PLEASE NOTE:
*
CCNet CLIMATE SCARES & CLIMATE CHANGE, 12 June 2002
---------------------------------------------------
"It is always amazing how science news announcements get the
facts
mixed up, and sometimes even the scientists themselves fall into
this trap. Perhaps it is the human desire to fit facts into a
neat
little package and come up with a simple explanation - in this
case the
cause for the Cretaceous-Tertiary mass extinction. The latest
announcement
that it was global warming that killed the dinosaurs is a prime
example
of this. We have known for many years that there was a major
global
warming near the end of the Cretaceous, when marine surface and
intermediate waters rapidly warmed by 3-4 C. But this event
occurred between
65.15 and 65.45 m.y. ago, and hence, 100,000 years prior to the
K/T boundary
mass extinction. During the last 100,000 years of the Cretaceous,
climate
cooled rapidly to pre- warm event cool conditions. It may well be
that this
warming killed off the dinosaurs, but this warming had
nothing to do with
the K/T boundary impact event."
--Gerta Keller, Princeton University, 12 June 2002
(1) DOES THE SUN CONTROL EVERYTHING CLIMATIC?
CO2 Science Magazine, 12 June 2002
(2) SOLAR EFFECTS ON HOLOCENE CLIMATE
CO2 Science Magazine, 12 June 2002
(3) 100,000-YEAR CLIMATE PATTERN LINKED TO SUN'S MAGNETIC CYCLES,
ACCORDING
TO A NEW ANALYSIS
Andrew Yee <ayee@nova.astro.utoronto.ca>
(4) EFFECTS OF VOLCANIC ERUPTIONS AND SUNSPOTS ON CLIMATE
UB News Service, 11 June 2002
(5) THE GREENLAND ICE SHEET IS MELTING!
CO2 Science Magazine, 12 June 2002
(6) COOLING THE EARTH
Boston Globe, 11 June 2002
(7) RE: GLOBAL WARMING, NOT COSMIC WINTER, KILLED DINOSAURS,
SCIENTISTS
CLAIM
Gerta Keller <gkeller@Princeton.EDU>
==============
(1) DOES THE SUN CONTROL EVERYTHING CLIMATIC?
>From CO2 Science Magazine, 12 June 2002
http://www.co2science.org/edit/editor.htm
For the greater part of the 20th century, Friis-Christensen and
Lassen
(1991) demonstrated a close correspondence between Northern
Hemispheric mean
surface air temperature and the length of the solar magnetic
cycle,
including the 11-year periodicity characteristic of sunspot
numbers and the
22-year oscillation of solar magnetic polarity. There is
also strong
evidence for a 420-year solar cycle (Stuiver and Braziunas, 1989)
and a
1500-year cycle (Bond et al., 2001). Now, however, comes
the granddaddy of
them all: a possible 100,000-year solar magnetic activity cycle
that may
well be the driver of the 100,000-year climatic oscillation that
is
responsible for the recurring glacial/interglacial periods of the
past two
million years.
This amazing new potential finding - which has been established
for only two
of the putative 100,000-year cycles and, hence, could still turn
out to be
spurious - is the work of Mukul Sharma of the Department of Earth
Sciences
at Dartmouth College. It is based upon the fact that the
production of 10Be
in earth's atmosphere is affected by the intensity of magnetic
activity at
the surface of the sun, as well as the earth's geomagnetic dipole
strength.
Using preexistent data pertaining to these factors that were
obtained from
several different sources, Sharma (2002) began his analysis by
compiling
200,000-year histories of relative geomagnetic field intensity
(from natural
remanent magnetizations of marine sediments) and normalized
atmospheric 10Be
production rate (also from marine sediments). Then, with
the help of a
theoretical construct describing the 10Be production rate as a
function of
the solar modulation of galactic cosmic rays (which modulation
arises from
variations in magnetic activity at the surface of the sun) and
earth's
geomagnetic field intensity, he created a 200,000-year history of
the solar
modulation factor.
This history reveals the existence of significant periods of both
enhanced
and reduced solar activity; and comparing it with the marine
ð18O record (a
proxy for global ice volume and, hence, earth's mean surface air
temperature), it was found that the two histories are strongly
correlated.
As Sharma describes it, "the solar activity has a
100,000-year cycle in
phase with the ð18O record of glacial-interglacial cycles,"
such that "the
long-term solar activity and earth's surface temperature appear
to be
directly related." Throughout the entire 200,000-year
period, for example,
Sharma notes that "the earth has experienced a warmer
climate whenever the
sun has been magnetically more active," and that "at
the height of the last
glacial maximum the solar activity was suppressed."
Hence, it was easy for
Sharma to make the final, obvious connection; and as he did so,
he set forth
as a new hypothesis the proposal that "variations in solar
activity control
the 100,000-year glacial-interglacial cycles," just as they
also appear to
control essentially all other imbedded and cascading climatic
cycles.
