclusion as to whether this is part of a long-term trend.
Among other things, the report recommends continuing to launch
balloons
monthly from Boulder, Colo., as a means to measure water vapor, a
low-cost
effort that nevertheless faces possible discontinuation. The
balloon
measurements, dating from 1981, are the only continuous record of
water
vapor.
Holton said the report is significant because, by careful
comparison, it
largely has resolved contradictions in measurements among a
number of
instruments.
###
For more information, contact Mote at (206) 616-5346 or
philip@atmos.washington.edu,
or Holton at (206) 543-401
=======
(3) HERE COMES THE SUN TO FURTHER CLOUD GLOBAL WARMING THEORY
From TechoCentralStation, 23 April 2001
http://www.techcentralstation.com/bigshotfriday.asp
Debate on the causes of predicted global warming usually revolves
around
climate models scientists construct. But can those models account
for all
the variables the universe has to offer? Not really, according to
Dr. Sallie
Baliunas of the Harvard Smithsonian Center for Astrophysics, who
puts forth
the sun as a variable not to forget.
"The science altogether is unsettled, but we know for sure
that the models
that make the predictions into the future are exaggerating the
warmth," Dr.
Sallie Baliunas tells TechCentralStation Host James Glassman.
Baliunas points out that increases in magnetism at the center of
our solar
system correlate quite strongly with temperature rises here on
Earth. She
also notes the difficulty of this scientific enterprise saying,
"There are
something like 5 million parameters that have to go into a good
climate
model, and it has to compute for a time longer than the age of
the universe
if we wanted to know something."
She and Glassman recently talked in Boston about the science, the
uncertainty, and the sun's perhaps overlooked influence on
climate change.
James K. Glassman: Dr. Baliunas, we've heard that temperatures
have
increased on Earth over the last century. Now, is our assumption
essentially
that they had been stable before that?
Sallie Baliunas: The temperature of the Earth has increased over
the last
100 years. We have instruments - thermometers -- at the center of
the Earth
that tell us that. The warming began early in the 20th century,
late in the
19th century. But before that, there was a very long, protracted
cooling
that began in the 14th century that continued to the mid 19th
century -- a
500-year relative cold spell called the ice age. Before that, 800
or 1,000
years ago -- the early part of the millennium -- the temperature
was even
higher than today, worldwide.
Glassman: So you're saying there was global warming before the
20th and 21st
centuries?
Baliunas: Yes.
Glassman: Well, they didn't have SUVs then?
Baliunas: No.
Glassman: Why was the Earth heating up?
Baliunas: Well, the one property of climate is change. The
temperature of
the Earth has changed dramatically in some cases. And it's
changed
relatively greatly in the last 1,000 years even.
Glassman: How can you tell?
Baliunas: The thermometers go back only about 100 years or so
over some
substantial portion of the Earth. Then we have to rely on other
records,
things that help us reconstruct the climate. For example, growth
of tree
rings is retarded during cold times usually and then is more
advanced during
warm times. So by boring into tree rings scientists can tell
where there are
milder periods or cooler periods. And then there are many
indicators.
Glaciers advance and retreat, mountain glaciers, polar glaciers.
Coral
growth rings tell us about the temperature of the ocean. There
are many such
indicators that go back 100 years.
Glassman: So if there was global warming way back, way before the
20th
century, and it wasn't the result of spewing gasses into the air,
that is to
say man-made global warming, then what caused it?
Baliunas: That's the big question. We need to answer the
question: What are
all the causes of climate change, natural climate change, that is
non
man-made? Look back in time, before the time when most of the
carbon dioxide
had been put in the air, you still see natural changes of a
degree or so
over decades or centuries, which is on the order of what the 20th
century's
warming has been.
Now to answer your question, we've been looking at changes in the
sun's
energy output and we can measure changes in the sun's energy
output going
back 10,000 years by looking at tree rings, interestingly enough.
And when
we do that, we see the ups and downs of the climate of the last
1,000 years
and even of the 20th Century match very well with the changes of
temperature.
Glassman: In other words, what you're saying is that because of
activity on
the surface of the sun, the Earth is warming up?
Baliunas: Right. When the sun's magnetism is strong, the sun's
energy output
is higher and the Earth is warmer. We see that as a fact. We
measured that
carefully over the last 20 years with satellites from the Earth,
and we
measured it indirectly going back 400 years, 1,000 years, and
10,000 years.
Glassman: So in effect there are times when the sun is warmer
than at other
times?
Baliunas: Yes, and that warmth means the climate of the Earth
warms up.
Glassman: Now, have you actually correlated the activity of the
sun with
this magnetism that you're talking about, with the rise of
temperatures on
Earth?
Baliunas: Yes, the correlation is very strong. For the
temperature records
going back on Earth, we can reconstruct the northern hemisphere
about 250
years or so. And the ups and downs of temperature match almost
exactly the
up and downs and change in magnetism, and so, the energy output
of the sun.
As the sun is warming and cooling, the Earth's temperature is
responding.
And it doesn't take much of a change of the sun either -- only
about a few
tenths of a percent of its energy output to cause these
temperature swings.
Glassman: So, for example in the 1300s was there a period of
global warming,
climate change with temperatures rising? Was there solar activity
then?
Baliunas: With records going back 1,000 years of solar magnetism,
and the
warm period certainly was in effect from about the years 1000 to
1200, maybe
1300 was about the edge of it, then there started to be a
cooling. That 200-
or 300-year period, the sun was much more active, magnetically,
and we
think, therefore, much brighter energetically than it is today.
And then the
magnetism declined into a long period of very low magnetism,
lower energy
output, and in step with these major changes in the Earth's
climate over the
last thousand years.
Glassman: Has there been solar activity over the last hundred
years that
would correlate with the temperature on Earth?
Baliunas: Yes, it correlates almost exactly with the temperature
on Earth.
The sun is as magnetically active as it's been in our direct
telescope
records of the sun since the days of Galileo. So the magnetism of
the sun
has been rising gradually, and it was especially sharp early in
the 20th
century, coincident with this rise in temperature on the Earth.
Glassman: Now there were declining temperatures from the 1940s
through the
mid-70s. Was there a lack of magnetism?
Baliunas: Yes, from about the 1930s, the 1940s the sun's
magnetism waned a
little bit and has since picked up a little bit.
Glassman: What you're saying is that solar activity is causing
global
warming?
Baliunas: We are looking to find all the causes of natural change
of the
climate of the Earth, the sun being one of them. That way we can
subtract
out the natural changes and look for the human signal. We see,
essentially,
no signal of human activity.
Most of the changes that we see line up with the changes in the
sun. Now
there's some uncertainty, so there may be a human signal. But if
there is,
it's quite tiny.
Glassman: What do your colleagues think of this idea?
Baliunas: It's very interesting. Many of the climate models now
try to
incorporate the effect of the sun on them. Our next stumbling
block is what
exactly is the mechanism for change on the sun, and how does the
Earth
respond to that?
We think first of changes in the total energy output of the sun,
but that's
not the only way the sun changes. Different wavelengths of light
are
changing, and there are also high energy particles coming out of
the sun,
changing in step with these changes. Some scientists have thought
that those
particles, for example, produce changes in cloud cover on Earth
and change
the temperature. We have to understand that before we can make a
good
estimate of what the sun's impact is. Right now everyone is
struggling with
the causes.
Glassman: Your colleagues, fellow astrophysicists, don't say,
"Oh, this is
some sort of silly idea"?
Baliunas: No, astronomers know the sun is a variable star.
Glassman: But, apparently, a lot of journalists or a lot of
people who
politicize this issue don't understand that?
Baliunas: They don't understand it, yeah. But it'll take time for
their
education.
Glassman: Let me ask you about ice at the North Pole. According
to the
global warming theory, it should be melting rapidly. But you say
that ice
isn't cooperating with that theory?
Baliunas: No, neither ice nor temperature is cooperating with the
model of
predictions. You're so right that the models, the computer
output, says that
the North Pole should be warming dramatically and rapidly. It
hasn't been.
It's really been cooling. Ice packs have been growing. There's
just been no
evidence that the Poles have been warmer. And to go look at, say,
cracks in
the ice or the caving of an iceberg and then to work backwards
from that and
say that has a human cause, that's just bad logic.
Glassman: I have read articles in the New York Times and
elsewhere about the
observation of some icebreakers saying, "Wow, there's
doesn't seem to be as
much ice up here." You're saying that that's not a very good
way to look at
it.
Baliunas: No, those observations have been overturned. There's
just been a
paper published about sea ice thickness in the North Pole and
temperatures.
If the issue is temperature, looking at the ice is a proxy for
temperature.
Ice can change for reasons other than temperature. It can change
because
precipitation's changed. Some of the models, in fact, say that
sea ice
should be growing as you warm a little bit because it's so cold
at the North
Pole that you warm a little bit and get more precipitation.
Glassman: As a scientist, how do you react to journalistic
coverage of this
issue?
