PLEASE NOTE:
*
CCNet CLIMATE SCARES & CLIMATE CHANGE, 29 March 2001
----------------------------------------------------
"Spend a little time in Europe, and you start to feel
nothing is
safe. Over here, cellphones cause brain damage and T-bone steaks
are
lethal. Flying economy class gives you blood clots. Even that
plastic toy
bobbing in the bathtub is toxic. At least that is what Europeans
are told.
These days, hardly a week goes by without another health scare
sweeping
the continent. Never mind that many of the warnings are absurd,
or based on
flimsy science. Europeans are now so jittery, so convinced that
modern life is a minefield, that the merest whiff of risk sends
them
scurrying for cover. Even as incomes rise and lifespans lengthen,
the
continent is gripped by a wave of Euro-fear, a shared continental
cringe.
"Europe has lost its nerve," says Frank Furedi, a
sociologist at
Britain's University of Kent and an expert on the new malaise.
"Every
problem today, however small, is represented as a major
disaster."
--Carl Honoré, National Post, 22 March 2001
"Professor Martin Parry, a leading climatologist and
lecturer at the
University of East Anglia, said: "We are entering what we
expect to be
a phase of increased global warming where the likelihood of
warmer
summers increases." The Met Office said that predictions
could be
made only up to five days in advance with any accuracy. A
spokesman said:
"We would love to be able to forecast far ahead, but you
cannot. The
weather is based on chaos theory and it does not know what it is
going
to do in three or six months."
--The Daily Telegraph, 27 March 2001
"Rebounding from the weight of ice sheets that depressed the
land
during the ice age, Scandinavia has risen more than a half-mile
in the
past 20,000 years, according to new satellite measurements. In a
study
appearing Friday in the journal Science, researchers report that
Sweden,
Norway, Finland and Denmark are moving upward at almost a half an
inch year
as a rebound from the melting of two-mile-thick ice
mountains."
--Paul Recer, AP, 23 March 2001
"Despite claims from environmentalists committed to global
warming
catastrophe scenarios and the politicized scientists who run the
IPCC, it
is clear that the science of global warming is far from settled.
As Carl
Sagan once said (but didn't practice), "Extraordinary claims
require
extraordinary evidence."
--Ronald Bailey, science editor, Reason Magazine, 21 March
2001
(1) ANCIENT TREE RINGS GIVE CLIMATE CLUES
BBC News Online, 28 March 2001
(2) ARCTIC SUBMARINE UNCOVERS EVIDENCE OF GIANT, ANCIENT ICE
SHEETS
Andrew Yee <ayee@nova.astro.utoronto.ca>
(3) NEW POLAR TEMPERATURE DATA
Greening Earth Society, 14 March 2001
(4) COOLING EASTERN MEDITERRANEAN TEMPERATURES
Greening Earth Society, 26 March 2001
(5) RADARSAT-1 HELPING SCIENTISTS MEASURE GLOBAL CLIMATE CHANGE
IN
ANTARCTICA
Andrew Yee <ayee@nova.astro.utoronto.ca>
(6) GLOBAL WARMING LEADS TO RECOVERY FROM ICE AGE
Excite News, 23 March 2001
(7) CLIMATE MODEL INADEQUACIES: THE INFLUENCE OF CLOUDS
CO2 Science Magazine, 28 March 2001
(8) EVIDENCE FOR LITTLE ICE AGE DOWN UNDER
CO2 Science Magazine, 28 March 2001
(9) "LITTLE ICE AGE" RESEARCH: A PERSPECTIVE FROM
ICELAND
Ogilvie AEJ, Jonsson T
(10) COMMENT ON THE "CCNet SPECIAL: COMETARY IMPACTS AND
ICE-AGES"
Dewey McLean <dmclean@vt.edu>
(11) AND FINALLY: EUROPE IS FREAKING OUT
National Post, 22 March 2001
===========
(1) ANCIENT TREE RINGS GIVE CLIMATE CLUES
From BBC News Online, 28 March 2001
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1247000/1247636.stm
By BBC News Online's Ivan Noble
Ancient tree stumps uncovered in a South American earthquake have
provided
the most detailed picture yet of the world's climate before the
last ice
age.
An international team looked at the seasonal growth rings in 28
examples of
Fitzroya cupressoides, a conifer from the region.
They found what seems to be early evidence of El Niño, the
largest single
source of modern weather variation, which is caused by a cyclical
movement
of warm waters in the Pacific.
The researchers say the trees, from Pelluco in southern Chile,
provide an
unprecedented weather record from 50,000 years ago.
"What it has done is give us a first glimpse of year-by-year
records,"
explained Dr Keith Briffa of the University of East Anglia, UK.
'Lottery win'
The scientists were able to study the trees as a result of two
natural
disasters.
The first covered up and preserved the trees around 500 centuries
ago. The
second, in 1960, began to bring the trees back to the surface.
"It is a bit like a lottery win," Dr Briffa told BBC
News Online. "There was
a bit of tectonic movement in 1960 which allowed erosion to
expose the
remains."
Dr Briffa is co-author of a study of the trees, which is
published in the
journal Nature.
He helped analyse the data collected from the ancient specimens,
and put
together information from separate trees to make one single
1,229-year
climate record.
Bigger picture
"It is probably the oldest ever, continuous, annually
resolved chronology,"
he said.