With the subsequent publication of Sharma's impressive analysis,
there is
now more reason than ever to look to the sun as the cause of the
global
warming of the past two centuries (Esper et al, 2002), for the
sun has now
been implicated as the causative agent of just about every scale
of climatic
change imaginable. And if the sun could free the planet
from the frigid
grip of a full-fledged ice age, it should have been a simple
thing indeed
for it to have ushered us out of the much more moderate Little
Ice Age and
into the Modern Warm Period in which we currently live, as
something clearly
did over the course of the past two centuries.
With respect to the future, we note that the current value of the
solar
modulation factor is considerably lower than it was during the
two preceding
interglacials, which suggests that it may rise even higher and
thereby
significantly extend the warming the planet has experienced to
this point in
time. Such is also suggested by the fact that the peak
warmth of the
current interglacial or Holocene is more than 2°C cooler than
the peak
warmth of the four preceding interglacials (Petit et al., 1999),
plus the
fact that the planet is currently significantly cooler than it
was during
the peak warmth of the mid-Holocene, and that it is possibly even
cooler now
than it was during the more recent Medieval Warm Period.
Consequently, as
is readily evident, there is a multitude of reasons - none of
them related
to the ongoing rise in the air's CO2 content, however - for
expecting the
earth to continue to warm even more in the coming years and
decades; and it
would thus behoove the nations of the earth to utilize their
resources in
preparing for that eventuality, rather than wasting their wealth
in an
ill-advised battle against an illusionary adversary
(anthropogenic CO2
emissions) that could well prove a godsend in helping earth's
vegetation
cope with a warming climate, as described in many places on our
website and
as articulated in Science by Cowling (1999), who wisely says we
should be
less concerned about "rising temperatures and more worried
about the
possibility that future atmospheric CO2 will suddenly stop
increasing, while
global temperatures continue rising."
These observations clearly go to the very heart of the debate
that rages
over the struggle to accept or reject the Kyoto Protocol and
anything like
it; for if the sun truly rules in the heavens above, determining
the nature
and extent of essentially all climate change on the face of the
earth, there
is not a thing that man can do to change that fact. If we are
wise,
therefore, and if what is outlined here is truly the case, we
will do what
the President of the United States, George W. Bush, long
advocated before
his recent equivocation. We will strive for economic progress for
all
nations and plan for adapting to further warming, which surely
would seem to
be headed our way.
Dr. Sherwood B. Idso, President
Dr. Keith E. Idso, Vice President
Reference
Bond, G., Kromer, B., Beer, J., Muscheler, R., Evans, M.N.,
Showers, W.,
Hofmann, S., Lotti-Bond, R., Hajdas, I. and Bonani, G.
2001. Persistent
solar influence on North Atlantic climate during the
Holocene. Science 294:
2130-2136.
Cowling, S.A. 1999. Plants and temperature - CO2
uncoupling. Science 285:
1500-1501.
Esper, J., Cook, E.R. and Schweingruber, F.H. 2002.
Low-frequency signals
in long tree-ring chronologies for reconstructing past
temperature
variability. Science 295: 2250-2253.
Friis-Christensen, E. and Lassen, K. 1991. Length of
the Solar-cycle - an
indicator of Solar-activity closely associated with
climate. Science 254:
698-700.
Petit, J.R., Jouzel, J., Raynaud, D., Barkov, N.I., Barnola,
J.-M., Basile,
I., Bender, M., Chappellaz, J., Davis, M., Delaygue, G.,
Delmotte, M.,
Kotlyakov, V.M., Legrand, M., Lipenkov, V.Y., Lorius, C., Pepin,
L., Ritz,
C., Saltzman, E., and Stievenard, M. 1999. Climate
and atmospheric history
of the past 420,000 years from the Vostok ice core,
Antarctica. Nature 399:
429-436.
Sharma, M. 2002. Variations in solar magnetic
activity during the last
200,000 years: is there a Sun-climate connection? Earth and
Planetary
Science Letters 199: 459-472.
Stuiver, M. and Braziunas, T.F. 1989. Atmospheric 14C
and century-scale
solar oscillations. Nature 338: 405-408.
Copyright © 2002. Center for the Study of Carbon Dioxide
and Global Change
==============
(2) SOLAR EFFECTS ON HOLOCENE CLIMATE
>From CO2 Science Magazine, 12 June 2002
http://www.co2science.org/subject/h/summaries/holocenesolar.htm
As science moves ever forward, ever more data are being uncovered
that point
to the primary role of the sun in orchestrating a wide range of
climatic
changes on earth. Just as small changes in solar radiation
reception at the
planet's surface are generally accepted to be the driving forces
of the
great glacial/interglacial cycles of the past two million years,
so too are
smaller millennial-scale changes in solar output being accepted
as the
causes of the smaller millennial-scale climatic changes that
usher in the
warm and cool climates typical of mini-epochs such as the
Medieval Warm
Period and Little Ice Age. Several examples of this work
are described in
what follows.
