PLEASE NOTE:
*
CCNet, 76/2000 - 17 July 2000
------------------------------
"Attempting to promote the Torino
Scale as scientific,
necessarily runs into the problem of low
credibility. Everyone
knows that an announced risk of impact
will soon revert to a
measure of zero, so the shrewd
commentator will position him- or
herself with that expectation in mind.
And hence the 'giggle
factor' will remain a certain
companion."
-- Jens
Kieffer-Olsen, Slagelse, Denmark
"But the fact that 2000 NM was
found accidentally by an amateur
with a relatively small telescope
underscores the crucial role
that amateurs still play in the field of
astronomy - not to
mention acting as cosmic lookouts for
our planet. Someday, such a
discovery could help to save the Earth
from being blindsided by a
hurtling space rock similar to the one
that is thought to have
destroyed the dinosaurs. [...] It is
only through the dedicated
efforts of amateurs like [Leonard
Amburgey] in many countries,
Brian Marsden explained, that the orbits
of such asteroids can
be determined. Without their work, it
would be a much more
difficult, if not impossible, task to
determine whether there is
a rock out there with Earth's name on
it. Earth has been
pummeled in the past and someday,
astronomers say, there will be
another asteroid headed our way; it
might be tomorrow or a
million years from now."
-- David L.
Chandler, Boston Globe, 15 July 2000
"These bureaucrats have gone crazy.
Britain needs its own
astronomy facilities to train new
scientists. Jodrell Bank is
also still doing world-class research -
it would be a tragedy to
lose it." -- Patrick Moore, 16 July
2000
(1) 2000 NM: TEACHER'S TYPO POINTS HIM TO AN ASTEROID
The Boston Globe, 15 July 2000
(2) LINKS TO ASTEROID 2000 NM STORY
Daniel Fischer <dfischer@astro.uni-bonn.de>
(3) GUYRA METEORITE
Colin Keay <phcslk@cc.newcastle.edu.au>
(4) BLEAK OUTLOOK FOR UK ASTRONOMY: MORE OBSERVATORIES TO BE
CLOSED
The Sunday Times, 16 July 2000
(5) WHY NEOS ARE BOUND TO BE MISSED IN JULY & AUGUST
David Tholen <tholen@IfA.Hawaii.Edu>
(6) TORINO SCALE HAS A CREDIBILITY PROBLEM
Jens Kieffer-Olsen <dstdba@post4.tele.dk>
(7) BRITISH SPACE POLICY ON ROUTE TO THIRD WORLD STATUS?
Michael Martin-Smith <martin@miff.demon.co.uk>
(8) AND FINALLY: COMPUTER MODEL BLAMES GREENHOUSE GASES FOR
GLOBAL WARMING
Andrew Yee <ayee@nova.astro.utoronto.ca>
==========
(1) 2000 NM: TEACHER'S TYPO POINTS HIM TO AN ASTEROID
From The Boston Globe, 15 July 2000
http://www.boston.com/dailyglobe2/197/metro/Astronomical_findP.shtml
Astronomical find
Teacher's typo points him to an asteroid
By David L. Chandler, Globe Staff, 7/15/2000
Talk about a lucky mistake.
Earlier this month, as Fitchburg schoolteacher Leonard Amburgey
was
using his backyard observatory, controlled from a computer in his
house, he was carrying on a conversation with friends outside
through
an open window. The distraction caused him to mistype one of the
numbers
to aim his telescope at a specific point in the sky.
Because of that error, what he saw through the scope was not what
he
expected. The streak of light that appeared in that patch of sky
turned
out to be an asteroid on a path that sometimes takes it across
the
Earth's orbit, making Amburgey the first person in Massachusetts
to
discover a near-Earth asteroid.
"I feel very lucky about it," Amburgey said yesterday.
"It was a
pretty good nugget. I was quite astounded."
He is also one of the few amateur astronomers ever to make such a
discovery. Most such finds are now made by one of a handful of
large,
constant professional surveys aimed specifically at protecting
the
Earth by discovering objects that might someday be on a collision
course.
Amburgey's asteroid, called 2000 NM, is not a threat; its orbit
will
keep it safely away from Earth for at least the next million
years,
according to Brian Marsden, the Cambridge-based astronomer who
runs the
official world clearinghouse for information on new astronomical
finds.