Baliunas: I try to read it all because people want to know the
answer. But
there's a sociology to journalism that I don't subscribe to, and
so I'm not
a journalist. That sociology is that scary stuff sells
newspapers.
Glassman: And you're a scientist, so you want to find out what's
really
going on?
Baliunas: Scientists have to go by the facts.
Glassman: How much warming have we actually seen in the last 100
years?
Baliunas: There's been about a half a degree centigrade or a
degree
Fahrenheit warmer. Most of that warming occurred early in the
century,
before the greenhouse gasses by human activities were added to
the
atmosphere.
Glassman: And is this the first time we've ever seen warming on
this planet?
Baliunas: Oh no. (laughs) No. There have been times -- the
warming in the
late 19th century, especially in the high polar regions -- that
can't be
caused by the human-induced gasses. That was much stronger than
any warming
we've seen in recent decades. Now with ice core records --
fellows who drill
in the high latitudes and polar regions and pull up a hundred
thousand, two
hundred thousand years of ice core layers that tell you the
temperature -
there's some warmings and coolings there over decades that are
astonishing:
several degrees. Not man-made.
Glassman: And when you say every decade, you're talking about
thousands of
years ago or hundreds of years ago?
Baliunas: Well, some of these episodes during the little ice age,
for
example, were just several hundred years ago.
Glassman: If there is an increase in temperature, and as you say
it has been
a half a degree over the past century, people are worried that
maybe that is
the beginning of a big acceleration of temperature. Do you think
the science
is settled at this point about whether we'll have any more global
warming?
Baliunas: I think the science is settled that the predictions are
exaggerated. There is maybe some human-made warming, but it's
going to be so
small that it's going to be lost in the natural variability. And
that's the
conclusion from science.
The acid test of all this is the last 22 years of satellite
measurements
made of the lower layer of air of the Earth. That layer of air
should be
warming quite rapidly. It's where the carbon dioxide greenhouse
effect
should be taking place. That layer there has not seen a big
warming trend.
It's seen ups and downs but there's been no net trend. That layer
of air has
to warm first according to the models. Then it, in turn, warms
the surface.
Now we've seen a little bit of warming of the surface, but it
can't be
caused by that carbon dioxide effect in that atmospheric layer,
which has no
warming. You can't bypass the lower layer of air and warm the
surface by
carbon dioxide effect. So the satellite measurements, which are
precise and
validated by independent balloons everyday, say that there has
been no
effect that we can see and, therefore, the future effect is going
to be
minimal.
Glassman: As far as the causes of this one-half degree increase
are
concerned, do scientists in your field, really the climate
scientists, have
a settled conclusion as to why that's occurred?
Baliunas: No. I think right now everyone's looking at the sun as
one reason,
but there are issues of the ocean, ocean circulation, ocean
changes on time
scales of decades to centuries. And we don't understand that. We
don't
understand the mechanism for the sun. There's still many
surprises left.
Glassman: Would you say, in general, that at this point the
science is
unsettled?
Baliunas: The science altogether is unsettled, but we know for
sure that the
models that make the predictions into the future are exaggerating
the
warmth.
Glassman: If we could somehow find a way to reduce CO2 in the
atmosphere
without slowing our economy, which is a big if, are we certain
that that
would actually help us in terms of reducing global warming?
Baliunas: That's an interesting question. There certainly is a
technology
that is easy and affordable, it's just not politically palatable.
And that
is nuclear power. Nuclear power produces no carbon dioxide. We
know how to
build nuclear power plants, it just seems to me culturally and
politically
unforeseeable in the future. So, that would do it without
wrecking the
economy while still having growth in energy use.
The other question is much more important. If you put all these
resources
into mitigating a problem, what other problems are you taking
those
resources from? Since we can't see a human-made carbon dioxide
signal where
there should be one, it means that the carbon dioxide effect from
human
activities must be quite small.
Glassman: Let's say everyone stopped emitting any greenhouse gas.
All human
greenhouse gasses were just halted. Do you think that it's still
possible to
have global warming?
Baliunas: Yes. If the causes of global warming are not owing to
human
activities, then the climate will continue on its course of
change. It may
be solar, it may be related to the oceans, it may be internal to
the Earth's
climate. So the fact that we stop emitting carbon dioxide will do
nothing to
change the course of the climate. There's one interesting related
issue,
which is carbon dioxide in the air in recent decades has produced
a
tremendous agricultural boom. There have been estimates of at
least a 10
percent efficiency increase. So plants have been growing quicker,
better,
greener. Crops have been growing better. This has been for free,
essentially. So cutting carbon dioxide means we lose that
increase in
efficiency that we've gained.
Glassman: But back in 1100, 1200 we saw a rise in the temperature
of the
Earth, even though, I guess we can assume there weren't a lot of
greenhouse
gasses being emitted by people in the Middle Ages.
Baliunas: That's right, absolutely. In the 10th, 11th century, it
looks to
me like the sun's energy output rose and that's really what
caused the
warming back then. If you're a student of history, you'll know
that was a
great time of expansion in Europe: town building, city building,
university
building, church building, trade, because the climate was really
benign.
Glassman: How long do you think it will be until we'll actually
be able to
say, in a conclusive way, what has caused the warming that's
occurred in the
last century?
Baliunas: That's a very hard question and I really, I really
don't know.
Every few years everyone says that another 10 years of research
and we'll
know. But we've been saying that for 10 or 20 years now.
Glassman: Has anyone brought forth any evidence that says,
"Dr. Baliunas
says there's a correlation between magnetic activity of the sun
and the rise
of temperature on Earth, but this, that and the other disproves
that"?
Baliunas: I don't see how you can't disprove the correlation. The
next step
is for us to find the mechanism for that correlation. The
correlation is
only the starting point. It may be that it's a coincidence that
these two
things have changed together.
Glassman: But that would be quite a coincidence?
Baliunas: It seems odd because we have some mechanisms that look
like they
might explain it. We now have to prove that.
Glassman: I've read a lot about how humans are going to be
causing a
dramatic warming. A recent summary of a UN report forecast
possible floods
and extreme weather and outbreaks of malaria -- incredible
predictions.
Baliunas: They're not credible, as the scientific report states.
To get an
estimate of what climate is going to be by region is not possible
region by
region. And you can't look at those outcomes like floods and
storms. Models
have no ability to sees storm fronts, for example. So they can't
predict
that. It even brings up the point about how credible the average
temperatures are, globally -- those that are often quoted. Global
averages
are made out of region-by-region averages, which are admittedly
incorrect --
wrong in some cases by 11 degrees centigrade over portions of the
United
States. Rainfall is wrong by 200 percent in some areas. So
averaging out all
of those mistakes can't possibly give you anything reliable, even
in the
global average.
Glassman: We know how difficult it is to predict the weather for
tomorrow;
so, how are we going to predict the climate 100 years from now?
Baliunas: That's exactly the problem. Predicting the weather is
done on a
very small scale. We have to try to do that globally, but we
can't do that
because the computer power isn't available. We also don't have
the knowledge
of what changes in the climate. So we have to make some
assumptions and
guesses. There are something like 5 million parameters that have
to go into
a good climate model, and it has to compute for a time longer
than the age
of the universe if we wanted to know something. So we can't. We
have to make
simplified assumptions. We know those assumptions are wrong. We
know the
outcome doesn't match up with reality.
Glassman: Frequently we hear the press and politicians jump on an
issue that
relates to science and blow it all out of proportion. The recent
Y2K crisis
was a good example. But I think we've seen something else related
to
climate. About 25 years ago, weren't people talking about
something else
happening in the climate?
Baliunas: Yeah, well, weather and climate are important issues
for humans.
At about the 1940s, the temperature reached a maximum and then
began to
decline. And by the 1970s, it looked like it might be a crisis.
So there
were scientists saying that the ice age was coming, in part
aggravated by
soot and smokestack emissions that were also being looked at
around that
time.
Glassman: So these smokestack emissions were supposedly blocking
the sun? Is
that right?
Baliunas: Right. The smokestack emissions, the soot causes a
shading effect
of sunlight. So it was thought that they may be producing that
1970s
cooling. This probably isn't so. Nonetheless, there was a huge
cry that,
perhaps, the next major glaciation was occurring -- which really
would be
serious.
Glassman: Whatever happened to those people who were talking
about global
cooling?
Baliunas: Oh, they then looked at their models, added carbon
dioxide's
effect and then began to talk about global warming.
Glassman: So they went from global cooling to global warming in a
very short
period of time?
Baliunas: Many of them did, yes.
Glassman: Looking back at the global cooling scare, I guess it's
good we
didn't try to fix that one?
Baliunas: No, I don't know how you... we could not have fixed
that problem.
And I'm not sure we can fix the carbon dioxide problem, whose
evidence can't
be seen.
Glassman: Now, isn't it also true that some leaders of the global
warming
movement were also highly active with the global cooling
movement?