Karlen (1998) examined proxy climate data - including changes in
the sizes
of glaciers, changes in the altitude of the alpine treeline, and
variations
in tree-ring widths - related to changes in summer air
temperatures in
Scandinavia over the last 10,000 years, after which comparisons
were made
with solar irradiance data derived from 14C anomalies measured in
tree-ring
records. The author concluded from this wide array of
evidence, as well as
from data obtained from Greenland ice cores, that "the
similarity between
solar irradiation changes and climate indicate a solar influence
on the
Scandinavian and Greenland climates."
Perry and Hsu (2000) developed a simple solar-luminosity model by
summing
the amplitudes of solar radiation variances for fundamental
harmonics of the
eleven-year sunspot cycle and compared the results with
geophysical,
archaeological and historical evidence of climate variation
during the
Holocene. The model output was well correlated with the
amount of 14C in
well-dated tree rings going back to the time of the Medieval Warm
Period,
which finding, in the words of the authors, "supports the
hypothesis that
the sun is varying its energy production in a manner that is
consistent with
the superposition of harmonic cycles of solar activity."
Perry and Hsu's results were also well correlated with the
sea-level curve
developed by Ters (1987); and present in all of these records
over the
entire expanse of the Holocene was a "little ice
age"/"little warm period"
cycle with a period of approximately 1300 years. In
addition, these
climatic mini-epochs were well correlated with major historical
events.
Specifically, the authors note that "great civilizations
appear to have
prospered when the solar-output model shows an increase in the
sun's
output," while they state that such civilizations
"appear to have declined
when the modeled solar output declined."
Chambers et al. (1999) also note that recent findings in both
palaeoecology
and solar science "indicate a greater role for solar forcing
in Holocene
climate change than has previously been recognized," and
they identify a
number of "multiplier effects" that can operate on
solar rhythms in such a
way that "minor variations in solar activity can be
reflected in more
significant variations within the earth's atmosphere."
They also note that
nonlinear responses to solar variability are inadequately
represented in the
global climate models used by the Intergovernmental Panel on
Climate Change
(IPCC) to predict future greenhouse gas-induced global warming,
while at the
same time other "amplifier effects" are used to model
well-known
glacial/interglacial cycles of temperature change, suggesting
there may be a
reluctance within the IPCC bureaucracy to deal even-handedly with
different
aspects of climate change. When multiplier effects suit
their purposes - as
when they enhance the warming tendency of an increase in
atmospheric CO2
concentration, for example - they seem quite ready to use them;
but when
they don't suit their purposes - as when they amplify the
climatic impact of
a competing forcing factor, such as solar activity - they are not
so ready
to acknowledge them.
Van Geel et al. (1999) review what is known about the
relationship between
variations in the abundances of the cosmogenic isotopes 14C and
10Be - both
of which are indicators of solar activity - and millennial-scale
climate
oscillations during the Holocene, finding that "there is
mounting evidence
suggesting that the variation in solar activity is a cause for
millennial
scale climate change." Indeed, they conclude that
"the climate system is
far more sensitive to small variations in solar activity than
generally
believed" and that "it could mean that the global
temperature fluctuations
during the last decades are partly, or completely explained by
small changes
in solar radiation."
Bond et al. (2001) also studied 14C and 10Be sequestered in the
Greenland
ice cap (10Be) and Northern Hemispheric tree rings (14C), as well
as their
relationship to ice-rafted debris found in three North Atlantic
deep-sea
sediment cores. Throughout the entire 12,000-year expanse
of the Holocene,
their ice-rafted debris data revealed the presence of a recurrent
cycle of
warm and cold periods, the latter of which, in the words of the
scientists,
were "broadly correlative with the so called 'Little Ice
Age' and 'Medieval
Warm Period'."
The signal accomplishment of the study of Bond et al. was the
linking of
these millennial-scale climate oscillations and their imbedded
centennial-scale climate oscillations with similar-scale
oscillations in
cosmogenic nuclide production, which are known to be driven by
oscillations
in the energy output of the sun. In fact, they reported
that "over the last
12,000 years virtually every centennial time-scale increase in
drift ice
documented in our North Atlantic records was tied to a solar
minimum." In
light of this observation, they concluded that "a solar
influence on climate
of the magnitude and consistency implied by our evidence could
not have been
confined to the North Atlantic," suggesting that the
cyclical climatic
effects of the variable solar inferno are experienced throughout
the world.
Another important point made by Bond et al. is that the
oscillations in
drift-ice they studied "persist across the glacial
termination and well into
the last glaciation, suggesting that the cycle is a pervasive
feature of the
climate system," as would be expected for a repeatable
solar-induced
phenomenon. At two of their coring sites, in fact, they
identified a series
of such cyclical variations that extended throughout all of the
previous
interglacial and were "strikingly similar to those of the
Holocene."
In concluding their landmark paper, Bond et al. reiterate that
the results
of their study "demonstrate that the earth's climate system
is highly
sensitive to extremely weak perturbations in the sun's energy
output." They
also state that their work "supports the presumption that
solar variability
will continue to influence climate in the future."
With the ongoing development of the Modern Warm Period, the
future
envisioned by Bond et al. appears already to be upon us.