But the fact that 2000 NM was found accidentally by an amateur
with a
relatively small telescope underscores the crucial role that
amateurs
still play in the field of astronomy - not to mention acting as
cosmic
lookouts for our planet. Someday, such a discovery could help to
save
the Earth from being blindsided by a hurtling space rock similar
to the
one that is thought to have destroyed the dinosaurs.
But Amburgey, who teaches astronomy and environmental science at
Leominster High School and a graduate course to science teachers
at
Fitchburg State College, wasn't out to make any discoveries.
Rather, he
has been spending every available clear night for the last five
years
observing asteroids, helping with the unglamorous but crucial
work of
doing follow-up observations of asteroids discovered by others.
"My objective is not discovery," Amburgey said. Those
who concentrate
on trying to discover asteroids, comets or supernovas, as many
amateurs
do, end up spending most of their nights taking dozens of
pictures that
then are thrown away because they produce no new finds, he said.
"If I've done 15 or 20 measurements" in a night,
"they're all useful,
they go into the database. If something unique happens - like
discovering an asteroid - that's icing on the cake." That
has happened
twice before, in 1997, when he found two ''main belt"
asteroids - the
relatively commonplace kind.
But the new find is different. "Something like this is more
than just
icing," he added. Near-Earth asteroids are special not only
because
they are much rarer - fewer than 600 are known, compared to more
than
10,000 main belt asteroids, which orbit between Mars and Jupiter.
They
are also of greater interest because they are the only ones that
could
someday threaten human civilization.
Already, Amburgey has received more than 100 congratulatory
e-mail
messages from amateur and professional astronomers.
It is only through the dedicated efforts of amateurs like him in
many
countries, Marsden explained, that the orbits of such asteroids
can be
determined. Without their work, it would be a much more
difficult, if
not impossible, task to determine whether there is a rock out
there
with Earth's name on it. Earth has been pummeled in the past and
someday, astronomers say, there will be another asteroid headed
our
way; it might be tomorrow or a million years from now.
One reason Amburgey was able to find the unusually bright
asteroid when
the pros missed it, Marsden said, was because most of the
professional
search telescopes are concentrated in one area - Arizona and New
Mexico
- that typically receives heavy rain and stormy weather every
July
and August. Local residents refer to it as the monsoon season.
And one
of the few search efforts outside that region, based in Hawaii,
has
been in limited operation lately because of changes being made to
equipment there.
In addition, until late June this particular asteroid was in a
part of
the sky that could only be observed from the Southern Hemisphere,
and
at present there is no ongoing search program for near-Earth
asteroids
south of the equator.
So that left Amburgey and his typing error to make the find, even
though the asteroid was brighter, and thus easier to find, than
most.
Among the string of random events that helped to make the
discovery
possible was the fact that Amburgey was feeling sleepy that
evening,
thanks in part to the early rising time of his 4-year-old twins.
Despite his dedication to backyard astronomy, which he has been
pursuing since 1985, he explains, "I'm not really a night
person."
Details of the asteroid discovery, including the original
pictures, can
be found on Amburgey's Web page:
www.net1plus.com/users/lla/
This story ran on page 1 of the Boston Globe on 7/15/2000.
© Copyright 2000 Globe Newspaper Company.
=================
(2) LINKS TO ASTEROID 2000 NM STORY
From Daniel Fischer <dfischer@astro.uni-bonn.de>
Hi Benny,
regarding the first item, here are a few more links (taken from
http://www.geocities.com/skyweek/mirror/196.html
- sidebar of last story):
http://www.net1plus.com/users/lla/newpage15.htm
- a report from the
discoverer
http://www.regio-info.de/sternwarte-heppenheim/eng/2000nm.htm
- a page
from German asteroid observers on 2000 NM
http://sunkl.asu.cas.cz/~ppravec/2000NM.gif
- a nice light curve.
I have also found an interesting note in the current ESA
AstroNews on
the role the GAIA astrometry mission might play as a NEO hunter:
As it sweeps the sky, GAIA will observe
everything that crosses its sensitive
fields-of- view. Within the
Solar System, GAIA will provide some
spectacular results, since
anything that moves will be noted immediately.
Simulations show
that GAIA might detect up to a million minor
planets, or asteroids.
The brightest Edgeworth-Kuiper Belt objects,
moving around the
Sun beyond the orbit of Neptune, will also be
detectable.