By studying the annual growth spurts, dendrochronologists can get
an idea of
the seasonal conditions that existed year on year through a
tree's life -
how warm it might have been, the amount of moisture that might
have been in
the soil, etc.
Well-preserved or subfossil trees have been found before in
Tasmania and
Siberia, but they were around 10,000 years old - much younger
than the
Chilean samples.
The data will be more significant once they can be linked to
other evidence
of ancient climate variation - what scientists refer to as proxy
data.
"At present, most of our information is from oxygen isotopes
in ice cores in
Greenland and studies have been done tying this in with ocean
sediments," Dr
Briffa added.
These data allow researchers to build a picture of what the
Earth's climate
was like before humans were around to make written records.
Copyright 2001, BBC
==========
(2) ARCTIC SUBMARINE UNCOVERS EVIDENCE OF GIANT, ANCIENT ICE
SHEETS
From Andrew Yee <ayee@nova.astro.utoronto.ca>
Ohio State University
Contact:
Leonid Polyak, (614) 292-2602; Polyak.1@osu.edu
Written by Pam Frost Gorder, (614) 292-9475; Gorder.1@osu.edu
Editor's note: This release is embargoed until 2:00 p.m. EST on
March 21,
2001, to coincide with publication in the March 22 issue of the
journal
Nature.
ARCTIC SUBMARINE UNCOVERS EVIDENCE OF GIANT, ANCIENT ICE SHEETS
COLUMBUS, Ohio -- A scientific expedition on a submarine in the
Arctic has
found the footprints of ancient floating ice sheets -- possibly
the largest
masses of ice ever to cover the earth's oceans.
Studying the formation and demise of these ancient ice sheets may
help
scientists better understand Earth's climate changes and, in
particular,
predict whether the melting of today's polar ice could lead to
catastrophic
floods in the future.
Leonid Polyak, research scientist at Byrd Polar Research Center
at Ohio
State, and his colleagues obtained sonar images of the Arctic
Ocean floor
through a unique collaboration between the U.S. Navy and civilian
scientists
-- the Science Ice Exercises (SCICEX) program.
The results appear in the March 22 issue of the journal Nature.
Polyak's
collaborators, Margo Edwards of the University of Hawaii and
Bernard Coakley
of Tulane University, were chief scientists on the 1999 SCICEX
mission,
which took place aboard the nuclear submarine USS Hawkbill.
Within two separate, somewhat elevated regions of the Arctic
Ocean floor --
the Lomonosov Ridge near the North Pole and the Chukchi
Borderland near
Alaska -- SCICEX images showed numerous features carved into the
seafloor,
including matching sets of parallel grooves and ridges. Sometime
in the
past, Polyak said, the bottom of a very massive floating ice
sheet scraped
across the seafloor in both areas -- almost 1 km below the water
surface at
the Lomonosov Ridge and more than 700 meters below the water
surface at the
Chukchi Borderland.
The sonar images clearly showed objects resembling rocks and
other debris
that may have once been dragged along the seafloor beneath the
grounded ice.
"The results were just fantastic. We had hoped to find these
seafloor
features, but we hadn't expected to get such beautiful
images," Polyak said.
"Such amazingly coherent sets of streamlined grooves and
ridges could only
be made by one thing -- sliding ice," Polyak continued. And
only a large ice
sheet could carve such a broad sets of parallel features.
Free-floating
icebergs, he explained, carve random patterns into the seafloor.
The finding may bolster a theory held by some scientists: that
one giant ice
sheet covered the entire Arctic periodically during the ice ages
that
occurred between 10,000 and 1.5 million years ago.
But Polyak thinks that the same features might have been carved
by several
large ice sheets instead of one. To find out for sure, he and his
colleagues
must determine whether the features formed at the same time in
different
regions of the Arctic Ocean. That's why the researchers have
applied for
funding to return to the Arctic on an icebreaker to take core
samples from
the seafloor.
"Even if there were two or more ice sheets instead of one,
they were still
giant structures of several hundred kilometers in length --
comparable to
vast floating ice sheets observed today around Antarctica,"
said Polyak.
The researchers sought evidence of the ancient floating ice
sheets in part
to gather clues about the future of the West Antarctic Ice Sheet.
Unlike the ice in East Antarctica, the ice in West Antarctica is
considered
unstable because a large portion of it is floating. For years,
scientists
have debated whether a warming of earth's climate would cause the
ice sheet
in West Antarctica to collapse, which would cause sea levels to
rise fast,
possibly as high as 20 feet all over the world.
Polyak, a former biologist, says these findings also hold
implications for
other areas of science. For instance, he wonders how prehistoric
life in the
Arctic Ocean could have survived if the entire area was covered
with an ice
cap of several hundred meters in thickness.
This question is related to a recently proposed theory called
"snowball
Earth," Polyak said. The theory holds that ice completely
covered the
Earth's oceans at some time between 550 and 750 million years
ago,
drastically affecting the evolution of primitive life.
"Who knows -- maybe clarifying the history of floating ice
sheets in the
Arctic Ocean will even help us understand the evolution of
ice-bound
planets, such as Jupiter's moon Europa," he said.
[Editor's note: Polyak will be out of the office March 20-22, but
will be
reachable by telephone and e-mail during that time. To reach him
by
telephone on those days, please contact Pam Frost Gorder at (614)
292-9475.]