This opinion is
shared by Karlen (1998), who concludes that "the frequency
and magnitude of
changes in climate during the Holocene do not support the opinion
that the
climatic change of the last 100 years is unique," stating
bluntly that
"there is no evidence of a human influence so
far." Perry and Hsu (2000)
join in this conclusion as well, stating that the idea of the
modern
temperature increase being caused solely by an increase in CO2
concentration
"appears questionable."
We question it too.
References
Bond, G., Kromer, B., Beer, J., Muscheler, R., Evans, M.N.,
Showers, W.,
Hoffmann, S., Lotti-Bond, R., Hajdas, I. and Bonani, G.
2001. Persistent
solar influence on North Atlantic climate during the
Holocene. Science 294:
2130-2136.
Chambers, F.M., Ogle, M.I. and Blackford, J.J. 1999.
Palaeoenvironmental
evidence for solar forcing of Holocene climate: linkages to solar
science.
Progress in Physical Geography 23: 181-204.
Karlen, W. 1998. Climate variations and the enhanced
greenhouse effect.
Ambio 27: 270-274.
Perry, C.A. and Hsu, K.J. 2000. Geophysical,
archaeological, and
historical evidence support a solar-output model for climate
change.
Proceedings of the National Academy of Sciences USA 97:
12,433-12,438.
Ters, M. 1987. Variations in Holocene sea level on
the French Atlantic
coast and their climatic significance. In: Rampino, M.R.,
Sanders, J.E.,
Newman, W.S. and Konigsson, L.K. (Eds.) Climate: History,
Periodicity, and
Predictability. Van Nostrand Reinhold, New York, NY, pp.
204-236.
Van Geel, B., Raspopov, O.M., Renssen, H., van der Plicht, J.,
Dergachev,
V.A. and Meijer, H.A.J. 1999. The role of solar
forcing upon climate
change. Quaternary Science Reviews 18: 331-338.
Copyright © 2002. Center for the Study of Carbon Dioxide
and Global Change
==============
(3) 100,000-YEAR CLIMATE PATTERN LINKED TO SUN'S MAGNETIC CYCLES,
ACCORDING
TO A NEW ANALYSIS
>From Andrew Yee <ayee@nova.astro.utoronto.ca>
Office of Public Affairs
Dartmouth College
Hanover, New Hampshire
Contact:
Sue Knapp, sue.knapp@dartmouth.edu,
(603) 646-3661
June 6, 2002
100,000-YEAR CLIMATE PATTERN LINKED TO SUN'S MAGNETIC CYCLES,
ACCORDING TO A
NEW ANALYSIS
Thanks to new calculations by a Dartmouth geochemist, scientists
are now
looking at the earth's climate history in a new light.
Mukul Sharma, Assistant Professor of Earth Sciences at Dartmouth,
examined
existing sets of geophysical data and noticed something
remarkable: the
sun's magnetic activity is varying in 100,000-year cycles, a much
longer
time span than previously thought, and this solar activity, in
turn, may
likely cause the 100,000-year climate cycles on earth. This
research helps
scientists understand past climate trends and prepare for future
ones.
Published in the June 10 issue of Earth and Planetary Science
Letters
(Elsevier, volume 199, issues 3-4), Sharma's study combined data
on the
varying production rates of beryllium 10, an isotope found on
earth produced
when high-energy galactic cosmic rays bombard our atmosphere, and
data on
the past variations in the earth's magnetic field intensity. With
this
information, Sharma calculated variations in solar magnetic
activity going
back 200,000 years, and he noticed a pattern.
Over the last 1 million years, the earth's climate record has
revealed a
100,000-year cycle oscillating between relatively cold and warm
conditions,
and Sharma's data on the sun's magnetic activity corresponded to
the earth's
ice age history.
"Surprisingly, it looks like solar activity is varying in
longer time spans
than we realized," says Sharma. "We knew about the
shorter cycles of solar
activity, so maybe these are just little
cycles within a larger cycle. Even more surprising is the fact
that the
glacial and interglacial periods on earth during the last 200,000
years
appear to be strongly linked to solar activity."
Sharma's calculations suggest that when the sun is magnetically
more active,
the earth experiences a warmer climate, and vice versa, when the
sun is
magnetically less active, there is a glacial period. Right now,
the earth is
in an interglacial period (in between ice ages) that began about
11,000
years ago, and as expected, this is also a time when the
estimated solar
activity appears to be high.
Beryllium 10 is useful for studying the geology from hundreds of
thousands
of years ago mainly because it has a half-life of about one and a
half
million years. In addition, there are two key factors that have
affected
beryllium 10 production over the last 200,000 years: the earth's
magnetic
field and the sun's magnetic activity. When there are
high-intensity solar
magnetic storms, more charged particles are interacting with
cosmic rays,
and less beryllium 10
is produced. Likewise, the earth's magnetic field changes the
flux of cosmic
rays into and out of the atmosphere.
Since the production rate of beryllium 10 and earth's magnetic
field
intensity are known for the last 200,000 years, Sharma could
calculate solar
magnetic activity for this time period.