Near-Earth Objects are of significant interest
due to the fact that
they may impact the Earth in the future, with
potentially
catastrophic results, albeit with a very low
probability. The
Barringer Meteor Crater in New Mexico probably
resulted from
the impact of a 40m diameter object, while
object which is believed
to have ended the Cretaceous period probably
had a diameter of
about 10km. By April 2000, the Minor Planet
Centre had recorded
75 Atens class objects, 455 Apollos, 442
Amors, and 37 Centaurs
(these classes reflecting their orbital
characteristics). Many objects
so far undetected with sizes from tens of
metres up to 1km will be
detected and measured by GAIA.
http://astro.estec.esa.nl/SA-general/Astronews/AN-41/an41.html#gaia
Regards,
Daniel
=================
(3) GUYRA METEORITE
From Colin Keay <phcslk@cc.newcastle.edu.au>
Hello Benny:
Your 075/2000 CCNet note about a "Meteor Impact Jars Sleepy
Australian Town" was rather poignant for me. This event was
the
subject of what looks like being my last astronomy article in our
local Newcastle Herald. The last in 34 unbroken years of writing
on
space and astronomy for that newspaper. A new editor is flexing
his
control - axing astronomy but keeping astrology (of course!).
Anyway, no use crying about it. Here is the article as it
appeared on
Saturday, July 8:
--------------------------------------------------------------
SKY AND SPACE NOTES -
8 JULY 2000
by Dr Colin Keay, Astronomer, University of Newcastle
The other day an officer from a Shire Council in the Upper Hunter
phoned to ask advice on the Guyra meteorite. Remember? That's the
object that fell into a water supply dam earlier in the year and
tunnelled into the muddy bottom. A council employee inspecting
the
dam was attracted by the sight of flattened reeds by the edge of
the
water and a disturbance around a hole in the mud about three
quarters
of a metre below the surface.
On the previous night a number of people nearby had been awakened
by
noises said to have followed the appearance of a very bright
meteor
fireball. Police divers were called in and searched the bottom of
the
small lake formed by the dam. Their probe encountered a hard
object
about the size of a cricket ball at the bottom of the hole. They
could not retrieve the object. A resident in the district has
approached Council with an offer to fund the recovery of the
object.
With commendable caution Council has sought expert advice. They
have
had no shortage of advice from a number of quarters, many of whom
have expressed a desire to acquire at least a portion of the
object.
The information supplied to me was somewhat equivocal. The object
could turn out to be a meteorite, but the circumstances have me
wondering. Two aspects set alarm bells ringing in my sceptical
mind.
In the first place meteorites the size of cricket balls have
generally been decelerated to terminal (free-fall) velocity high
up
in the atmosphere. They are not crater-forming and are almost
invariably found lying on the surface of the ground. It is highly
doubtful that one could punch its way through nearly a metre of
water
and retain enough energy to drill through another metre of mud
firm
enough to leave a tell-tale hole.
Then there is the declaration that the flattened reeds showed
signs
of scorching. That particular claim is frequently made about
meteorite falls. Even an assertion that a meteorite was "too
hot to
handle" immediately after a fall is highly suspect in the
case of any
meteorite smaller than a car, or least the size of a basketball.
A parent meteoroid wandering around the solar system in the
vicinity
of the Earth's orbit will acquire a temperature well below
freezing,
in equilibrium between the heat from the Sun on one side and heat
radiation into the chill of space from all sides. Then, during
entry
into the Earth's atmosphere its surface becomes heated to
incandescence and much of the material is ablated away as vapour.
This phase lasts only a matter of a few tens of seconds, not long
enough for the heat to travel right into the core of the
unvaporised
meteoroid.
The heating phase ends when the meteoroid is decelerated to
free-fall
velocity. It then passes through the stratosphere where, as every
jet
traveller knows, the temperature is around minus fifty or sixty
degrees. Therefore cooling from both within and without quickly
quenches any remaining heat. So much so that the more credible
reports of a very recent meteorite fall include a remark about
frost
forming on its surface! So bang goes another urban myth. And I
advised the council officer to seek further guidance from the
Australia Museum in Sydney, rather than local hopefuls.
----------------------
Well that's it Benny. Thank you for your greatly appreciated
newsletter. I hope to meet you in Manchester next month.
Cheers ..... Colin Keay.
================
(4) BLEAK OUTLOOK FOR UK ASTRONOMY:
MORE OBSERVATORIES TO BE CLOSED
From The Sunday Times, 16 July 2000
Astronomers face loss of Jodrell Bank
Jonathan Leake, Science Editor
ASTRONOMERS have been warned
that Jodrell Bank observatory faces
closure and many of them are
threatened with redundancy in a big
cost-cutting exercise.