Baliunas: I guess for some people you just can't lose.
TechCentralStation © 2001
=======
(4) HOW CLIMATE CHANGE KILLS SOCIETIES
From MSNBC, 26 April 2001
http://www.msnbc.com/news/564306.asp
Researcher traces the historical effects of long-term
shifts
By Becky Ham
WASHINGTON, April 26 - Timing couldn't have been worse for
the group of
colonists who came ashore on Roanoke Island in 1587, attempting
to establish
the first permanent English settlement in the New World. Along
with the
usual hardships of starting a new society on the edge of the
wilderness, the
colonists were confronted with the region's worst drought in 700
years,
which caused mass starvation and aggravated tense relations with
Native
Americans. By 1590, the ill-fated settlers had vanished with
little trace.
Roanoke's collapse in the face of harsh climate puts it in
distinguished
company, a researcher reports in the journal
Science.
RECENT CONCERNS about global climate change, especially the
impact of human
activity on these changes, have sent scientists scrambling to
discover how
current climate trends fit into the larger picture of climate
change
throughout Earth's history. With a growing pile of paleoclimate
data at
their disposal, researchers are also taking a closer look at how
complex
societies responded to past climate change.
Understanding how these cultures adapted to events like
persistent droughts
could provide valuable perspective on how modern societies might
respond to
future climate change, says Peter deMenocal, a researcher at the
Lamont-Doherty Earth Observatory of Columbia University.
THE LONG VIEW
Modern climate data, recorded by instrument, allow us to study
climate
phenomena that vary on a time scale of several years, such as El
Niño,
deMenocal notes in Friday's issue of Science. But that record is
far too
short to capture large-scale events like the drought that wiped
out Roanoke
- events that we can confirm through other detailed climate
records like
tree rings or lake sediments.
These climate proxies, among others, indicate that the past
12,000 years of
Earth's climate have been a bumpy ride, punctuated by widespread
cooling
events and droughts that persisted for decades and often
centuries. These
events are associated with changes in ocean circulation, solar
radiation and
volcanism. Many of them occur on thousand-year cycles, indicating
that solar
variability and interactions between the ocean and atmosphere are
especially
important factors influencing these climate changes.
A growing store of detailed and well-dated paleoclimate records
has
contributed to "a transformation in the field that allows
scientists to
evaluate cultural records within the context of climate,"
deMenocal says.
Researchers are using this new perspective to examine how past
societies
managed to cope - or failed to cope - with prolonged and severe
climate
events, events without equal in modern times.
COLLAPSE AND ABANDONMENT
This new outlook suggests, for instance, that the Akkadian Empire
in
Mesopotamia may have been one of the earliest complex societies
felled by
severe drought. The Akkadian Empire was established around 2300
B.C.,
linking rain-fed agricultural fields in northern Mesopotamia with
irrigation
agriculture in the south. The empire stretched from the
present-day Persian
Gulf into Turkey before it abruptly collapsed less than 200 years
later.
By 2170 B.C., archaeological records document a mass exodus from
the north,
with settlements abandoned and refugees pouring into southern
Mesopotamia.
Excavations at one of these settlements, Tell Leilan, show that
the collapse
is marked by a thick layer of windblown dust without any
artifacts. Three
hundred years later, smaller and more nomadic groups finally
ventured north
again.
An excavated sample of residential occupation within the lower
town of Tell
Leilan in northeast Syria during the final days of the Akkadian
Empire.
Researchers found the same telltale signature of drought in a
deep-sea
sediment core drilled from the Gulf of Oman. The core documents a
dramatic
300-year period of windblown dust that could be dated to roughly
the same
period as the Akkadian collapse. Chemical traces in the dust
allowed the
scientists to pinpoint its origins in Mesopotamia.
The severe climate change that may have helped topple the
Akkadians probably
had its roots in the far-off North Atlantic Ocean. Atlantic
deep-sea cores
suggest that the start of the Mesopotamian drought coincides with
widespread
cooling in the northern part of the ocean, which could have
affected
rainfall that typically fed Mesopotamia's rivers. Modern records
show that
water supply for Mesopotamia can be cut in half when North
Atlantic sea
surface temperatures are unusually cool, deMenocal
notes.
Several thousand years later, on the other side of the world, the
Tiwanaku
culture in South America faced a similar climate challenge.
Between 300 B.C.
and A.D. 1100, the Tiwanaku built an urban complex that probably
supported
nearly half a million people. They sustained this dense
settlement through
raised field agriculture, a technique that improved drainage and
recycled
nutrients in the poor tropical soil.
The raised fields of the Tiwanaku may be a good example of a
complex society
already responding to the challenges of a marginal environment,
and
therefore vulnerable to sudden climate change, says deMenocal.
Around the
year 1100, the cities and fields were abruptly abandoned.
Once again, the paleoclimate record may contain clues to the
Tiwanaku
collapse.
The Quelccaya ice core, drilled just 125 miles from Lake
Titicaca, contains
an annual record of precipitation for the region. This ice core
record shows
close overlap between the time of the Tiwanaku abandonment and
the start of
an increasingly dry spell. Sediment cores from Lake Titicaca
itself also
chronicle the event, showing a 33-foot drop in the lake level at
the time.
The drought persisted for several centuries, during which the
Tiwanaku went
into a slow decline.
Solar input
The sun's energy, after traveling 93 million miles to get to
Earth, hits the
upper atmosphere at about the intensity of three 100-watt bulbs
per square
yard. A third is reflected back into space, two thirds warms the
planet and
drives its weather engine.
The atmosphere
Earth gets its livable temperature (on average 59 degrees
Fahrenheit) thanks
to a delicate balance of gases that create a
"greenhouse" effect by trapping
heat inside the atmosphere. Greenhouse gases -- water vapor,
carbon dioxide,
methane, nitrous oxide, and others -- absorb heat energy, then
re-radiate a
portion of it back to the surface.
The oceans
Covering two thirds of the planet, oceans are the key source of
moisture in
the air and they store heat efficiently, transporting it
thousands of miles.
The oceans and marine life also consume huge amounts of carbon
dioxide.
The water cycle
Higher air temperatures can increase water evaporation and
melting of ice.
And while water vapor is the most potent greenhouse gas, clouds
also affect
evaporation, creating a cooling effect.
Clouds
They both cool Earth by reflecting solar energy and warm Earth by
trapping
heat being radiated up from the surface.
Ice and snow
The whiteness of ice and snow reflects heat out, cooling the
planet. When
ice melts into the sea, that drives heat from the ocean. Northern
Hemisphere
snow cover has declined 10 percent in two decades, but no
significant
melting of the Antarctic ice sheet has been detected.
Land surface
Mountain ranges can block clouds, creating 'dry' shadows
downwind. Sloping
land allows more water runoff, leaving the land and air drier. A
tropical
forest will soak up carbon dioxide, but once cleared for cattle
ranching,
the same land becomes a source of methane, a greenhouse gas.
Human influences
Humans might be magnifying warming by adding to the greenhouse
gases
naturally present in the atmosphere. Fuel use is the chief cause
of rising
carbon dioxide levels. On the other hand, humans create
temporary, localized
cooling effects through the use of aerosols, such as smoke and
sulfates from
industry, which reflect sunlight away from Earth.
'WE HAVE TO RELEARN HISTORY'
The fate of the Akkadians and the Tiwanaku begs the question: If
a
centuries-long drought descended today, how would we respond?
One of the most destructive droughts in recent memory is the
1930s American
Dust Bowl, which lasted only six years. In this short time, it
managed to
become "one of the most devastating and well-documented
agricultural,
economic and social disasters in the history of the United
States,"
according to deMenocal.
Researchers need to gather more data on past climates before this
information can be used to accurately predict and design
strategies for
future large and persistent climate changes, says deMenocal, but
acknowledging the historic impact of these severe events is an
important
step toward that goal.
"Right now, we address climate change on the basis of a
painfully short
climate record, just the past 150 years or so that instruments
have
recorded," deMenocal says. "We now have to relearn
history on a long-term
scale."
© 2000 by the American Association for the Advancement of
Science
==========
(5) CULTURAL RESPONSES TO CLIMATE CHANGE DURING THE LATE HOLOCENE
From Science Online, 27 April 2001
http://www.sciencemag.org/cgi/content/full/292/5517/667?ijkey=qGELrNCbOuXAQ&keytype=ref&siteid=sci
Originally published in Science Express as
10.1126/science.1059188 on April
12, 2001
Science, Vol. 292, Issue 5517, 667-673, April 27, 2001
Cultural Responses to Climate Change During the Late Holocene
Peter B. deMenocal
Modern complex societies exhibit marked resilience to
interannual-to-
decadal droughts, but cultural responses to
multidecadal-to-multicentury
droughts can only be addressed by integrating detailed
archaeological and
paleoclimatic records. Four case studies drawn from New and Old
World
civilizations document societal responses to prolonged drought,
including
population dislocations, urban abandonment, and state collapse.