"I took sets of existing, independent data and made new
comparisons and
calculations," says Sharma. Then he went a step further to
make a connection
with the history of ice ages by looking at oxygen isotopes in the
oceans,
which reveal the history of how much ice was at the poles and are
therefore
a measure of average global surface temperature.
"I compared the estimated past variations in the solar
activity with those
of the oxygen isotopes in the ocean. Although there is a strong
relationship
between solar activity and oxygen isotopic
variations, it is too early to say exactly what is the mechanism
though
which the sun is influencing the terrestrial climate."
One explanation of the 100,000-year cycle was offered by the
Milankovitch
Theory of Ice Ages in the 1940s, which suggested that the
cyclical
variations in the earth's orbit around the sun result in the
earth receiving
varying amounts of solar radiation that, in turn, control the
climate. This
explanation is under dispute because the variations of the solar
energy in
relation to the changes in orbit are very small. Other current
research
focuses on past variations in the sun's irradiance, or heat
intensity (as
opposed to the magnetic activity).
Sharma notes that more analysis is needed to test his theory.
"I've only
looked at 200,000 years. My calculations need to be verified for
a million
years, for instance. Plus, regarding the current global warming
debate, it
still needs to be examined if the role of solar activity will
exacerbate the
rising temperatures that result from carbon dioxide buildup in
the
atmosphere."
This work was supported by Dartmouth College, the Max Planck
Institute and
by a grant from the National Science Foundation.
IMAGE CAPTION:
[ http://www.dartmouth.edu/~news/releases/june02/climate.shtml
] Mukul Sharma
in his lab, where equipment processes geological/cosmic samples
to measure
isotopic ratios. (Photo by Joe Mehling '69.)
=============
(4) EFFECTS OF VOLCANIC ERUPTIONS AND SUNSPOTS ON CLIMATE
>From UB News Service, 11 June 2002
http://www.buffalo.edu/news/fast-execute.cgi/article-page.html?article=57350009
Study of Dust in Ice Cores Shows Volcanic Eruptions Interfere
with the
Effect of Sunspots on Global Climate
Release date: Tuesday, June 11, 2002
Contact: Ellen Goldbaum, goldbaum@buffalo.edu
Phone: 716-645-5000 ext 1415
Fax: 716-645-3765
BUFFALO, N.Y. -- University at Buffalo scientists working with
ice cores
have solved a mystery surrounding sunspots and their effect on
climate that
has puzzled scientists since they began studying the phenomenon.
The research, published in a paper in the May 15 issue of
Geophysical
Research Letters, provides striking evidence that sunspots --
blemishes on
the sun's surface indicating strong solar activity -- do
influence global
climate change, but that explosive volcanic eruptions on Earth
can
completely reverse those influences.
It is the first time that volcanic eruptions have been identified
as the
atmospheric event responsible for the sudden and baffling
reversals that
scientists have seen in correlations between sunspots and
climate.
"Knowing the mechanisms behind past climate changes is
critical to our
understanding of possible future changes in climate, such as
global warming,
and for assessing which of these changes are due to human
activities and
which arise naturally," explained co-author Michael Stolz,
doctoral
candidate in the Department of Physics in UB's College of Arts
and Sciences.
According to the UB researchers, their work reveals two different
mechanisms
by which climate is affected by cosmic rays, charged particles
that stream
toward Earth and which are strongly influenced by solar activity.
"For a long time people have tried to find out whether, for
example, periods
of maximum sunspots will influence the climate to behave in a
certain way,"
said Michael Ram, Ph.D., professor of physics at UB and co-author
on the
paper.
"Whenever scientists thought they had discovered something,
say, they were
seeing a positive correlation between temperature and sunspots,
it would
continue like that for several years and, all of a sudden, there
would be a
reversal and, instead, they would start to see a negative
correlation," said
Ram.
"There seemed to be no consistent relationship between what
the sun was
doing and what the climate was doing," he said.
To truly confirm any connection between sunspots and climate, a
consistent
correlation would have to be observed over a long period,
covering many
solar cycles, Ram explained.
That's what he and his graduate students and co-authors have done
with their
study of ice cores, long cylinders of ancient ice from Greenland
that serve
as a frozen archive in that they record climate details from
thousands of
years ago.
"This is the beauty of working with ice cores," said
Ram. "They go back
100,000 years, so we can study how dust concentrations vary along
the ice
core, reflecting past-atmospheric dust concentrations."
Plain old dust, Ram added, holds the key in these experiments
because it
reflects how dry conditions were in a particular year.
"Dust is a very sensitive parameter of climate," he
explained.
Drawing on climate data derived from ice cores obtained through
the
Greenland Ice Sheet Project 2, (GISP2), the scientists used
laser-light
scattering techniques to determine the level of dust in the
atmosphere for
roughly the past 300 years, which is how far back sunspot data
have been
recorded.
The scientists started out with the assumption that a low level
of cosmic
rays on Earth resulting from high sunspot activity would lead to
less cloud
cover and less rain, with resulting high dust levels.