========
(3) NEW POLAR TEMPERATURE DATA
From the Greening Earth Society, 14 March 2001
http://www.greeningearthsociety.org/Articles/2001/vca9.htm
Updated surface and weather-balloon measured temperature
histories from
National Oceanic and Atmospheric Administration (NOAA) scientist
Jim Angell
thumped into our Inbox, this week. Angell's surface and
above-surface
temperatures are well regarded by climatologists. Each weather
balloon
ascent begins at ground level, where temperature is measured by
the
highly-calibrated onboard instruments and first logged.
Much has been made of polar temperatures recently. Recall the
noisy
headliner in last summer's New York Times about the disappearance
of the ice
cap at the North Pole, and how it was quietly retracted three
weeks later?
You'll also recall hearing about Delaware-sized chunks of
Antarctica
breaking off. The "larger question" about melting polar
ice is this: Is it
caused by human-induced climate change?
Unnecessary as it may seem, let's first stipulate that polar ice
does not
melt in the winter. This is important. Winter is the time of the
year that
would or should show the largest warming if the climate models
are right.
Polar ice does not melt in winter/polar night because it's just
too darned
cold at somewhere between -25 and -40°C on an average winter day
in the
Arctic and Antarctic, respectively.
Good fishermen know you're more likely to succeed if you fish
where the fish
are. So it is with polar climatology; ice fish where the ice fish
are. If
you're looking for melting of polar ice, the summer should prove
more
fruitful than winter. To that end, our figures below show winter
(DJF in the
North, JJA in the South) juxtaposed with summer temperatures for
each polar
region. Angell defines these as poleward of 60° latitude for
each
hemisphere.
It may come as a surprise how much data has been amassed from
these remote
wildernesses. That's because of two things: The Cold War (source
of info on
the north polar region) and the International Geophysical Year
(1957) when
international scientific cooperation resulted in much of the
Antarctic
perimeter becoming peppered with permanent weather stations.
Figure 1 (http://www.greeningearthsociety.org/Articles/2001/vca9.htm)
shows
winter and summer temperature trends in the Arctic beginning in
1958. There
is no trend line in the summer data because, in fact, there's no
significant
trend in warming over the 43-year record. On the other hand,
winters are
warming significantly, at the rate of 2.6°C/100 years.
North of 60°N is what climatologists call a "source
region" for the frigid,
deadly airmasses that impolitely and routinely barrel
equator-ward and are
given names like "The Siberian Express." This zone is
warming up, in winter.
But Arctic summer shows no significant change. That means Arctic
climate is
not changing in a fashion that is likely to melt things very
much. This is
not to say there will be no trend forever. At the current rate of
change, a
statistically significant warming should emerge in the summer
Arctic
somewhere around the year 2020.
Things are quite similar in the South Polar regions (Figure 2),
in which
there also is a statistically significant warming of the winter
(3.7°C/100
years) and where there is no trend yet evident in Antarctic
summer. How then
to explain those Delaware-sized icebergs? Stay tune.
=========
(4) COOLING EASTERN MEDITERRANEAN TEMPERATURES
From Greening Earth Society, 26 March 2001
http://www.greeningearthsociety.org/Articles/2001/cool.htm
By Robert C. Balling, Jr., Ph.D.
Greening Earth Society Science Advisor
Cairo University's Dr. H.M. Hasanean summarizes his analysis of
eastern
Mediterranean temperature trends in a recent edition of
Theoretical and
Applied Climatology writing, "During the period under study,
a temperature
decrease is observed."
Hasanean's article, "Fluctuations of Surface Air Temperature
in the Eastern
Mediterranean" concerns temperature records collected from
eight major
cities in the eastern Mediterranean. The sites include Malta,
Athens,
Tripoli, Alexandria, Amman, Beirut, Jerusalem, and Lattakia. The
records'
time spans begin anywhere between 1853 and 1952, depending upon
the site,
and extend through 1991.
Four of the stations had positive trends that indicate warming.
The other
four had negative trends, indicating cooling. These are some of
the largest
cities in that region and, surely, their temperature records that
suffer a
bias imposed by urban heat island effects. Nonetheless, Dr.
Hasanean failed
to find any warming during the recent decades - the period of
time when
greenhouse gas concentrations have most dramatically increased
due to human
industrial activity.
If one downloads temperature data available from the United
Nations
Intergovernmental Panel on Climate Change (IPCC) for this same
region - data
that includes rural areas as well as sea-surface temperatures in
the eastern
Mediterranean - the data are presented as monthly temperature
anomalies
(departures from normal) for the twelve 5° latitude by 5°
longitude grid
boxes that encompass the eastern Mediterranean region. The IPCC
data spans
1920 to 1991 and therefore overlaps most of the data Hasanean
used. Figure 1
presents that eastern Mediterranean near-surface air temperature
record and
shows a cooling of 0.18°C (0.32°F).
Here we have it, once again. Important research work fully in
agreement with
available IPCC data receives zero publicity from a worldwide and
European
press inflamed by the potential for catastrophic global warming.
If
Hasanean's work stoked that engine, the situation no doubt would
be
different.
Reference:
Hasanean, H.M., 2001: Fluctuations of surface air temperature in
the Eastern
Mediterranean. Theoretical and Applied Climatology, 68:75-87.