Further
study of past cultural adaptations to persistent climate change
may provide
valuable perspective on possible responses of modern societies to
future
climate change.
Lamont-Doherty Earth Observatory of Columbia University,
Palisades, NY
10964, USA. E-mail: peter@ldeo.columbia.edu
In the spring of 1785, the geologist James Hutton presented a
lecture to the
Royal Society of Edinburgh that changed scientific inquiry into
natural
processes. The essence of his view was simple enough: The present
is the key
to understanding the past. Hutton recognized that slow geologic
processes
such as erosion or uplift could produce sedimentary strata or
mountain
ranges. In 1795, he wrote that "we find no vestige of a
beginning--no
prospect of an end. ... Not only are no powers to be employed
that are not
natural to the globe, no actions to be admitted of except those
of which we
know the principle and no extraordinary events to be alleged in
order to
explain a common experience ..." (1). This view was not
accepted by most
natural scientists at the time because it required full
acceptance of the
expanse of geologic time and rejection of the prevalent views of
a young
Earth. Future generations of scientists, however, most notably
Charles
Darwin half a century later, were encouraged by this new way of
thinking to
interpret their observations on the basis of what they knew of
modern
processes.
To understand how and why climates change, we have to invoke a
corollary to
Hutton's view: The past must be used to understand the present.
Modern
instrumental records are sufficiently long to document climate
phenomena
that vary at interannual time scales, such as El Niño, but they
are too
short to resolve multidecadal- to century-scale climate
variability that we
know to exist from detailed tree-ring, coral, and lake sediment
records
spanning the past 500 to 1000 years (2, 3). Similarly, the
socioeconomic
impacts of recent El Niño/La Niña events are well documented
(4), but little
is known about the societal impacts of longer period climatic
excursions.
Without knowing the full range of climatic variability at time
scales of a
few decades to a few millennia, it is difficult to place our
understanding
of modern climate variability, and its socioeconomic impacts,
within the
context of how Earth climate actually behaves, both naturally and
as a
result of anthropogenic increases of greenhouse gasses (3).
Historic and Prehistoric Drought in North America
Excellent examples of the value of past climate records can be
gleaned from
the history of drought in the United States. Water availability,
rather than
temperature, is the key climatic determinant for life in semiarid
expanses
across the planet. Drought often conjures up images of the Dust
Bowl drought
of the 1930s, which lasted ~6 years (1933-38) and resulted in one
of the
most devastating and well-documented agricultural, economic, and
social
disasters in the history of the United States. The drought was
triggered by
a large and widespread reduction in rainfall across the American
West,
particularly across the northern Great Plains (5). It displaced
millions of
people, cost over $1 billion (in 1930s U.S. dollars) in federal
support, and
contributed to a nascent economic collapse. Subsequent analysis
of the Dust
Bowl drought has revealed that its tremendous socioeconomic
impact was, in
part, due to wanton agricultural practices and overcapitalization
just
before the drought, when rainfall had been more abundant (5). A
subsequent
decadal-scale drought in the 1950s (Fig. 1, A and B) was also
severe but
less widespread, mainly impacting the American Southwest, where
improved
land use practices and disaster relief programs mitigated its
effects.
How did the 1930s and 1950s droughts compare with other historic
and
prehistoric droughts? In a comprehensive analysis of hundreds of
tree-ring
chronologies from across the United States, Cook and others
established a
network of summer drought reconstructions extending back to 1200
A.D. (6, 7)
(Fig. 1A). This reconstruction documents much more persistent
droughts
before the 1600s (7). These so-called "megadroughts"
were extremely intense,
persisted over many decades, and recurred across the American
Southwest
roughly once or twice every 500 years (Fig. 1, A through D).
Reconstructed
conditions during the largest of these multidecadal droughts far
surpassed
those during droughts recorded within the past ~150 years (the
period for
which extensive instrumental data are available). Evidence for
these and
other megadroughts has been found in detailed lake sediment
records (8),
with additional evidence for even longer, century-scale droughts
in
California before 1350 and 1110 A.D. (9).
The most severe drought in the southwestern United States within
the past
800 years spanned an ~22-year period between 1572 and 1593 A.D.
(7) (Fig.
1C). The reconstructed spatial drought pattern at the peak of
this dry
period in 1583 A.D. shows extreme drought conditions extending
across the
American Southwest (Fig. 1C). Dry conditions apparently extended
eastward
and persisted into the early 1600s as far east as coastal
Virginia (10). On
the basis of a 700-year tree-ring chronology from northeastern
Virginia,
Stahle et al. conclude that the intervals spanning 1587 to 1589
A.D. and
1606 to 1612 A.D. were the driest periods in the past 700 years
(10). In
August of 1587 A.D., the first English colonists arrived and
settled in
Roanoke, Virginia. This small group of settlers became known
subsequently as
the Lost Colony, because the entire Roanoke settlement had
vanished by the
time the English resupply ships returned 4 years later.
Originally
attributed to poor planning and inadequate supplies, the failure
of the
Roanoke settlement is now understood within the context of this
severe
drought, which began, to their monumental bad luck, just when the
settlers
arrived (10). A larger colonial settlement was established
subsequently in
Jamestown, Virginia, in April of 1607 A.D., and the settlers also
suffered
greatly. Within 25 years, over 80% of the population died, mainly
of
malnutrition (10).
Although appreciably less severe than the drought of the 1580s,
the 26-year
"Great Drought" of the 1280s (11) was similarly
prolonged and widespread
(Fig. 1D). By the time of this drought, the Anasazi, ancestors of
modern
Pueblo Indians, had long established elegant stone and adobe
villages in the
semiarid highlands and canyons of the American Southwest.
Archaeological
investigations of Anasazi settlements have documented that many
sites were
abandoned abruptly near the end of the 13th century A.D. Cited
reasons for
the collapse of the Anasazi include emergent balkanization,
warfare, and
religious turmoil within the region, as well as the onset of
severe drought
conditions and regional deforestation (11, 12). Whether the
multidecadal
drought of the 1280s was the determining factor in the collapse
of the
Anasazi continues to be debated (13, 14), but current
archaeological
evidence firmly implicates drought as a contributing
destabilizing factor
(12, 14).
Modes and Mechanisms of Holocene Climate Variability
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 (15). The Holocene was once
thought to have
been climatically stable (16), but detailed and well-dated
paleoclimate
records now show that Holocene climate was punctuated by several
widespread
cooling events, which persisted for many centuries and recurred
roughly
every 1500 ± 500 years (17-22) (Fig. 2).
Paleoceanographic data indicate that these events were associated
with
changes in subpolar (19) and subtropical (21, 22) surface ocean
circulation
(Fig. 2), as well as marked changes in terrestrial climates (17,
18, 23,
24). These events appear to have occurred synchronously across
the North
Atlantic (21), with possible antiphase behavior in the northwest
Atlantic
(25). Deep-sea sediment evidence for deep-ocean circulation
changes
associated with these Holocene events is, at present, equivocal
(19, 26),
although other supportive evidence has been presented (20, 27,
28). The
millennial-scale pacing of Holocene climate variability
implicates
mechanisms with long time constants, such as thermohaline
circulation or
ocean-atmosphere coupling (26, 29), which govern modern climate
stability.
Analysis of the most recent millennial-scale Holocene climate
cycle, the
Little Ice Age [circa (ca.) 1300 to 1870 A.D.] and the preceding
Medieval
Warm Period (ca. 800 to 1300 A.D.), suggests that the primary
factors
affecting global temperature variability over the past millennium
were
variations in solar irradiance and volcanism, which together
account for 40
to 60% of the reconstructed temperature variability (30). Climate
models
require an additional forcing agent, the anthropogenic rise in
greenhouse
gases, to account for 20th-century warmth (30, 31). Strong
correlations of
solar irradiance variability (32, 33) with surface temperature
(30, 31) and
regional drought (34, 35) over the past millennium implicate
solar
variability as an important factor influencing global climate
over
multidecadal-to-multicentury time scales. However, the role of
solar
variability in forcing the full suite of millennial-scale climate
variations
during the Holocene (and the last glacial) is complicated by the
absence of
1500 ± 500 year variability in the atmospheric 14C record (36)
and its
generally inconsistent match with Holocene climate anomalies
(Fig. 2). The
14C record does exhibit substantial variance at periods near 2200
to 2500
years [the Hallstadzeit cycle (36)].
Cultural Responses to Late Holocene Climate Variations
How did past cultures respond to the longer, multicentury-scale
climate
changes that punctuated late Holocene climate? Placing the
archaeological
record of cultural change within the context of detailed and
well-dated
Holocene paleoclimate records presents opportunities to examine
how large,
complex societies responded to long-term, persistent changes in
climate. At
some times during the late Holocene, whole empires collapsed and
their
people were diminished to much lower subsistence levels, whereas
in other
cases, populations migrated and adapted to new subsistence modes.