"This was true for the first three or four solar cycles we
studied, from
about 1930 to 1962, but then the correlation reversed itself,
demonstrating
that the mechanism couldn't be what we thought," said Ram.
It turned out that during those 32 years of positive sun/dust
correlation,
there was relatively little explosive volcanic activity
worldwide. The
researchers found that the same conditions existed between 1860
and 1882.
Each of these relatively "quiet" periods came to an end
with increased
volcanic activity.
For example, in 1883, the Indonesian volcano Krakatau erupted in
one of the
deadliest volcanic disasters, killing 36,000 people. At exactly
the same
time, the data started to exhibit low dust concentration whenever
there was
high sunspot activity, a correlation that violated the
scientists' original
assumptions.
"By carefully studying the timing of other volcanic
eruptions, we found that
they coincided with all of the correlation reversals between
sunspots and
climate," said Ram.
A chart in the paper shows how six major volcanic eruptions
between 1800 and
1962 occurred during precisely the same years when there were
reversals in
the correlation between sunspot activity and climate.
That revelation provided a further insight into how sunspots
affect climate.
"All energy comes from the sun, but the change in visible
radiation from the
sun during any one solar cycle is less than one half of a
percent,"
explained Stolz. "Scientists have said it's impossible that
so small a
change could influence any signal in the climate. But here we
have evidence
to show that it's not just radiation energy from the sun that is
affecting
climate, it's the solar-modulated cosmic rays that have a strong
influence
because of their impact on cloud cover."
With fewer clouds, and therefore less rain, the scientists
reasoned, maximum
sunspots should cause levels of atmospheric dust to rise.
"That is true sometimes," said John Donarummo, Jr., UB
doctoral candidate in
the UB Department of Geology and a co-author on the paper.
But, the researchers discovered, during periods of high volcanic
activity,
high sunspot activity also results in high levels of atmospheric
dust.
According to Donarummo, it long has been known that volcanoes add
more dust
and more sulfates to the atmosphere.
The UB team discovered that these additional sulfates cause
cosmic rays to
have a more pronounced effect on Earth by spurring the formation
of small
droplets in the atmosphere that, in turn, cause the formation of
a type of
cloud that does not produce rain.
"During these times of high volcanic activity, the
sunspot/climate
correlation reverses and dust levels rise, even in the absence of
high
sunspots," explained Stolz.
The work was funded in part by National Science Foundation.
===========
(5) THE GREENLAND ICE SHEET IS MELTING!
>From CO2 Science Magazine, 12 June 2002
http://www.co2science.org/journal/2002/v5n24c2.htm
Reference
Fahnestock, M., Abdalati, W., Joughin, I., Brozena, J. and
Gogineni, P.
2001. High geothermal heat flow, basal melt, and origin of
rapid ice flow
in central Greenland. Science 294: 2338-2342.
What was done
The authors used airborne ice-penetrating radar data to determine
the extent
and rate of basal melting for a large portion of the Greenland
Ice Sheet,
while employing other geophysical data to study the underlying
topography of
the area.
What was learned
The authors discovered a large region of rapid basal melting of
the
Greenland Ice Sheet in the source area of the rapidly flowing ice
stream
that drains the north side of the summit dome. This melting
was further
shown to be occurring above a 1000-m high topographic disturbance
that
exhibits a dramatic increase in bed roughness, which suggests, in
the words
of the authors, that "it has undergone less erosion and may
be younger than
the surrounding bed." Melt rates of this area are
indicative of geothermal
fluxes 15 to 30 times greater than the continental background
rate.
What it means
The authors note that free-air gravity measurements over the
primary area of
basal melting and the high geothermal fluxes experienced there
are
comparable in magnitude and spatial extent to those of the
Yellowstone
caldera, and that localized peaks in gravity and rough-surfaced
bed
topography are suggestive of local extrusive structures.
Hence, they
conclude that their "limited geophysical evidence suggests
the presence of a
caldera structure," which leads to "rapid and extensive
basal melting in
Greenland that has a direct effect on ice flow."
Will this finding take a little "heat" off the ongoing
rise in the air's CO2
content when it comes to identifying something to blame - which
must be
done, of course - for the10-cm-per-year melting of ice above the
apparent
caldera? Actually, there may not be a need to do so; for
the authors note
that the findings of several studies of thickening and thinning
in the high
interior of the ice sheet suggest that "the present ice
sheet is close to
being in balance with the patterns of basal melting" they
discovered. And
if a natural volcano can't bring about the demise of the
Greenland Ice
Sheet, it's very likely the human volcano won't either.
Copyright © 2002. Center for the Study of Carbon Dioxide
and Global Change
===========
(6) COOLING THE EARTH
>From Boston Globe, 11 June 2002
http://www.boston.com/dailyglobe2/162/science/Cooling_the_Earth+.shtml
President Bush is counting on a new, untested field to counter
global
warming by sucking greenhouse gases out of the air
By Wendy Williams, Globe Correspondent, 6/11/2002
he hot new field in engineering is breathtaking in its ambition.