The observatory, set up in the 1940s,
has laid the foundations for some of the
most important astronomical research of
the century, including the discovery of
quasars - distant galaxies that emit huge
amounts of radiation because they are
being sucked into black holes.
Last week Professor Ian Halliday, chief executive of the Particle
Physics and Astronomy Research Council (PPARC), which funds
Jodrell Bank, said the observatory was likely to face a similar
fate.
He and other leading astronomers believe the future of British
astronomy lies in collaborative projects with other European
countries. However, years of government cutbacks mean the
PPARC cannot fund such international schemes without cutting
British facilities - such as Jodrell Bank, 20 miles south of
Manchester.
Halliday bitterly regrets the loss of domestic facilities.
"We pay
about £14m a year to British universities for research and it is
clear
we are going to have to lose some astronomers," he said.
Halliday wants Britain to use the money saved to join the
European Southern Observatory, a consortium of eight countries
including France, Germany and Italy, which has just finished
assembling a complex of state-of-the-art telescopes on mountain
tops in Chile. The move would place Britain at the forefront of
international research - but with its domestic facilities
severely cut.
Jodrell Bank was founded in 1945 by Bernard Lovell to study
cosmic rays - a phenomenon he had first observed while working
on radar during the second world war.
Over the next few years Lovell built a series of radio telescopes
able to peer ever further and more accurately into space -
leading
the world in radio astronomy for more than 20 years.
The proposals to close Jodrell Bank have shocked eminent
astronomers. Patrick Moore, who presents the BBC's The Sky at
Night, has worked with Jodrell Bank for decades. He said:
"These
bureaucrats have gone crazy. Britain needs its own astronomy
facilities to train new scientists. Jodrell Bank is also still
doing
world-class research - it would be a tragedy to lose it."
Next month hundreds of the world's top astronomers will gather
for the International Astronomical Union's triennial meeting in
Manchester. There they will hear of the latest breakthroughs made
by the radio telescope.
A team led by Peter Wilkinson, professor of radio astronomy at
Manchester University, which runs Jodrell Bank in collaboration
with the PPARC, will announce new evidence confirming that the
universe is expanding at an ever-faster rate.
Nigel Weiss, professor of mathematical astrophysics at Cambridge
University and president of the Royal Astronomical Society, said
any threat to Jodrell Bank would be "foolish".
Last month he chaired a stormy private meeting of the country's
top astronomers to discuss Halliday's proposals. The scientists
accepted Halliday's view that Britain could not afford the next
generation of telescopes on its own - but insisted that Jodrell
Bank
and other facilities must be saved.
Weiss said: "We have to find £60m in capital and £12m a
year
thereafter to join the European Southern Observatory. There will
have to be cuts but it would be foolish to axe Jodrell Bank when
it
is leading some of the world's most exciting developments in
radio
astronomy."
Copyright 2000, The Times Newspapers Ltd.
=============================
* LETTERS TO THE MODERATOR *
=============================
(5) WHY NEOS ARE BOUND TO BE MISSED IN JULY & AUGUST
From David Tholen <tholen@IfA.Hawaii.Edu>
> However, they are concerned that it was found by accident
and was
> missed by the half dozen professional minor-planet surveys
currently in
> operation.
I don't understand the concern. It's "monsoon season"
in the southwest
U.S., where LINEAR, LONEOS, Spacewatch, and the Catalina Sky
Survey all
operate, and NEAT only recently came back on line. If there is a
time
of year when objects are most likely to go unnoticed by the
professional minor-planet surveys, it's July and August. By
locating
most of these surveys in the southwest, we've put too many eggs
in one
basket. Objects are bound to be missed in those months when the
weather
will cut way down on sky coverage.
--Dave
===================
(6) TORINO SCALE HAS A CREDIBILITY PROBLEM
From Jens Kieffer-Olsen <dstdba@post4.tele.dk>
Jonathan Tate <fr77@dial.pipex.com>
wrote:
> There is obviously no ideal translation of this
multidimensional
> problem into a simple one (or two) dimensional system.
This, I believe, is a defeatist attitude, since I remain
convinced that
a scale to measure at some point in time the perceived risk of a
celestial impact must serve primarily as a vehicle to extract
funding
from politicians. Hence the scale should produce a
one-dimensional
figure, namely the amount of $$$ to be allocated immediately, or
over
a specific period.