In all
cases, the observed societal response reflects an interaction
between human
cultural elements (socioeconomic, political, and secular
stresses) and
persistent multicentury shifts in climate. Four case studies
drawn from the
joint archaeological and paleoclimate histories of the New and
Old World
illustrate past cultural responses to late Holocene climate
change: the
collapse of the Akkadian (ca. 4200 calendar yr B.P.), Classic
Maya (ca. 1200
calendar yr B.P.), Mochica (ca. 1500 calendar yr B.P.), and
Tiwanaku (ca.
1000 calendar yr B.P.) empires.
Akkadian collapse (Mesopotamia, ca. 4200 calendar yr B.P.). Under
the rule
of Sargon of Akkad, the first empire was established between ca.
4300 and
4200 calendar yr B.P. on the broad, flat alluvial plain between
the Tigris
and Euphrates Rivers (37). Akkadian imperialization of the region
linked the
productive but remote rain-fed agricultural lands of northern
Mesopotamia
with the irrigation agriculture tracts of southern Mesopotamian
cities.
After ~100 years of prosperity, however, the Akkadian empire
collapsed
abruptly at ca. 4170 ± 150 calendar yr B.P. (37, 38).
Archaeological
evidence documents widespread abandonment of the agricultural
plains of
northern Mesopotamia (37) and dramatic influxes of refugees into
southern
Mesopotamia, where populations swelled (37, 39) (Fig. 3). A
180-km-long
wall, the "Repeller of the Amorites," was built across
central Mesopotamia
to stem nomadic incursions to the south. Resettlement of the
northern plains
by smaller, sedentary populations occurred near 3900 calendar yr
B.P., ~300
years after the collapse (37). The stratigraphic level
representing the
collapse at Tell Leilan, northeast Syria, is overlain by a thick
(~100 cm)
accumulation of wind-blown silts, which was devoid of artifacts
(37),
suggesting a sudden shift to more arid conditions. Social
collapse evidently
occurred despite archaeological evidence that the Akkadians had
implemented
grain storage and water regulation technologies to buffer
themselves against
the large interannual variations in rainfall that characterize
this region
(37).
Using a deep-sea sediment core from the Gulf of Oman, Cullen et
al. (40)
reconstructed a detailed record of Holocene variations in
regional dust
export based on mineralogical and geochemical tracers of
wind-borne
sediments from Mesopotamian sources (Fig. 4). Closely dated by a
sequence of
calibrated radiocarbon dates, the Gulf of Oman core documents a
dramatic
~300-year increase in eolian dolomite and carbonate, which
commenced at 4025
± 125 calendar yr B.P. Isotopic (87Sr/86Sr) analyses demonstrate
that the
increased eolian dust was derived from Mesopotamian sources (40)
(Fig. 4).
Geochemical similarity of volcanic tephra shards found at Tell
Leilan and in
the deep-sea sediment core provided further evidence that the
Akkadian
collapse and climate change events were synchronous (40).
Enhanced regional
aridity is also indicated by increased eolian quartz deposition
in nearby
Lake Van at the headwaters of the Tigris River (41) and by
paleoclimate
records from the Levant (42). The combined archaeological and
paleoclimate
evidence strongly implicates abrupt climate change as a key
factor leading
to the demise of this highly complex society.
The onset of sudden aridification in Mesopotamia near 4100
calendar yr B.P.
coincided with a widespread cooling in the North Atlantic (19,
21). During
this event, termed Holocene Event 3 (Fig. 2), Atlantic subpolar
and
subtropical surface waters cooled by 1° to 2°C (19, 21). The
headwaters of
the Tigris and Euphrates Rivers are fed by elevation-induced
capture of
winter Mediterranean rainfall. Analysis of the modern
instrumental record
shows that large (50%) interannual reductions in Mesopotamian
water supply
result when subpolar northwest Atlantic sea surface temperatures
are
anomalously cool (43). The aridification of Mesopotamia near 4100
calendar
yr B.P. may thus have been related to the onset of cooler sea
surface
temperatures in the North Atlantic.
Classic Maya collapse (Yucatán Peninsula, ca. 1200 calendar yr
B.P.). The
Preclassic Maya culture occupied vast lowland and highland
regions of
Mesoamerica from the second millennium B.C. to ca. 250 A.D. The
onset of the
Early Classic period after 250 A.D. marks the rapid growth of a
more
complex, stratified, and intellectually and artistically prolific
empire.
The hallmark accomplishments of Early (250 to 550 A.D.) and
especially Late
(550 to 850 A.D.) Classic Maya cultures include the development
of trade
networks spanning Mesoamerica, expansive urban centers, the
erection of
monumental stelae, and advances in astronomy and mathematics
(44).
The Classic Maya empire collapsed at the peak of their cultural
development
between ca. 750 and 900 A.D., as determined by the number of
sites engaged
in monument construction across Mesoamerica at any given time
(45) (Fig. 5).
Following the apex of monument construction in 721 A.D., signs of
collapse
began to show between 750 and 790 A.D. Construction effectively
ceased
throughout the region after 830 A.D., and in 909 A.D., the last
monument in
southern Quintana Roo, Mexico, was inscribed with the Maya Long
Count date
(44). Many reasons for the collapse have been cited, including
overpopulation, deforestation and soil erosion, social upheaval,
warfare,
and disease, as well as natural phenomena, such as climate change
(46, 47).
Deforestation, erosion, and dense human occupation are
well-documented in
many regions before the collapse (46, 48, 49).
The first unambiguous evidence for the role of climate change in
the
collapse of the Classic Maya (50) came from lake sediments, which
documented
an abrupt shift to more arid conditions in the central Yucatán
Peninsula
(Mexico) between 1300 to 1100 calendar yr B.P. (800 to 1000 A.D.)
(Fig. 6).
Sediment composition and stable isotopic analyses of ostracode
shells
preserved in sediment cores from the closed-basin Lakes
Chichancanab (50)
and Punta Laguna (51) in the central Yucatán indicate that the
region was
subjected to an ~200-year period of persistently arid and highly
evaporative
conditions centered near 1200 calendar yr B.P. (900 A.D.) (Fig.
6).
The densely populated southern lowlands of the Yucatán Peninsula
were highly
reliant on surface water supplies for human and agricultural
needs, and it
was these regions that were most acutely affected during the
drought from
800 to 1000 A.D. Archaeological excavations estimate that lowland
population
densities decreased from ~200 persons/km2 at the peak of the Late
Classic
period to less than 100 persons/km2 by ca. 900 A.D.; by 1500
A.D., many
watersheds had been completely abandoned (48). An additional dry
period
predating the collapse was noted at 580 A.D. in the higher
resolution core
record from Lake Punta Laguna (51) (Fig. 6). This century-scale
dry period
coincides with the Maya Hiatus at the Early/Late Classic Maya
boundary, when
monument construction was briefly curtailed (from ca. 530 to 650
A.D.) (44,
45, 48).
Moche IV-V Transformation (coastal Peru, ca. 1500 calendar yr
B.P.).
Pre-Columbian coastal and highland Peruvian civilizations offer
exceptional
insight into past linkages between culture and climate change
because they
sustained densely populated, complex, agrarian cultures in very
challenging
environments. The Peruvian coast is extremely arid and requires a
high
reliance on irrigation to support agriculture, yet these regions
sustained
large populations for many centuries.
Known for their sophisticated metallurgy and monumental adobe
brick
structures, the Mochica polity established urban centers and
controlled the
entire northern Peruvian coastline south of the Sechura desert
from ca. 300
to 500 A.D. (early Moche IV period) (52). One such locality, the
capital
site of Moche, boasts the largest adobe structure in the New
World, the
Huaca del Sol (52). This immense coastal site and the cities it
served were
very abruptly abandoned near 600 A.D. Archaeological evidence
shows that
main irrigation channels had been overrun by sand dunes at the
time of
abandonment. The subsequent Moche V culture was reestablished
farther
inland, near the confluence of highland rivers draining the
Andean
foothills, where runoff was more dependable, between 600 and 750
A.D. The
Moche IV-V Transformation was unprecedented in scope, scale, and
rapidity
for this region (52).
An annual resolution record of regional precipitation changes
from the
Quelccaya ice core (Peru) firmly implicates climate change as a
leading
factor underlying the Moche IV-V Transformation (52). Variations
in oxygen
isotopes, accumulation rate, and insoluble particle concentration
in this
ice core document large changes in regional climate spanning the
past 1500
years, which can be used to place the cultural records within
their
paleoclimatic contexts (52, 53). Comparison of the paleoclimatic
and
cultural histories indicates that the Moche IV-V Transformation
near 600
A.D. was immediately preceded by an ~30-year period of reduced
regional
precipitation (lower ice accumulation between 563 and 594 A.D.)
and
corresponded with an ~60-year interval of increased wind-borne
particles in
the ice (Fig. 7).The loss of Moche IV coastal irrigation channels
to
encroaching sand dunes and the population migration to the better
watered
highland valleys are consistent responses to the enhanced
regional aridity
indicated by the ice core (52). Paulsen (54) recognized several
coastal to
highland population shifts throughout the first and second
millennium A.D.