These
so-called ''geo-engineers'' want nothing less than to turn down
the Earth's
temperature by altering the chemistry of the air, soaking up and
storing
away carbon dioxide that prevents heat on the planet surface from
dissipating into space.
The payoff would be extraordinary, too. If ''carbon
sequestration'' works,
it could allow governments to head off the worst effects of
global warming
without sacrificing all the sport-utility vehicles and other
fossil-fuel-burning staples of modern life that are causing a
buildup of
carbon dioxide in the atmosphere in the first place.
So, scientists around the globe are engaged in intriguing, if
bizarre,
experiments to get rid of a gas once thought of as harmless -
genetically
engineering plants to absorb more carbon, learning to grow ocean
plankton
blooms that will do the same, and looking for places on the ocean
floor or
depleted oil wells where carbon could be stored virtually
forever.
But, intriguing as these ideas sound, a growing number of
scientists,
environmental organizations and energy officials fear that the
Bush
administration has become prematurely enamored of this
geo-engineering,
counting on it to blunt a predicted 3- to 9- degree Fahrenheit
global
temperature increase over the next century.
''I get uneasy when we talk about managing on this scale,'' said
Duke
University ecologist Robert Jackson, an author of a recent study
in Nature
warning that some regions of the nation and globe may be reaching
their
carbon-storage limits. ''It's a dangerous strategy ... and it's
unlikely to
really make a difference. At best, it can buy us a little time.''
Yet, a new report from the US Environmental Protection Agency
states that
carbon sequestration is already working. Trends such as the
growth of US
forests, which absorb carbon dioxide, and even the landfilling of
suburban
yard waste, preventing it from releasing CO2 as it decomposes,
are
offsetting 15 percent of US carbon releases each year, the report
states.
Deliberate attempts to encourage carbon-storing initiatives such
as
tree-planting could create a $5 billion-a-year industry by 2035,
according
to the US Department of Agriculture.
Bush has distanced himself from the EPA report, but not because
of the
carbon-sequestration findings. In a speech last June, Bush said
carbon
sequestration ''offers great promise to significantly reduce''
carbon-dioxide emissions. And the US Department of Energy
increased its
sequestration-research budget by 80 percent last year to $32.1
million, with
a request for $54 million in the next fiscal year.
Some of the federal government's own scientists who study global
warming are
wary of putting too much emphasis on carbon sequestration. Pieter
Tans, the
National Oceanic and Atmospheric Administration's chief scientist
at the
Climate Monitoring and Diagnosis Lab in Boulder, said ecologists,
biologists, engineers and atmospheric researchers have yet to
agree on how
much carbon is stored by various natural processes, or on how
useful
engineering techniques mimicking natural processes might be.
Before a major
policy decision is made, Tans and others warned, more research
and public
debate is necessary.
''If we decide to go hard for agricultural sequestration in
soils,'' Tans
said, ''that's a significant shift. There's all kinds of social
consequences. But the most important thing we can do is to get
serious about
energy efficiency and conservation. I see very little of that.''
Administration officials say carbon sequestration is only part of
a broader
plan to slow the buildup of carbon dioxide and other so-called
''greenhouse
gases.''
''There are essentially three ways to reduce greenhouse gas
emissions,''
explained Robert Kane, the Energy Department's climate change
issue manager.
''You can reduce them by using energy efficiently. You can switch
fuels, as
in changing from coal to gas. Or you can sequester the carbon you
produce,
either by direct of indirect means. All three of those legs are
important to
an overall carbon mitigation picture.''
Debate over these questions in scientific journals has
accelerated over the
past six months. Oceanographers warn that turning oceans into a
carbon
garbage could destroy underwater ecosystems they know little
about.
Geologists warn that injecting CO2 into underground reservoirs
could
backfire in many unexpected ways. Ecologists warn that
''geo-engineering''
is more complicated than was once assumed. A Nature report last
fall
authored by 30 scientists stressed that absorption of carbon by
various
organisms can change during their life cycles, and may be less
predictable
than was once assumed.
''We know that the carbon-storage capacity of these ecosystems is
finite,''
said one of the authors, biologist Jerry Melillo of the Marine
Biological
Laboratory's Ecosystems Center in Woods Hole. ''Once it is
filled, the rate
of climate change will accelerate, as will the rate of
climate-change
impacts.''
And scientists are only beginning to debate the merits of
individual
initiatives to ''scrub'' the atmosphere in this fashion. Proposed
technologies for capturing and hiding carbon can be divided into
two
subcategories - technologies that work right at the smokestack,
at the point
of emission, and technologies that attempt to draw down CO2
already
dispersed throughout the atmosphere. Many specialists said they
agreed that
at-the-smokestack technologies would help a great deal. Such
''scrubbing''
currently does protect the atmosphere from another pollutant,
sulfur
dioxide. Industry dislikes this approach, however, because of the
cost,
estimated by the Department of Energy at $100 to $300 a ton of
CO2 removed.
''The goal of the program is to reduce the cost to $10 or less,''
according
to the Department of Energy Web site. ''Achieving this goal would
save the
US tens of trillions of dollars.''