==========
(5) RADARSAT-1 HELPING SCIENTISTS MEASURE GLOBAL CLIMATE CHANGE
IN
ANTARCTICA
From Andrew Yee <ayee@nova.astro.utoronto.ca>
Canadian Space Agency
Canada's RADARSAT-1 Helping Scientists Measure Global Climate
Change in
Antarctica
Saint-Hubert, Quebec, March 21, 2001 -- Images produced by
RADARSAT-1,
Canada's renowned Earth Observation satellite is helping a team
of
scientists answer crucial questions about the rate and extent of
global
climate change in Antarctica. This initiative, the second since
1997, was a
joint project of the Canadian Space Agency and NASA.
Early analyses show that in just three years the Amery Ice Shelf
has
advanced five kilometres, while the Shirase Glacier, located in
the Indian
Ocean sector of the continent, has retreated twelve kilometres.
Scientists
are seeking to understand whether this variability is due to the
forces of
external climate on the great ice sheet or due to natural and
episodic
instabilities that arise from the forces that control complex
glacier flow.
The new velocity measurements from this second completed mission
will help
answer these questions.
"The Antarctic Ice Sheet moves slowly and surely under the
force of its own
enormous weight," says Principal Scientist Dr. Kenneth C.
Jezek of The Ohio
State University's Byrd Polar Research Center. "This mission
gives us the
first, overall snapshot of how the ice moves and important new
insight into
how and why the ice sheet is changing. Moreover, by measuring the
extent and
velocity of the moving ice and estimating its thickness, we can
estimate how
much ice may be lost into the ocean from Earth's largest
storehouse of
freshwater. These calculations are important for understanding
Antarctica's
contribution to the present rate of sea level rise of about two
millimeters
a year."
For this mission, the Canadian Space Agency's RADARSAT-1
satellite trained
its imaging radar on the outer half of the continent twice during
each of
three consecutive 24-day periods, ending last Nov. 14. "This
was a
challenging mission for our professionals who had to accurately
navigate the
satellite, controlling the 800 kilometre orbit, while
periodically firing
the spacecraft's onboard thrusters so as to position the
satellite within a
few hundred meters of its
nominal track on each orbit," said Rolf Mamen, Director
General of Space
Operations at the Canadian Space Agency. Precise navigation and
data from
the six passes make it possible to create detailed topographic
maps and to
measure the speed of the moving glaciers.
The two scientific missions supported by RADARSAT-1 have produced
a new
baseline dataset for the scientific community -- one that will
prove
invaluable in monitoring the state of the Antarctic ice cap. And
although
RADARSAT-1 is being exploited by the Canadian Space Agency beyond
its
nominal lifetime, this same leading-edge technology continues to
produce
outstanding imagery is also being brought to bear on studies of
polar ice in
Canada's Arctic region.
RADARSAT-2, currently under construction for the Canadian Space
Agency by
MacDonald Dettwiler and Associates of British Columbia and
scheduled for
launch in 2003, will contribute to expanding the vast data
archive already
captured by RADARSAT-1. These unique Earth Observation
spacecraft, and the
team of highly skilled Canadian Space Agency professionals
operating them,
are performing an important service, providing key data for
clients in the
fields of mapping, geology, oceanography, ice surveillance,
agriculture,
natural resources exploration, supporting disaster and relief
efforts
worldwide and helping scientists improve their understanding and
measure the
effects of global warming on our planet Earth.
About the Antarctic Mapping Missions
Building on the success of the first complete mapping of the
continent in
1997, RADARSAT-1 was again deployed in November, 2000 to support
a second
Antarctic Mapping Mission. This follow-on initiative was a joint
project of
the Canadian Space Agency and NASA. The science team includes
members from
the Byrd Polar Research Center at The Ohio State University,
NASA's Jet
Propulsion Laboratory, the Alaska SAR Facility at the University
of Alaska,
Fairbanks, and the Vexcel Corporation. The mission is part of
NASA's Earth
Science Enterprise, a long-term research program dedicated to
studying how
human-induced and natural changes affect our global environment.
About the Canadian Space Agency
Established in 1989 and situated in Saint-Hubert, Quebec, the
Canadian Space
Agency (CSA) coordinates all aspects of the Canadian Space
Program. Through
its Space Knowledge, Applications and Industry Development
business line,
the CSA delivers services involving: Earth
and the Environment; Space Science; Human Presence in Space;
Satellite
Communications; Generic Space Technologies; Space Qualification
Services and
Awareness. The Canadian Space Agency is at the forefront of the
development
and application of space knowledge for the benefit
of Canadians and humanity.
For more information:
B-Roll will be broadcast on NASA TV, March 22 between 16:30-21:00
(GE-2.,
transponder 9C, C-Band, 85 degrees West longitude; frequency
3888.0 MHz,
polarization vertical, audio monaural at 6.8 MHz)
The mission: http://www-bprc.mps.ohio-state.edu/radarsat
The images: http://www.jpl.nasa.gov/pictures/antarctica/
The Canadian Space Agency and RADARSAT-1: http://www.space.gc.ca
André Leclair
Senior Communications Advisor
Canadian Space Agency
(450) 926-4370
andre.leclair@space.gc.ca
=======
(6) GLOBAL WARMING LEADS TO RECOVERY FROM ICE AGE
From Excite News, 23 March 2001
http://news.excite.com/news/ap/010323/02/ice-recovery
By PAUL RECER, AP Science Writer
WASHINGTON (AP) - Rebounding from the weight of ice sheets that
depressed
the land during the ice age, Scandinavia has risen more than a
half-mile in
the past 20,000 years, according to new satellite measurements.