(Fig. 7), noting a general seesaw relation between the rise and
fall of
coastal and highland agrarian cultures in both Peru and Ecuador.
As
discussed by Thompson et al. (53), these ancient coastal to
highland
population shifts closely corresponded with the largest ice
accumulation
(precipitation) changes recorded in the Quelccaya ice core record
(Fig. 7).
Of particular paleoclimatic interest is the evidently synchronous
onset of
arid conditions in the tropics of both hemispheres (Peru and the
Yucatán)
near 900 and 600 A.D. (51) (Figs. 6 and 7).
Tiwanaku collapse (Bolivian-Peruvian altiplano, ca. 1000 calendar
yr B.P.).
The Tiwanaku culture thrived for nearly 1500 years (300 B.C. to
1100 A.D.)
in urban and rural agrarian settings surrounding Lake Titicaca in
the
southern Bolivian-Peruvian altiplano (~4000-m elevation) (55,
56). Through
the ingenious use of raised field cultivation, which promotes
efficient
nutrient recycling and uses irrigation canals to thermally buffer
crops
against killing frosts, the Tiwanaku were able to sustain an
urban complex
with an estimated population of nearly half a million people
(55). The
massive urban center at Lake Titicaca served as the capital of an
expanding
state society that eventually exploited regions extending to the
Peruvian
coastal desert and foothills.
The densely settled Tiwanaku urban centers and raised fields were
abandoned
abruptly near 1100 A.D. (55, 56). Full collapse of the Tiwanaku
state
occurred over the 12th to 15th centuries. The Quelccaya ice core
was drilled
just 200 km northwest of Lake Titicaca (53) and thus provides
valuable
insight into the paleoclimatic contexts of the Tiwanaku
abandonment and
collapse. Comparison of the Tiwanaku cultural changes with the
Quelccaya
isotopic and ice accumulation records shows a close coincidence
between the
abandonment and the onset of increasingly arid conditions (lower
ice
accumulation rate) (Fig. 7). Conditions markedly drier than those
of today
persisted for several centuries, commencing after 1040 A.D. (53).
Sediment
cores from Lake Titicaca document an ~10-m drop in lake level at
this time
(56). It has been proposed that the sudden onset and multicentury
persistence of more arid conditions would have dramatically
impacted the
productivity of the raised field agriculture system and,
consequently, its
ability to sustain swelling Tiwanaku urban and rural populations
(53, 55,
56).
Past Cultural Responses to Climate Change
What can be learned from these ancient cultural responses to
prolonged
drought? The climatic perturbations associated with these late
Holocene
societal dislocations were extreme in their duration and
intensity, far
surpassing droughts recorded during the modern instrumental
period. As shown
in Fig. 1A, interannual droughts occur many times within a given
generation,
and decadal droughts recur infrequently across many generations.
Multidecadal to multicentury scale droughts are much rarer but
are
nonetheless integral components of natural climate variability.
Well-dated
and detailed paleoclimate records from climatically sensitive
locations bear
witness to the occurrence and severity of these
multidecadal-to-multicentury
droughts (Figs. 2, 4, and 6).
For the examples discussed above, available paleoclimate and
archaeological
data show that societal collapse and prolonged drought were
coincident
within respective dating uncertainties. Coincidence alone cannot
demonstrate
causality; indeed, each of these cultural collapses had been at
one time
interpreted solely in terms of human factors unrelated to natural
climate
variability, such as warfare, overpopulation, deforestation, and
resource
depletion. However, joint interpretation of the paleoclimatic and
archaeological evidence now underscores the important role of
persistent,
long-term drought in the collapse of the Akkadian (37, 39, 40),
Maya (46-48,
50), Mochica (52, 53), and Tiwanaku (53, 55, 56) civilizations.
These
examples show that, challenged by unprecedented environmental
stresses,
cultures can shift to lower subsistence levels by reducing social
complexity, abandoning urban centers, and reorganizing systems of
supply and
production (39).
Recalling James Hutton's uniformitarian premise, what makes these
ancient
events so relevant to modern times is that they simultaneously
document both
the resilience and vulnerability of large, complex civilizations
to
environmental variability. Complex societies are neither
powerless pawns nor
infinitely adaptive to climate variability. As with modern
cultures, the
ancients adapted to and thrived in marginal environments with
large
interannual climate variability. As with ancient cultures, modern
civilizations (regrettably) gauge their ability to adapt to
future climate
variations on the basis of what is known from historical (oral or
instrumental) records. What differentiates these ancient cultures
from our
own is that they alone have witnessed the onset and persistence
of
unprecedented drought that continued for many decades to
centuries. Efforts
to understand past cultural responses to large and persistent
climate
changes may prove instructive for assessing modern societal
preparedness for
a changing and uncertain future (57).
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Fig. 1. This manuscript greatly benefited from discussions with
E. Cook, D.
Hodell, and M. Brenner. Critical reviews were provided by H.
Weiss, O.
Bar-Yosef, E. Cook, and two anonymous reviewers.
10.1126/science.1059188
Include this information when citing this paper.
Volume 292, Number 5517, Issue of 27 Apr 2001, pp. 667-673.
Copyright © 2001 by The American Association for the Advancement
of Science.
====================
(6) TIME'S WARMING RETREAT
From New York Post, 24 April 2001
http://www.nypostonline.com/postopinion/opedcolumnists/29108.htm
IT took a reader to remind Time magazine of the basic flaw in
"Feeling the
Heat," its April 9 environmental manifesto on global warning
- and to win an
important admission from the report's author.
The piece warned: "Except for nuclear war or a collision
with an asteroid,
no force has more potential to damage our planet's web of life
than global
warming. It's a 'serious' issue, the White House admits, but
nonetheless
George W. Bush has decided to abandon the 1997 Kyoto treaty to
combat
climate change . . ."
The point of that, and several companion pieces, was clear: Earth
is in
imminent danger, thanks to pollution and other man-made sources,
but the new
president is wearing blinders.
In case anyone missed the point, the magazine this week
highlights a letter
that thanks Time for its report and adds: "I hope someone
reads it to George
W. Bush."
But several readers disputed the magazine's basic argument. The
lead graphic
on April 9, spread out over two pages, charted the "world of
offenders" on
CO2 emissions, and another made suggestions on "How to Ward
Off Disaster,"
yet Tom Peterson of Salt Lake City noted:
"Nature emits about 95 percent of greenhouse gases, while
humans are
responsible for only 5 percent. Add a volcanic eruption here and
there, and
nature probably accounts for as much as 99 percent. . . . With
the rise of
our industrial might, temperatures haven't risen at all."
How did Time counter this assault on its basic premise, that
humans are
destroying the environment? Associate Editor Michael Lemonick
agreed that
"nature is responsible for most of the greenhouse gases on
Earth."
However, Lemonick insisted, "even the small percentage that
is man-made . .
. has been enough to start nudging temperatures upward."
Which is not quite
what Time argued in the first place, which is that humans are the
prime
culprit.
Said Time then: There is "powerful" evidence to support
"the case of
human-induced global warming" and it is no longer
theoretical that "the
planet is warming up as a result of human activity."
============================
* LETTERS TO THE MODERATOR *
============================
(7) NO NOAH'S FLOOD
From Nils-Axel Mörner <Nils-Axel.Morner@pog.su.se>
Dear Benny,
Yes, the IPCC Chapter 11 is a very inferior product (written by
33 persons,
in no way being specialist on the task). The real sea level
specialists
would NEVER give these statements, figures and interpretations.
The remarkable thing is that they themselves arrived at 0.8 mm/yr
rise in
the future, but refused to accept this figure and turned to theri
modelling,
instead. So, their figure is purely a model output. We, sitting
on the
empirical observation data do certainly dissagree. Also, their
rates and
amplitudes of changes do not concur with known processes and
geophysics of
the Earth.
In order not just to object, we launched a specific research
project in the
Maldives. No doubt, sea level there has NOT gone up a singe mm in
the last
150 years; instead it has fallen significantly in the last 20-30
years.
Please consult our INQUA webb-page: www.pog.su.se/sea and our
institutionan webbpage: www.pog.su.se
and my papers in "Integrated Coastal
Zone Management", 2000 (Spring & Autumn Editions).
With all the best wishes
Niklas
----------
MODERATOR'S NOTE: Professor Mörner is the President of the INQUA
Commission
on "Sea Level Changes and Coastal Evolution", the
international body
representing the scientific community of sea level researchers.
It is
enlightening to read what he has to say about the dire prediction
made by
the IPCC regarding catastrophic sea level rises (see
http://www.pog.su.se/sea/):
"Chapter 11 on "Sea Level Changes" of IPCC's 1999
TAR paper was
written by 33 persons; none of whom represents actual sea level
research. I have now finished a 7 pages review report. It is a
most
shocking reading; lots of modeler wishes but very little hard
facts based on
real observational data by true sea level specialists. I allow
myself a few
quotations.
