Note # 48:
While we claim
no particular expertise in policy matters, we note expert opinion to the effect that
''. . .stabilization [of atmospheric CO2 levels] requires an eventual and sustained reduction of emissions to substantially below current levels'' [Wigley TML, Richels R and Edmonds J, Economic
and environmental choices in the stabilization of atmospheric CO2 concentrations,
Nature 379, 240-3 (1996)] and we estimate that ''substantial'' worldwide reduction
in fossil fuel usage over the next several decades will not occur without substantial
likelihood of inducing major conflict.
JULES VERNE GUN
BY SCOTT R. GOURLEY
PM Illustrations by Harold Smelcer
Published on: April 1998
An ambitious plan to change the way we launch satellites will fulfill the science-fiction
writer's dream.
In his 1865 novel From The Earth To The Moon, author Jules Verne describes a post-Civil War society
in which the convened members of the fictitious Baltimore Gun Club lament the sudden lack of artillery activities.
Their boredom is soon broken by a speech from the club's president, who outlines a bold plan to use a giant cannon to fire
a projectile to the Moon. One of the fictional club members awed by the plan is named Tom Hunter. Coincidentally, a very real
visionary with the same last name may make author Verne's fantasy come true.
"Jules Verne was a true visionary in an era when you needed visionaries," explains John
Hunter. "Now, the problem is that we have too many visionaries and not enough doers." Hunter is standing in his cluttered
Southern California office, where he has just drawn a diagram of comparative escape velocities on the blackboard. As president
and founder of the Jules Verne Launcher Co., Hunter is combining Verne's vision with his own actions. Quite simply, he intends
to use gas-powered launchers as an effective and inexpensive way of propelling satellites into orbit.
Hunter's quest began when he started working at Lawrence Livermore National Laboratory (LLNL) in 1985. One of his first projects
at the lab involved the concept of an electromagnetic space launcher. "The cost per joule of just about any kind of electric
gun is so high that it's basically prohibitive," Hunter says. During a technical discussion at Livermore Lab, it was suggested that he look at the potential of "gas guns," systems that utilize
a pump tube filled with heated and pressurized gas to drive projectiles at extremely high velocities. In fact, Hunter's search
of the library database revealed that a NASA gas gun had achieved a projectile speed of 6.84 miles per second back in 1966.
But he knew that higher velocity was needed. "At that point I knew, just like particle theory, that 99% of the people were
just going along the well-worn path because someone had money or a cool idea. But they weren't being rigorous thinkers about
solving the problem."
The solution that emerged involved the use of a gas gun with multiple injectors. Hunter's
computer simulations suggested that such a system would work very well. "The velocities I was getting to were much higher
than had ever been done before with conventional gas guns." Hunter then conducted a 2-month lab project to demonstrate the
antitank potential of a single-stage hydrogen gas gun operating at room temperature. "I got 1.5 miles per second. The results
were within 1% of my code predictions on six data points." Based on the computer model's accuracy and the quick completion
of the project, Hunter was funded for a 3-month effort to develop a 2-stage gas-gun precursor to a space launcher. The effort
produced a 10-ft.-long gas gun that achieved a firing velocity of 5 miles per second.
"[That] still exceeds the velocity record for any rail gun ever built," Hunter says. "Gas
guns routinely achieve 5 miles per second. That's what's so phenomenal about them. The beauty is that to access space, 4.35
miles per second is where the action really gets hot and heavy. At 4.35 miles per second, you can launch a 10-ton vehicle
and get 33% fraction into LEO [low Earth orbit]. If you start with 11 tons, you're going to have 7275 pounds in LEO."
The success of the 10-ft. prototype justified additional LLNL research and development
funding for a "space gun" project identified as Super High Altitude Research Project, or SHARP. (Hunter chose the name in
recognition of the U.S. government's HARP Super Gun project, which was conducted during the mid-1960s with standard powder
technology.)
Located at LLNL Site 300, SHARP is the world's largest gas gun. The 425-ft.-long system
was built in a unique L-shaped design with a 270-ft.-long combustion section and pump tube mounted at a right angle to the
155-ft.-long launch tube. The original design was driven by a desire to minimize the height of any supporting gantry that
would be required to elevate the tube for space launch.