In a study appearing Friday in the journal Science, researchers
report that
Sweden, Norway, Finland and Denmark are moving upward at almost a
half an
inch year as a rebound from the melting of two-mile-thick ice
mountains.
"There is not one place in Scandinavia that was not covered
with ice," said
Jerry X. Mitrovica of the University of Toronto. "The land
was pressed down
about a kilometer (five-eighths of a mile), and when the ice
melted, the
land started going up in a process that continues even
today."
Mitrovica, co-author of the study, said the weight of the ice was
equal to
about 6.6 million pounds per square yard of land surface in
Scandinavia.
Scientists have long known that Scandinavia, Canada and other
places buried
under frozen mountains during the last ice age have been
rebounding. Until
now, however, researchers were not sure how fast the land was
rising.
Mitrovica and his co-authors used data from 33 sensors placed
strategically
around Scandinavia to pick up signals from the Global Positioning
Satellite
system. Combining this data and correcting it for atmospheric
distortion
enabled them to measure the land movement to a scale of about 1
millimeter,
a fraction of an inch, per year.
They found that, on average, the land under the ancient ice
burden is rising
annually by about 9 millimeters. An inch is about 25 millimeters.
Knowing this amount of rise, Mitrovica said, makes it possible
for the first
time to use two centuries of sea level measurements from
Scandinavia.
"The best-kept records for sea level change in the world is
in the
Scandinavian region," said Mitrovica. But scientists have
not been able to
trust the records, because they knew the land rebounding from the
ice age
was affecting sea levels in the area.
For instance, Mitrovica said, the ocean could be rising at 7
millimeters a
year in Scandinavia, but because the land was rising at 9
millimeters a
year, it would appear that sea level was dropping.
"Our study confirms that the sea level in Scandinavia is
doing what others
have seen in other parts of the globe," said Mitrovica.
"This is one of the
important confirmations of sea level rising. Sea level is going
up worldwide
about 2 millimeters a year."
Besides rising, Scandinavia's rebound is also moving
horizontally, he said.
Mitrovica compares this type of expansion to what would happen if
someone
turned over a bowl and stepped on it. While the bowl center is
flattened,
the edges of the bowl move outward. The same thing is happening
in
Scandinavia, he said.
"We measure a horizontal change in the land of 2 to 3
millimeters a year,"
said Mitrovica.
This means that Scandinavia, in its 20,000-year recovery from the
last ice
age, is growing both upward and outward, he said.
Mitrovica said that all the ice from the last ice age is gone
from
Scandinavia, but traces still exist of ancient ice in Canada. The
North
American ice sheet once extended from the Canadian Arctic deep
into the
northern United States.
Copyright 2001, AP
=======
(7) CLIMATE MODEL INADEQUACIES: THE INFLUENCE OF CLOUDS
From CO2 Science Magazine, 28 March 2001
http://www.co2science.org/subject/m/summaries/inadeqclouds.htm
Correctly incorporating the influence of clouds on climate is an
elusive
goal the creators of atmospheric general circulation models
(GCMs) have yet
to achieve. One reason for their lack of success in this endeavor
has to do
with model resolution on both the horizontal and vertical space
scales. Lack
of adequate resolution forces modelers to parameterize the
ensemble
large-scale effects of processes that occur on smaller scales
than those
their models' are capable of handling. Such is the case when it
comes to
representing physical processes such as cloud formation and
cloud-radiation
interactions. The question naturally arises, therefore, as to
whether the
parameterizations used in today's models are adequate for the
treatment of
such processes and their interactions. The results of several
recent studies
seem to suggest they are not (Groisman et al., 2000).
Lane et al. (2000), for example, evaluated the sensitivity of a
suite of
cloud-radiation parameterizations typically found in contemporary
GCMs to
determine the sensitivity of those parameterizations as a
function of
vertical model resolution, varying the resolution from 16 to 60
layers in
increments of four and comparing them to observed values.
The results of
their study showed that simulated values of cloud-radiation
variables were
highly sensitive to changes in vertical resolution. Cloud
fraction varied
by about 10% over the range of resolutions tested, which
corresponded to
about 20% of the observed fraction of cloud cover.
Similarly, outgoing
longwave radiation varied by 10 to 20 Wm-2 as the resolution was
varied,
amounting to around 5 to 10% of the observed value; and incoming
solar
radiation also experienced significant variations across the
range of
resolutions tested. Furthermore, the model results did not
converge, even
at a resolution of 60 layers, and there were significant
systematic
differences between model results and observations.
Grabowski (2000) has also noted some serious problems related to
the extent
to which computer models correctly incorporate cloud
microphysical processes
that influence climate, stating that "it is unlikely that
traditional
convection parameterizations can be used to address this
fundamental
question in an effective way." Indeed, he notes that
"classical convection
parameterizations do not include realistic elements of cloud
physics and
they represent interactions among cloud physics, radiative
processes, and
surface processes within a very limited scope."
Consequently, he states the
obvious when he says that "model results must be treated as
qualitative
rather than quantitative."