"It seems that the authors involved in this chapter were
chosen not
because of their deep knowledge in the subject, but rather
because they
should say what the climate model had predicted".
"This chapter has a low and unacceptable standard. It should
be
completely rewritten by a totally new group of authors chosen
among
the group of true sea level specialists".
"My concluding proposition is: (1) Dismiss the entire group
of
persons responsible for this chapter, (2) Form a new group based
on real
sea level specialists (e.g. INQUA), and (3) Let this group work
independently of climate modeler".
IPCC and Sea Level Change
(as a part of IPCC WG1 Third Assessment Report, I was asked as
"Expert Reviewer" to comment on Chapter 11
"Changes in Sea Level". In my
previous review of December 15, I gave numerous comments and deep
criticism of the handling of the Sea Level problems and facts. It
is
extremely frustrating to note that there are very little
recognition of
these comments and still, they come from the President of the
INQUA
Commission on "Sea Level Changes and Coastal
Evolution", i.e. the
international body that hosts all the front scientists in
Quaternary
sea level research and from where most of the observational
records emerge.
Ignoring our group is to ignore observations and put all trust
in
modelling. This is a serious mistake that deserves nothing but
discredit.
National sovereignty is a basic concept in international
relations.
It must be respected. In science, we may speak about a
"subject
sovereignty" and demand that the true specialists and
representatives of a
subject also should be the first to answer questions about this
subject. Neglecting to do so is to violate scientific decency. In
the
case of Chapter 11 (Changes in Sea Level), this is exactly what
is
being done. The true sea level specialists are left outside, and
the
chapter is instead written by persons representing quite other
disciplines.
This is not acceptable. Only we, the representatives of the
international sea level community (with our INQUA commission in
clear
leading position), are true producers of field observational
facts. Why
do we see no single one from this community among the
contributors to this
chapter? The situation is absurd. Modellers output data now
appear in the
text as input data. This is nothing but falsification of
scientific
observational facts."
Nils-Axel Mörner
======
(8) NOAA'S FLOOD
From Jonathan Shanklin <jdsh@bas.ac.uk>
If readers would like to judge for themselves on the recent
change of sea
level in the Maldives, data from the the GLOSS network is
available at
http://www.pol.ac.uk/psmsl/psmsl.monthly.html
Click on the P option under GAN and MALE
Regards,
Jonathan Shanklin
j.shanklin@bas.ac.uk
British Antarctic Survey, Cambridge, England
http://www.nerc-bas.ac.uk/public/icd/jds
==========
(9) CORAL ISLAND, SEA LEVELS & ASTEROID IMPACTS
From Duncan Steel <D.I.Steel@salford.ac.uk]
Dear Benny,
The final item in CCNet today (April 26) contained this
paragraph:
One litmus location has been the Maldives Islands in the centre
of
the Indian Ocean, a coral group, which the IPCC says will drown
under
rising seas within a few decades (IPCC TAR chapter 11).
This concept of coral islands being drowned by sea level rise has
always
confused me. Surely coral grows at only certain depths, and so in
broad
scope it simply keeps step with any rise in sea level? Of course
the
situation for specific island formations will be more complicated
than my
flippant rhetorical question, but clearly any assumption
that such islands
are entirely unchanging whilst the sea swallows them up is
invalid.
One might also like to muse on the irony that coral is largely
made of
calcium carbonate, so that any rise in sea level stimulating
coral growth
has the effect of locking up more carbon dioxide in a rocky form.
In various
places, the US in particular, artificial reefs have been
constructed by
dumping old tyres and car bodies in shallow water. Maybe we
should be
shipping such waste to the tropical oceans, throwing it overboard
in places
where the water is only slightly too deep for coral to thrive.
Then the
garbage would provide new sites for coral islands to grow, at the
same time
sucking up lots of carbon dioxide.
Oh, there is also a link between coral islands and asteroid
impacts. After
he returned from his famous voyage on the Beagle in the 1830s,
Charles
Darwin wrote a nice little book about coral atolls, describing
how
near-circular coral reefs form around oceanic rock outcrops.
Thus, looking
down from above, there is a central uplift with a circular rim
surrounding
it. Late in the 1840s Charles Babbage suggested that this was the
origin of
the craters on the Moon: coral atolls left high and dry after the
lunar
"seas" (maria) lost their water.
Duncan Steel
===========
(10) CLIMATE RESEARCH AND CONSPIRACY THEORIES
Andrew Glikson <geospec@webone.com.au>
Dear Benny,
In your CCNet item of 25-04-01 you state "Equally
intimidating are
accusations that CCNet has given the impression as if greenhouse
warming is
a mere conspiracy theory (reminiscent of UFO
cover-up conspiracy theories) invented by sinister forces to
frighten
innocent citizens. To the best of my knowledge, I cannot recall
that I have
ever posted any conspiracy theories on CCNet." (B.
Peiser, 25-04-01).
This comment responds to my communication of the same date, where
I stated:
"Before any CCNet reader obtains an impression as if
greenhouse warming is a
mere conspiracy theory invented by sinister forces to frighten
innocent
citizens, as alleged by some (CCNet 20-04-01), consider that:
...etc."
Note that my communication (25-04-01) refers to highlighted CCNet
headlines
(20-04-01) which cite M. Phillips' (The Sunday Times, 15-04-01)
statement:
"Every age has a governing creed from which dissenters are
branded heretics
or enemies of the people. Once it was that God created the world.
Next it
was that man had to recreate the world as the workers' paradise.
When
communism imploded in the late 1980s another belief emerged to
fill the gap
- that mankind was destroying the world through global warming.
Anyone who
questions the orthodoxy that the West's rising output of carbon
dioxide will
produce environmental catastrophe is branded as mad, bad or in
the pay of
the oil industry. [...] There is no conclusive evidence to
support the
global warming theory., etc.".
Inherent in the above-cited statement is the insinuation as if
the results
of climate research constitute some kind of ideologically
motivated dogma,
casting doubt on the integrity and honesty of the scientists and
scientific
organizations involved in climate research. The highlighting of
such a
damaging allegation, which reflects on the reputation of numerous
serious
researchers, in the headlines of CCNet, must be questioned - in
the very
least, equal highlighting must be given to refutation of such
misrepresentation and to counter points of view.
Selective citation highlighting, title rewording and use of terms
such as
"scare", "alarm" etc. (commonly used in
connection with climate change, but
less so in connection with asteroid risks) can only result in an
impression
of an ideological preference. Such methods, extensively used in
the popular
and political press, have no place in "scholarly electronic
networks".
Sincerely
Andrew Glikson
26-04-01
MODERATOR'S NOTE: Dear Andrew,
I accept your criticism that I select citations which I prefer,
reword
titles according to my sense of humour and even brand
unsubstantiated alarms
as a "scare". These are normal working practices of
editors and moderators,
not just in the world of the political press but also in the
scientific
media. You just need to look at the alarmist tone and often
biased coverage
of the global warming issue in journals such as New Scientist,
Science and
Nature.
I can understand if you occasionally dislike my sceptical tone
and bias or
the selection of a piece of information which I find particularly
enlightening. However, I always try to present *all*
observational evidence
and sound arguments in the global warming debate. Please hit back
at me if
you feel that I deliberately ignore or supress any relevant data
or evidence
- but don't blame me for being critical of doomsday prophecies.
In the context of your complaint, it is evident that Melanie
Phillips'
accusations had nothing to do with conspiracy theories, nor was
it directed
at "the" results of climate research. Instead, she
criticised those who have
hijacked climate research for political purposes while claiming
that
"mankind [is] destroying the world through global
warming." She also pointed
out that there is no scientific consensus regarding at least two
vital
issues: i) that the current warming trend is mainly due to
man-made
emissions of greenhouse gases, and ii) that this trend will lead
to global
catastrophes.
As the moderator of a very public network that focuses on *all*
aspects of
neo-catastrophism and which is read by thousands of people
around the
world, I feel it is my responsiblity to strike a balance between
realistic
and exaggerated risk perception and hazard assessment. I hope you
will
understand that, for the time being, I remain a sceptic.
Benny J Peiser
===========
(10) CLIMATE RESEARCH AND CONSPIRACY THEORIES II
From Max Wallis <wallismk@Cardiff.ac.uk>
I agree with Andrew Glikson in CCNet CLIMATE SCARES & CLIMATE
CHANGE, 25
April 2001 that CCNet has given the "impression as if
greenhouse warming is
a mere conspiracy theory (reminiscent of UFO cover-up conspiracy
theories)
invented by sinister forces to frighten innocent citizens."
I've told Benny
as much in the past with examples.