As the threat is re-assessed ( perhaps as the result of
observations
made possible from such extra funding ) further spending may no
longer
be required, but that of course does not render the original
alarm a
false one. Ideally the scale should dynamically adjust its
cost-algorithm to take into account developments in space
technology.
Attempting to promote the Torino Scale as scientific, necessarily
runs
into the problem of low credibility. Everyone knows that an
announced
risk of impact will soon revert to a measure of zero, so the
shrewd
commentator will position him- or herself with that expectation
in
mind. And hence the 'giggle factor' will remain a certain
companion.
--
Jens Kieffer-Olsen, M.Sc.(Elec.Eng.)
Slagelse, Denmark
===================
(7) BRITISH SPACE POLICY ON ROUTE TO THIRD WORLD STATUS?
From Michael Martin-Smith <martin@miff.demon.co.uk>
From BBC News, 13 July 2000:
>It says: "Any decline in the number and calibre of
science and
>technology graduates raises problems far beyond those of the
space
>industry alone. "A small industry such as space is
particularly
>vulnerable.
>
>"The next UK space strategy must explicitly address the
question of the
>supply of appropriately qualified graduates so that the space
industry
>can be sustained in the years ahead."
I have always maintained that space exploration and development
can
inter alia be justified economically on the grounds that it
fosters and
encourages the uptake of science studies by students - many of
whom may
not necessarily "go to the Moon", but who will make
valuable
contributions to a science-based society. Our prosperity and
ability to
manage global resources and environment in the Human interest
will for
the forseeable future be utterly dependent of healthy science and
technology, including, to an extent, space technology.
We should compare the difference in wealth and capability we
enjoy
with that of a society innocent of science and exploration - for
example that of pre-Tudor England. This contrast affords a useful
measure of the longterm economic value of the science,
technology, and
above all exploration carried out over 5 centuries by the peoples
of
Western Europe.
It looks as if slow abandonment of space activity is a royal
route to
poor competitiveness, third world status - and worse. China and
India
are both explicitly and deliberately pursuing ambitions in Space,
for
among other reasons, the ones I cite. If Life is a game, he who
does
not will to win, deserves to lose!
--
Michael Martin-Smith
=============
(8) AND FINALLY: COMPUTER MODEL BLAMES GREENHOUSE GASES FOR
GLOBAL WARMING
From Andrew Yee <ayee@nova.astro.utoronto.ca>
Texas A&M University
Contact:
Judith M. White, 979-845-6746, jw@univrel.tamu.edu
Dr. Thomas Crowley, 979-845-0795
7/14/00
Greenhouse Gases Responsible For Global Warming Since 1850, Texas
A&M
Study Suggests
COLLEGE STATION -- If you think summers are more scorching than
when
you were a kid, you're right. Research at Texas A&M
University supports
the notion that Earth is getting hotter.
"Global warming is a reality," said Thomas Crowley, a
geoscientist who
specializes in climate modeling. "It's already here."
Crowley constructed a computer model to examine the sharp
temperature
increases registered at the end of the 20th century. The model
provides
further evidence that the increasing rate of temperature climb
stems
from the accumulation of greenhouse gases in the Earth's
atmosphere.
Crowley's climate simulation was published in the July 14 issue
of
Science, the prestigious journal of the American Association for
the
Advancement of Science (AAAS). Scientists agree that Earth's
climate
over the past millenium has had its share of ups and downs, but
according to this new model, it takes an unprecedented change,
such as
a boost in greenhouse gas emissions, to explain the past
century's
unusual warming trends.
Crowley's research also predicts that by the year 2100,
temperatures in
Earth's northern hemisphere will have risen 1.5 degrees
Centigrade, for
a total increase of about 2.5 degrees Centigrade -- close to 5
degrees
Fahrenheit -- since the beginning of the Industrial Revolution.
"These may seem like small increases, but they have
potentially big
consequences," Crowley noted. Because temperature increases
are
expressed as mean annual temperature change, with daily
temperatures
averaged over the entire year, figures do not reflect the greater
changes that may occur in the summer months, for example. And
rising
temperatures can result in shrinking glaciers, rising sea levels,
and,
possibly, severe weather.
"To illustrate, the Dust Bowl of the 1930s reflected a
temperature
change of a fraction of the amount projected by the new
model," said
Crowley, professor of oceanography in Texas A&M's College of
Geosciences. "And both the 1930's heat wave and the 1950's
drought that
swept Texas resulted from only a 1 degree Centigrade change in
mean
annual temperature."