In another paper, Gordon et al. (2000) report that many GCMs tend
to
under-predict the presence of subtropical marine stratocumulus
clouds, and
that they fail to predict the seasonal cycle of such
clouds. These
deficiencies are especially important, because marine
stratocumulus clouds
have a major cooling impact on sea surface temperatures below
them.
Further condemnation of state-of-the-art model treatments of
clouds comes
from Harries (2000), who states that our knowledge of high cirrus
clouds is
very poor and that "we could easily have uncertainties of
many tens [our
italics] of Wm-2 in our description of the radiative effect of
such clouds,
and how these properties may change under climate
forcing." Such a view is
particularly noteworthy in light of the fact that the radiative
effect of a
doubling of the air's CO2 content is only on the order of 4
Wm-2. It is,
therefore, truly an understatement to say, as he does, that
"uncertainties
as large as, or larger than, the doubled CO2 forcing could easily
exist in
our modeling of future climate trends, due to uncertainties in
the feedback
processes."
With the appearance of the recent report of Lindzen et al.
(2001), this
assessment appears to have been prophetic. For example,
Lindzen et al.
analyzed cloud cover and sea surface temperature (SST) data over
a large
portion of the Pacific Ocean, finding a strong inverse
relationship between
upper-level cloud area and mean SST, such that the area of cirrus
cloud
coverage normalized by a measure of the area of cumulus coverage
decreases
about 22% per degree Celsius increase in the SST of the cloudy
region.
"Essentially," the authors state, "the
cloudy-moist region appears to act as
an infrared adaptive iris that opens up and closes down the
regions free of
upper-level clouds, which more effectively permit infrared
cooling, in such
a manner as to resist changes in tropical surface
temperature." The
sensitivity of this negative iris feedback was calculated by the
authors to
be substantial. In fact, they say it would "more than
cancel all the
positive feedbacks in the more sensitive current climate
models" that are
used to predict the consequences of projected increases in
atmospheric CO2
concentration. And as one might suppose, this potential
real-world
impediment to global warming is not anywhere manifest in
state-of-the-art
GCMs.
References
Gordon, C.T., Rosati, A. and Gudgel, R. 2000.
Tropical sensitivity of a
coupled model to specified ISCCP low clouds. Journal of
Climate 13:
2239-2260.
Grabowski, W.W. 2000. Cloud microphysics and the
tropical climate:
Cloud-resolving model perspective. Journal of Climate 13:
2306-2322.
Groisman, P.Ya., Bradley, R.S. and Sun, B. 2000. The
relationship of cloud
cover to near-surface temperature and humidity: Comparison of GCM
simulations with empirical data. Journal of Climate 13:
1858-1878.
Harries, J.E. 2000. Physics of the earth's radiative
energy balance.
Contemporary Physics 41: 309-322.
Lane, D.E., Somerville, R.C.J. and Iacobellis, S.F.
2000. Sensitivity of
cloud and radiation parameterizations to changes in vertical
resolution.
Journal of Climate 13: 915-922.
Lindzen, R.S., Chou, M.-D. and Hou, A.Y. 2001. Does
the earth have an
adaptive infrared iris? Bulletin of the American
Meteorological Society 82:
417-432.
Copyright © 2001. Center for the Study of Carbon Dioxide
and Global Change
===========
(8) EVIDENCE FOR LITTLE ICE AGE DOWN UNDER
From CO2 Science Magazine, 28 March 2001
http://www.co2science.org/journal/2001/v4n13c1.htm
Reference
Domack, E., Leventer, A., Dunbar, R., Taylor, F., Brachfeld, S.,
Sjunneskog,
C. and ODP Leg 178 Scientific Party. 2001. Chronology
of the Palmer Deep
site, Antarctic Peninsula: A Holocene palaeoenvironmental
reference for the
circum-Antarctic. The Holocene 11: 1-9.
What was done
Ocean sediment cores were obtained from a prominent depression -
the Palmer
Deep - located on the inner continental shelf of the western
Antarctic
Peninsula (64° 51.71' S, 64° 12.47' W) and subjected to
radiocarbon and
spectral analyses to provide a high resolution proxy temperature
history
spanning the past 13,000 years.
What was learned
According to the authors, the proxy records displayed five
prominent
palaeoenvironmental intervals over the past 14,000 years: (1) a
"Neoglacial"
cool period beginning 3360 years ago and continuing to the
present, (2) a
mid-Holocene climatic optimum from 9070 to 3360 years ago, (3) a
cool period
beginning 11,460 years ago and ending at 9070 years ago, (4) a
warm period
from 13,180 to 11,460 years ago, and (5) cold glacial conditions
prior to
13,180 years ago. Spectral analyses of the data revealed
that, superimposed
upon these broad climatic intervals, were decadal and
centennial-scale
temperature cycles. Throughout the current Neoglacial
period, the authors
report finding "very significant" (above the 99%
confidence level) peaks, or
oscillations, that occurred at intervals of 400, 190, 122, 85 and
70 years,
which they suggest are perhaps driven by solar variability.
Additionally,
the authors note the presence of a "Little Ice Age"
that started about 700
years before present and ended approximately 100 years ago.
What it means
The results of this study add to the mounting body of evidence
that supports
a global Little Ice Age event. It also highlights the inherent
natural
variability of climate, and suggests to us the high probability
that recent
20th century warming is not of anthropogenic origin, but the
result of
natural variability, as the earth has recovered from the
now-demonstrated
global chill of the Little Ice Age.