"SHARP has only gotten to 1.92 miles per second because we're launching fairly big masses
and we haven't jacked up the pressures very high," Hunter says. He adds that achieving the requisite 4.35 miles per second
is "totally doable," based on both computer-model and lab-gun experience.
First,
Hunter will build and fire a prototype system dubbed the "Micro Launcher." "Our Micro Launcher design is so small that you'll
hardly see the projectile-maybe only 50 mils or one-twentieth of an inch," Hunter says. "That sounds crazy, right? I helped
build the world's biggest gun," he says jokingly, clearly aware of the irony.
Hunter
is also devoting considerable attention to the design of specially hardened satellite packages and has recruited experienced
satellite designers for his team of engineers. They will use the prototype systems to ensure satellite stability as it leaves
the launch tube, as well as to address g-force hardening. The largest commercial guns will subject the satellites to 1000
g's for approximately 1 second. Although this is easily met by circuit designs, it may require hardening of components like
solar cells or deployable antenna structures.
Based
on SHARP experience, Hunter's engineers predict that the guns can easily be fired once per working day. Given a rate of 300
launches per year and a payload of 10,000 pounds per launch, the system has the potential of placing approximately 1500 tons
a year into LEO. Moreover, at a target launch cost per pound of about one-twentieth of a modern rocket launch, the company
estimates a breakeven point between the first 50 and 100 launches.
"The
house odds wouldn't bet on us," Hunter says. "That's not a condemnation of house odds. That's just the way that the house
works. But this is going to happen."
The
SHARP firing sequence begins with the ignition of a methane gas mixture at one end of the steel pump tube. That explosion
drives a 1-ton steel piston down the pump tube, which has been filled with pressurized hydrogen gas. The piston rapidly compresses
the gas to 60,000 psi in the high-pressure section (below), destroying a coupling holding the projectile in the attached depressurized
launch tube. The projectile is driven down the 4-in.-dia. tube at an extremely high speed and it bursts through a thin plastic
sheet covering the end of the gun. All recoil forces are absorbed through the use of three sleds-two 100-ton sleds and one
10-ton sled-mounted on railroad tracks.
Krakatoa helps to keep Earth cool By Roger Highfield, Science Editor (Filed: 09/02/2006)
The huge eruption of Krakatoa is still keeping the world cool
and damping down the rate of sea level rise caused by climate change, thanks to the ashes and aerosols that it spewed out
in 1883.
More than six cubic miles of rock, ash, and pumice were ejected
from the volcano, near the Indonesian island of Rakata in the Sunda Strait.
The explosion generated the loudest sound in human history,
and was heard from more than 2,500 miles away.
According to a study published today in the journal Nature,
the sulphate aerosols and a worldwide volcanic dust veil acted as a solar radiation filter, reducing the amount of sunlight
reaching the surface of the earth.
In the year following the eruption, global temperatures were
lowered, keeping the Earth's surface waters relatively cool.
To reveal how the cooling lasted for decades longer than this,
Dr Peter Gleckler and others at the Lawrence Livermore National Laboratory, California, and colleagues in Reading University
and Boulder, Colorado, used computer simulations from 12 state-of-the-art climate models.
They suggest that the temperature anomaly persisted for decades
because the cooled surface water was subsequently drawn deeper into the ocean.
The volume average temperature of oceans has warmed by roughly
0.37C in recent decades due to greenhouse gases. While seemingly small, this corresponds to a sea level rise of several centimetres
and does not include the effect of other factors such as melting glaciers.
But that sea level jump would have been even greater had it
not been for volcanic eruptions over the last century, Dr Gleckler said.
"Ocean warming and sea level would have risen much more if
it weren't for volcanoes," he added.
copyright 2006 London Telegraph
Trading Rockets for Space
Elevators
Stu Hutson for National Geographic News
August
25, 2005
Blasting
a space shuttle away from Earth's gravity and through atmospheric friction at 15,000 miles an hour (24,140 kilometers an hour)
is the most dangerous and costly part of every mission.
Why not just take
an elevator instead? Thanks to a new development in the manufacture of molecule-size cylinders known as carbon nanotubes,
that may one day be a viable option.
In theory, space elevators
need a fixed line, or cord, that stretches from an anchor on Earth to a station out in space. The station acts like a counterweight,
forever "held" above the planet by the centrifugal force from Earth's rotation.
A tram-like vehicle
equipped with electric motors could climb this tether from Earth's surface into space at a safer speed than rocket alternatives.