Forestry projects are particularly controversial. Through
photosynthesis and
other biological processes, trees take carbon dioxide out of the
atmosphere,
separate the compound and store the carbon in trunks and roots.
Believing
trees and plants could ''scrub'' the atmosphere, some scientists
and
environmental groups want to encourage both forest preservation
and
replanting.
A number of questions remain, however. How much carbon can be
stored in a
particular region remains unclear. But even more complex is the
question of
choosing which kinds of forestry projects should be allowed and
how they can
be monitored over the decades to ensure the carbon stored in the
trees does
not somehow escape. ''What if a fire occurs?'' researchers ask.
Accounting for sequestered carbon could become an Enron-style
nightmare.
Scientists and environmental groups worry about traders
''gaming'' the
system.
Sequestration and policy expert David Keith of Carnegie Mellon
University
finds the emphasis on cheapness to be a matter of major concern.
''If the existence of low-cost biological sinks encourages
postponement of
effective action on emissions mitigation, and if such sinks prove
leaky,''
he said, ''then the existence of these sinks poses a moral
hazard.''
Lobbying groups are all over the map on this question. Many
European
organizations have rejected forestry projects altogether. The
Sierra Club
stated that reforesting the world is a laudable goal, but it
shouldn't be
used in lieu of ending at-the-smokestack pollution. But the
Nature
Conservancy is already overseeing several projects in Belize
involving
long-term rain-forest protection.
And the American Forest and Paper Association, an industry
lobbying group,
wants its members to receive carbon credits for trees that
eventually will
become marketable products such as lumber, furniture and even
books. ''It's
a scientific fact that carbon is stored in wood and paper
products,''
spokesman Mitch Dubensky said.
Companies are already carrying out carbon ''trades'' where
carbon-dioxide
polluters pay a third party for a carbon-reducing program to
offset their
emissions. A report issued by the Pew Center on Global Climate
Change
estimates that the cost of sequestering a ton of carbon through
forestation
currently ranges from $1 to $3 a metric ton. Many companies -
believing
governments will soon require them to reduce carbon emissions -
are buying
now, at these low prices, hoping to cover their bases before
prices go up.
Whatever is ultimately decided, many scientists and most
environmental
groups stress the importance of caution. John G. Rogers, formerly
acting
head of the US Fish and Wildlife Service and currently with the
North
Carolina-based Conservation Fund, said he believes only
reforestation
projects that permanently recover habitat on marginal cropland
should be
allowed.
''I, personally, and the Conservation Fund, in general, would be
worried
about anything artificial, whether it's some kind of
fertilization of
forests, whether it's manipulating the oceans,'' he said. ''You
might be
creating a bigger problem than you're solving.''
Research for this piece was supported by the Fund for
Investigative Journalism.
This story ran on page B7 of the Boston Globe on 6/11/2002.
© Copyright 2002 Globe Newspaper Company.
==========
(7) RE: GLOBAL WARMING, NOT COSMIC WINTER, KILLED DINOSAURS,
SCIENTISTS
CLAIM
>From Gerta Keller <gkeller@Princeton.EDU>
Dear Benny
It is always amazing how science news announcements get the facts
mixed up,
and sometimes even the scientists themselves fall into this trap.
Perhaps it
is the human desire to fit facts into a neat little package and
come up with
a simple explanation - in this case the cause for the
Cretaceous-Tertiary
mass extinction. The latest announcement that it was global
warming that
killed the dinosaurs is a prime example of this. We have known
for many
years that there was a major global warming near the end of the
Cretaceous,
when marine surface and intermediate waters rapidly warmed by 3-4
C. But
this event occurred between 65.15 and 65.45 m.y. ago, and hence,
100,000
years prior to the K/T boundary mass extinction. During the last
100,000
years of the Cretaceous, climate cooled rapidly to pre-warm event
cool
conditions. It may well be that this warming killed off the
dinosaurs, but
this warming had nothing to do with the K/T boundary
impact event.
There is no doubt that the warming was related to a major change
in the CO2
level, and that it could be either Deccan volcanism which peaked
between
65.4-65.2 m.y. ago, a major impact event, or both. But this still
also
leaves us with the evidence of a major impact at the K/T boundary
65 m.y.
ago. There is increasing evidence from impact glass spherules, Ir
and Pd
anomalies that multiple impacts (e.g. comet shower) are a more
likely
explanation for the observed climate change, mass extinction and
delayed
recovery of life, than a single impact at Chicxulub on the
Yucatan
peninsula. The end Cretaceous rapid warming was just one event in
this
sequence.
References:
Keller, G., 2002. GSA Spec. Paper 356, 145-161.
Keller, G., 2001. J. Planetary and Space Science, 49,
817-830.
Hoffmann et al., 2000, EPSL 180, 13-27.
Li, L., and Keller, G., 1998. Geology, 26: 995-99.
Kucera, M., and Malmgren, B. A., l998. Paleo-3, 138:1-15.
Olsson, R., K., et al., 2001. J. Foram. Res., 31(3):
275-282.
Barrera, E., l994. Geology, 22: 877-880.
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