Copyright © 2001. Center for the Study of Carbon Dioxide
and Global Change
=========
(9) "LITTLE ICE AGE" RESEARCH: A PERSPECTIVE FROM
ICELAND
Ogilvie AEJ, Jonsson T: "Little Ice Age" research: A
perspective from Iceland
CLIMATIC CHANGE 48: (1) 9-52 JAN 2001
The development during the nineteenth and twentieth centuries of
the
sciences of meteorology and climatology and their subdisciplines
has made
possible an ever-increasing understanding of the climate of the
past. In
particular, the refinement of palaeoclimatic proxy data has meant
that the
climate of the past thousand years has begun to be extensively
studied. In
the context of this research, it has often been suggested that a
warm epoch
occurred in much of northern Europe, the north Atlantic, and
other parts of
the world, from around the ninth through the fourteenth
centuries, and that
this was followed by a decline in temperatures culminating in a
"Little Ice
Age" from about 1550 to 1850 (see e.g. Lamb, 1965, 1977;
Flohn, 1978). The
appelations "Medieval Warm Period" and "Little Ice
Age" have entered the
literature and are frequently used without clear definition. More
recently,
however, these terms have come under closer scrutiny (see, e.g.
Ogilvie,
1991, 1992; Bradley and Jones, 1992; Mikami, 1992; Briffa and
Jones, 1993;
Bradley and Jones, 1993; Hughes and Diaz, 1994; Jones et al.,
1998; Mann et
al., 1999; Crowley and Lowery, 2000). As research continues into
climatic
fluctuations over the last 1000 to 2000 years, a pattern is
emerging which
suggests a far more complex picture than early research into the
history of
climate suggested. In this paper, the origins of the term
"Little Ice Age"
are considered. Because of the emphasis on the North Atlantic in
this
volume, the prime focus is on research that has been undertaken
in this
region, with a perspective on the historiography of historical
climatology
in Iceland as well as on the twentieth-century climate of
Iceland. The
phrase "Little Ice Age" has become part of the
scientific and popular
thinking on the climate of the past thousand years. However, as
knowledge of
the climate of the Holocene continues to grow, the term now seems
to cloud
rather than clarify thinking on the climate of the past thousand
years. It
is hoped that the discussion here will encourage future
researchers to focus
their thinking on exactly and precisely what is meant when the
term "Little
Ice Age" is used.
Addresses:
Ogilvie AEJ, Univ Colorado, INSTAAR, Campus Box 450, Boulder, CO
80309 USA.
Univ Colorado, INSTAAR, Boulder, CO 80309 USA.
Iceland Meteorol Off, IS-150 Reykjavik, Iceland.
Copyright © 2001 Institute for Scientific Information
============
(10) COMMENT ON THE "CCNet SPECIAL: COMETARY IMPACTS AND
ICE-AGES"
From Dewey McLean <dmclean@vt.edu>
Dear Benny,
I enjoyed reading the "COMETARY IMPACTS AND ICE-AGES"
special by Fred Hoyle
and Chandra Wickramasinghe and agree that for life on earth, a
greenhouse is
a good thing. But, can too much of a good thing become a bad
thing? I pose
this question based on work I have done since the
late 1970s in trying to assess how we mammals fit via
reproductive
physiology into the climatology of the hot interglacial
greenhouse world
that we currently exist in, and how any additional heat load
imposed by
intensification of the greenhouse might affect us. Based
on my reading of the record (climate-physiology interactions are
complex,
and I do not claim infallibility), I must disagree with the Hoyle
and
Wickramasinghe statement that "we need all the greenhouse we
can get." So
that I will not be seen as taking those authors out of context, I
quote
their passage that most caught my attention.
"This is why the past million years has been essentially a
continuing ice-age, broken occasionally by short-lived
interglacials.
It is also why those who have engaged in uncritical
scaremongering
over an enhanced greenhouse effect raising the Earth's
temperature by a
degree or two should be seen as both misguided and dangerous. The
problem
for the present swollen human species is of a drift back into an
ice-age,
not away from an ice-age. Manifestly, we need all the greenhouse
we
can get, even to the extent of the British Isles becoming good
for the
growing of vines."
Mammals are commonly thought to be homeotherms, that is, capable
of finely
adjusting their internal core temperatures in response to
environmental
temperature changes. In fact, they are heterotherms whose core
temperatures
vary diurnally, and seasonally. And therein lies a potential
major
physiological obstacle to mammals responding, without problems,
to an
enhancement of the already high temperatures of this modern
interglacial. It
is well documented that modern mammals, in attempting to
thermoregulate in
response to high summer temperatures, shunt portions of their
blood supply
to their skin in order to reduce the core temperature. This
automatic
response reduces the flow of blood to the uterine tract where
embryos
develop. Uterine blood flow is an embryo's source of nutrients,
water,
oxygen, and hormones, and serves to transport damaging heat away
from the
uterine tract. A rise of uterine temperature of only 1.5°C,
which is
commonly achieved, can kill most embryos. Large animals, with
their small
S/V rations have a more difficult time getting rid of excessive
core heat
than do small ones. It is known that high environmental
temperatures also
cause dwarfing, and skeletal abnormalities. (Cold can also affect
reproduction, but in this discussion, warming is the issue.)