It takes little skill in linguistic analysis of Benny's answer,
that "CCNet
is an open forum in which all sound arguments regarding the
greenhouse
warming scare will get a fair hearing" to see various
biases, especially in
use of the term SCARE. And in introducing Fred Singer as an
"eminent
researcher and CCNet contributor" rather than longstanding
critic of the
IPCC.
What of Benny's citing Singer's twelve "major scientific
problems"?
Problem 7 is undoubtedly scientific:
"Severe storms and hurricanes have diminished in the past 50
years. A global
warming trend is calculated to reduce the latitudinal temperature
gradient
and therefore the driving force for storms and severe
weather."
Problem 11 is technically uncontrovertible (no problem!)
"mitigation techniques are available that can slow down the
rise of
atmospheric GH gases and a possible climate change: energy
conservation and
increased efficiency often make economic sense.." but drifts
into the
socio-economic problem of why some mitigation techniques that are
'economic'
are not taken up.
Problem 9 is little more than a guess, showing the bias of a
physical
scientist:
" The spread of disease vectors, like malaria-carrying
mosquitos, is likely
to be unimportant in comparison to human vectors."
Problem 12 seems to be a free-market modification of the
Precautionary
Principle, so way beyond the normal definition of a scientifc
problem:
"Policy measures should be applied with great caution and
only when
justified by scientific data."
It's this confusion of legitimate scientific questioning of the
greenhouse-climate theory mixed up with overt or covert social,
ethical and
political biases that justifies Glikson's analogy with UFO
cover-up
conspiracy theories.
Hold up your hands, Benny!
Max Wallis
Cardiff Centre for
Astrobiology wallismk@cf.ac.uk
67 Park
Place
tel. 029 2087 6426
Cardiff University CF10
3AS
fax 029 2087 6425
===========
(11) AND FINALLY, IGNORE GLOOMY INTELLECTUALS AND LOOK AT THE
FACTS
From Reason Online, 25 April 2001
http://www.reason.com/rb/rb042501.html
Are we making progress? Ignore the gloomy intellectuals and look
at the
facts.
By Ronald Bailey
In some intellectual circles, it is fashionable to dismiss the
idea of
progress, the notion that social, political, and material
conditions for the
mass of humanity are getting better. Langdon Winner, a professor
at
Rensselaer Polytechnic Institute, recently asserted at the
International
Forum on Globalization's Teach-In on Technology and Globalization
that "all
indices of performance are improving, but the world is not
getting better."
He added that this "used to be called progress, which we
don't hear much
about anymore."
New York University social critic and author of Technopoly: The
Surrender of
Culture to Technology, Neil Postman once dismissively declared
that "America
has developed a new religion, as it were, and the religion is its
faith that
human progress and technological innovation are the same
thing." The ranks
of progress skeptics include such notables as Jacques Ellul,
Christopher
Lasch, Herbert Marcuse, Chellis Glendenning, Lewis Mumford,
Jeremy Rifkin
and many others.
Despite the skepticism of these and other disaffected
intellectuals, the
evidence supports the notion that there has indeed been a lot of
progress,
by which I mean substantial improvement in the quality of and
prospects for
human life. To be sure, we are not talking heaven on Earth. But
relative
improvement? Absolutely.
Let's review the evidence. Probably the most concrete measure of
progress is
the vast increase in human life expectancy over the past century.
Demographers believe that global life expectancy in 1900 was
around 30
years. By 1950 it had increased to 48 years. Today, global life
expectancy
is 66 years and is expected to rise to 73 years by 2025,
according to the
World Health Organization. The really good news is that the
difference in
life expectancy between the developed world and the
less-developed regions
of the globe has narrowed dramatically from more than 25 years in
the early
1950s to around 11 years today.
The burden of disease has also lifted considerably. The annual
number of
deaths among people under age 50 fell from 21 million in 1955 to
about 10
million in 1997. Deaths under 50 are expected to decline further,
to 5
million, by 2025. This is an extraordinary improvement in human
health since
world population in 1955 was 2.8 billion and is now over 6
billion.
For those worried about population growth, the average number of
children a
woman has over the course of her lifetime has dropped from just
under 6 in
1960 to 2.9 today. If current fertility trends continue, U.N.
population
figures suggest that world population is likely to top out at a
bit over 8
billion and begin to fall by the middle of this century. As
important, women
(and men, too, in their own fashion) have more control over their
fertility.
Widespread famines are thing of the past. Global food prices have
dropped by
50 percent since 1960 largely because food production increased
at faster
pace than population growth.
Between 1820 and 1992, the world's economies grew 40-fold. More
recently,
world gross domestic product tripled from $9.5 trillion in 1970
to $29
trillion in 1998. Average wages in America tripled in real terms
from $8 per
hour in 1949 to $24 per hour today. Without minimizing the
hardships that
many Americans face, the good news is that poverty in this
country isn't
what it used to be. Michael Cox, an economist at the Dallas
Federal Reserve
Bank, points out that of those households officially below the
poverty line,
97 percent have color TVs, and two-thirds live in air-conditioned
dwellings
and have microwaves. Seventy-five percent own VCRs and own at
least one car.
Forty-one percent own their own homes, and 50 percent own stereos
and almost
all have refrigerators and cooking stoves. The poor in the U.S.
today have a
higher standard of consumption than the average household did in
1971. (See
"Buying Time")
Humanity's inventiveness has exploded too. In 1790, when the U.S.
Patent
Office opened its doors, it granted just 3 patents. By 1882, the
Patent
Office had issued serial number 50,000 for its patent
applications. Of
course, the 19th century was the century which saw the invention
of the
steamboat, the railroad, the telegraph, the mass market
newspaper,
nitroglycerin, the germ theory of disease, chemistry and the
periodic table
of elements. In 1899, the year when patent serial number 700,000
was
assigned, the Commissioner of the U.S. Patent Office famously
recommended
that his office be abolished because "Everything that can be
invented has
been invented." How wrong he was is illustrated simply by
noting that at the
end of the year 2000, the patent serial number 9,471,932 had been
assigned.
In 1900, the few thousand existing automobiles were the expensive
toys of
the very rich. By 1950, there were 70 million vehicles. Today,
there are
more than 500 million-one for every 6 people on the planet.
In 1975, the United States had 200,000 of the world's total of
300,000
computers. Today there are 160 million computers in use in
America-51
percent of U.S. households have personal computers, up from 24
percent in
1994. Today, there are 557 million computers in use worldwide. In
the past
40 years, global computing power has increased a billion-fold. A
Ford Taurus
contains more computing power than the multi-million dollar
main-frame
computers used in the Apollo space program.
Today, the 100 million mobile phones used by Americans are
one-third of the
total 300 million mobile phones in use worldwide. By 2005, as
many as 1.6
billion people will be cell phone subscribers.
The internet is used by 423 million people and that is expected
to rise to
over 1 billion by 2005. Two years ago, former vice-president Al
Gore told
the American Association for the Advancement of Science annual
meeting that
there were only 4 websites when he took office. Now Google
searches
1,346,966,000 web pages.
Since 1970, 4,355 new drug applications have been filed with the
U.S. Food
and Drug Administration. And at the dawn of the 21st century,
scientists
have sequenced the human genome, and the genomes of many other
important
species, opening up fantastic possibilities for further improving
human
health and crop production.
Today, 92 percent of primary school age boys and 88 percent of
girls are in
school worldwide. Even in the lowest-income countries, the
comparable
figures are 89 percent for boys and 82 percent for girls.
Progress is not confined to the material and technological
sphere. Liberty
too has increased. First, one should keep in mind that the
centuries-old
evil of slavery was essentially abolished in the 19th century.
The 20th
century saw a dramatic increase in democratic governance.
According to
Freedom House, there were no nation-states that met its
definition for being
fully democratic in 1900. "The states with restricted
democratic practices,
not universal suffrage, were 25 in number and accounted for just
12.4
percent of the world's population. In 1900 monarchies and empires
predominated," notes Freedom House.
In 1950, there were 22 democracies, accounting for 31 percent of
the world's
population, and an additional 21 states had restricted democratic
practices,
accounting for 11.9 percent of the globe's population. Today, 120
of the
world's 192 countries are electoral democracies and constitute
62.5 percent
of the world's population. At the same time liberal
democracies--that is,
countries which Freedom House regards as free and respectful of
basic human
rights and the rule of law--are 85 in number and represent 38
percent of the
world's people.
MIT social critic Leo Marx once tendentiously asked, "Does
Improved
Technology Mean Progress?" Let's just say that the evidence
of history
strongly suggests that improved technology is a prerequisite for
progress,
both material and social. Before modern technology, poverty,
tyranny, and
ignorance were the lot of most people. Technology enables more
and more
people to pursue the humanitarian goals of justice, freedom, and
self-fulfillment than ever before.
Ronald Bailey (rbailey@reason.com)
is REASON's science correspondent and the
editor of Earth Report 2000: Revisiting the True State of the
Planet
(McGraw-Hill).
Copyright 2001, Reason Online
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