For decades, scientists have debated the existence of global
warming
and the reality of the greenhouse effect. Over the past 1,000
years,
the Earth has experienced alternating cycles of relatively cooler
and
warmer temperatures, Crowley observed. Natural rhythms of the
oceans
and atmosphere contribute to these cycles, as do changes in
volcanic
activity and periodic fluctuations in the amount of radiation
received
from the sun.
"Taken together, natural causes and so-called 'forcing
events' like
sunspot flares and volcanic eruptions can account for about 41 to
64
percent of the Earth's temperature changes between 1000 and
1850,"
Crowley said. "Such factors cannot explain the unusual
warming trend of
the late 20th century, however."
Crowley's model, on the other hand, adds anthropogenic, or
man-made,
factors to the forces of nature and produces correlations
explaining
far more of the temperature variations over the same period.
"My basic strategy was to seek added insight into the late
20th century
warming trend by interpreting it within the context of how well
we
understand climate change over the entire last millennium,"
Crowley
said. His model explains more of the total temperature variance
because
it takes into account such a long period of time, with
correspondingly
more observations. Crowley focused on records from the Northern
Hemisphere. He was assisted with graphics for this study by
Thomas S.
Lowery, an undergraduate at Texas A&M. The two also are
co-authors of a
paper on temperature increases during the Middle Ages, which was
published by the Royal Swedish Academy of Sciences, the group
that
awards the Nobel Prizes.
Scientists determine past temperatures by examining natural
records --
such as tree rings and ice cores -- from different sites, then
correlating results. Since 1860, recorded temperature
observations also
have been available for the Northern Hemisphere, and scientists
have
been able to compare this data with that obtained from natural
sources
to yield a composite temperature record.
"During the last 25 years, temperatures have been far warmer
than
expected. This represents a very, very unusual warming trend,
which is
supported by the weight of recently collected evidence,"
Crowley said.
"Although there are still uncertainties, in a sense the
glass is now 80
percent full.
The late 20th century temperature increase is best explained by
the
accumulation of greenhouse gases in the atmosphere," he
observed. "If
we remove all the forcing effects and look at what's left, the
curve
generated by greenhouse gas emissions agrees closely with the
curve
showing temperature increases."
Greenhouse gases -- primarily carbon dioxide -- are so-called
because
they trap re-radiation of solar heat from the Earth's surface in
the
atmosphere close to the Earth. As the atmosphere warms, it can
hold
more water vapor, which in turn traps more heat, causing a chain
reaction.
Although greenhouse gases occur naturally in the atmosphere,
their
concentration has increased dramatically since 1850 due to
burning of
fossil fuels and deforestation. It is easier to determine the
effects
of volcanism and solar variability prior to 1850, before the
man-induced changes came into play. For example, during the
Little Ice
Age that occurred in the 17th and 18th centuries, the Earth was
colder
than usual. Alpine glaciers extended farther down Swiss valleys
than
today, and parts of New England referred to years without summer,
with
snow falling in New Hampshire in July 1816.
"The amount of carbon dioxide in the atmosphere today is at
its highest
level in the last 400,000 years of history," Crowley
observed.
"It's sobering that we have used only 5 percent of the total
amount of
fossil fuel available. That's the tip of the iceberg; by the year
2100,
we will have still used only 30 to 35 percent of our fossil fuel
reservoir," he added. "And carbon dioxide released from
burning fossil
fuels stays in the atmosphere for 100 years or more."
-----------
MODERATORS NOTE: For a critical assessment of such and
other computer models
see: John L. Daly: The Surface Record: Global Mean Temperature
and How it is
Determined at Surface Level at
http://www.greeningearthsociety.org/Articles/2000/surface1.htm
----------------------------------------
THE CAMBRIDGE-CONFERENCE NETWORK (CCNet)
----------------------------------------
The CCNet is a scholarly electronic network. To
subscribe/unsubscribe,
please contact the moderator Benny J Peiser <b.j.peiser@livjm.ac.uk>.
Information circulated on this network is for scholarly and
educational use only. The attached information may not be copied
or
reproduced for any other purposes without prior permission of the
copyright holders. The fully indexed archive of the CCNet, from
February 1997 on, can be found at http://abob.libs.uga.edu/bobk/cccmenu.html