Modern high summer temperatures are already killing vast numbers
of
mammalian embryos, prior to any significant intensification of
the current
interglacial greenhouse. My best understanding, based on
discussions with
dairy science reproductive physiologists who have pioneered
research on
uterine blood flow, and from the extensive dairy science
literature, is that
about 50 percent of embryos are lost, primarily due to
environmental heat.
During the hottest summer months, the loss is higher. How high is
high?
Based on breeding records for over 12,000 Florida cattle (Badinga
et al.
1985), shows that conception rates of lactating cows decrease
sharply when
the maximum air temperature on the day after insemination exceeds
86°F
(30°C). With temperatures increasing from 75°F (23.9°C) to
90°F (32.2°C),
conceptions dropped from 52 to 32% and stayed low during the
summer months.
For Virginia cattle, optimum conception temperatures are from
50°F (10°) to
73°F (23°C) (Gwazdauskas et al. 1981). Arizona and Missouri
cattle
conceptions range from 50% in the cool months to about 20-0% in
the hot
months (Johnson 1985). High humidity, reduces the animal's
ability to lose
heat, lowering the air temperature at which core temperatures
begin to rise.
As ice age animals, we mammals have had far more experience
coping with the
cold of long, 100,000 year, glacial intervals than with the heat
of short,
10,000 year, interglacials. Intensification of the modern
interglacial
greenhouse could, potentially--if such were to occur--impose upon
us a heat
load that we have never before experienced in an evolutionary
sense.
Noteworthy is the case that mammals made it through the coldest
stages of
the last glacial, and then--during climatic instabilities, and
rapid warming
that ended the ice age, during a time of expanding living space
as ice
sheets melted, and of expanding grassland food sources--suffered
major
collapse during the Pleistocene-Holocene mammalian extinctions.
Modern
mammals are but the survivors of that extinction, and many may
already exist
near to their upper thermal limits. Incidentally, superimposed
upon the
Pleistocene-Holocene mammalian extinctions is a heat-damage
signature
composed of elimination of large body size, size reduction as a
prelude to
extinction, general dwarfing, and skeletal abnormalities.
In 1987, I was invited to present this work at NASA Langley, as
part of the
_Colloquium Lectures_, in a talk titled "Global Climate
Change and
Biological Extinction." My talk was filmed, and wound up in
the U.S. Senate,
which invited me to present it at a Senate Hearing in Washington
DC. My
testimony, titled "Climate warming and mammalian
evolution/extinctions," was
published in _The Global Environmental Protection Act of 1988_:
Pub.
100-843, U. S. Senate, Washington, DC, p. 102-113.
I have also presented it at numerous scientific meetings, and at
climate
change conferences in Egypt and Finland, etc. For an expanded
version of the
above discussions, please see my manuscript, "A climate
change mammalian
population collapse mechanism" that was published in the
proceedings volume
of the Finland conference (in Kainlauri, E., Johansson, A.,
Kurki-Suonio,
I., and Geshwiler, M., eds., _Energy and Environment_: Atlanta,
Georgia,
ASHRAE, 1991, p. 93-100). It can be accessed at:
http://filebox.vt.edu/artsci/geology/mclean/Dinosaur_Volcano_Extinction/page
s/grhskill.html
At the 1994 Houston _New Developments Regarding the KT Event and
Other
Catastrophes in Earth History_ conference, I proposed the
greenhouse-reproductive physiological coupling as a law of nature
in a talk
titled, "Proposed law of nature linking impacts, plume
volcanism, and
Milankovitch cycles to terrestrial vertebrate mass extinctions
via
greenhouse-embryo death coupling." It is in _Papers
Presented to New
Developments Regarding the KT Event and Other Catastrophes in
Earth
History_, LPI Contribution No. 825, abstract, p. 82-83, and can
be accessed
at:
http://filebox.vt.edu/artsci/geology/mclean/Dinosaur_Volcano_Extinction/pages/ghreplon.html
Cordially,
Dewey McLean
===========
(11) AND FINALLY: EUROPE IS FREAKING OUT
From National Post, 22 March 2001
http://www.nationalpost.com/news/world/story.html?f=/stories/20010321/507922.html
Mad cow disease is a real threat and has helped stoke the fear
gripping the
continent. But Europeans are now so timorous, they cannot
contemplate any
risk without panicking.
Carl Honoré
National Post
LONDON - Spend a little time in Europe, and you start to feel
nothing is
safe. Over here, cellphones cause brain damage and T-bone steaks
are lethal.
Flying economy class gives you blood clots. Even that plastic toy
bobbing in
the bathtub is toxic.
At least that is what Europeans are told. These days, hardly a
week goes by
without another health scare sweeping the continent. Never mind
that many of
the warnings are absurd, or based on flimsy science. Europeans
are now so
jittery, so convinced that modern life is a minefield, that the
merest whiff
of risk sends them scurrying for cover.
Even as incomes rise and lifespans lengthen, the continent is
gripped by a
wave of Euro-fear, a shared continental cringe.
"Europe has lost its nerve," says Frank Furedi, a
sociologist at Britain's
University of Kent and an expert on the new malaise. "Every
problem today,
however small, is represented as a major disaster."
FULL ARTICLE at
http://www.nationalpost.com/news/world/story.html?f=/stories/20010321/507922.html
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