In theory, space elevators
would need far less energy than conventional space launches. As a result, the cost of transporting matter could drop from
U.S. $20,000 a kilogram (the going rate for the space shuttle) to as little as $250 a kilogram.
"This is a trillion-dollar
moneymaker for a ten billion dollar investment," said Bradley Edwards, whose work with Los Alamos National Laboratory and
the NASA Institute for Advanced Concepts has made him a go-to expert on space elevators. "Some of the largest companies in
the world are just waiting for the word that this is possible."
Conquering Carbon
The word on cheap
space freight rates won't be sounded until at least one major obstacle is overcome: developing a strong enough material for
the tether. Scientists believe they found the fibers for that material—carbon nanotubes—in 1991.
The tubes are molecules
of carbon linked together in a shape that resembles a Chinese finger trap. Carbon is among the stickiest elements, and these
tubes hold together hundreds of times better than Kevlar, the material used to make bullet-proof vests.
In theory, a space
elevator tether made of carbon nanotubes would look and feel like a span of three-foot-wide (one-meter-wide) plastic wrap
that stretched skyward as far as the eye could see. It could be rolled up and simply dropped to the ground from space-based
orbit.
The problem with this
scenario is that individual carbon nanotubes are only millimeters tall and nanometers wide. (A nanometer is a billionth of
a meter.) No one has successfully woven the tubes together in a way to make sheets that are as strong as their individual
fibers.
But Ray Baughman,
who directs the Nanotech Institute at the University of Texas at Dallas, and his team
have developed what could be a first step.
The
scientists have produced yards of woven, pure nanotubes in sheets two inches (five centimeters) wide. The method is easily
scalable to produce sheets of any dimension and can roll them out as fast as 33 feet (7 meters) a minute.
The technique, which
is described in the August 19 issue of the journal Science, begins by building nanotubes. Gaseous carbon atoms are
coaxed to deposit themselves onto a specially prepared surface in an oven. The surface "catches" the atoms in such a way that
they cling to each other and form into tubes.
Baughman likens the
result to a tiny bamboo forest. The researcher catches the row of tubes from the "forest edge" with an adhesive strip. As
the first row is pulled away, the second row clings to its neighbor and is also pulled away. Eventually, enough of a sheet
is pulled away that it can be reeled up with a plastic roller.
But for now, the resulting
"fabric" isn't nearly as strong as Kevlar.
Versatile Tubes
Other scientists have
experimented with producing nanotube-based materials by embedding the tubes in polymers—large, chain-like molecules
made from repeating links of smaller molecules. Rodney Andrews from the University of Kentucky has produced fibers this way that are five times stronger than
Baughman's.
"What's good about
Ray's [product] is that it's made entirely out of nanotubes," Edwards said. "And the final material that will make up the
[space elevator] tether will probably have to be at least 50 percent nanotubes."
Making the new carbon
nanotube sheets stronger is a matter of finding better pulling methods and more advanced surfaces. Still, research won't produce
a viable tether for some time, probably a few decades, Baughman said.
Edwards's own company,
Carbon Designs Inc., also develops nanotube-based materials. He and other experts are slightly more optimistic, putting the
estimated time of arrival of a space elevator tether at less than 20 years.
So don't pack your
bags for the first space elevator trip anytime soon. But in the near future you might see carbon nanotubes coming to more
commonplace products.
Carbon nanotubes have
other interesting properties besides their strength, and Baughman has already demonstrated that their conductivity can make
his sheets glow, providing whole surfaces that give light.
He's also shown that
a sheet placed between pieces of glass will heat up when electrified, and may make for the perfect in-glass radio antenna.
|
Space Ring
Could Shade Earth and Stop Global Warming
By Robert Roy Britt Senior Writer posted: 27 June 2005 02:14 pm ET |
|
From: http://www.livescience.com/technology/050627_warming_solution.html
A wild idea to combat global
warming suggests creating an artificial ring of small particles or spacecrafts around Earth to shade the tropics and moderate
climate extremes.
There would be side effects,
proponents admit. An effective sunlight-scattering particle ring would illuminate our night sky as much as the full Moon,
for example.
And the price tag would knock
the socks off even a big-budget agency like NASA: $6 trillion to $200 trillion for the particle approach. Deploying tiny spacecraft
would come at a relative bargain: a mere $500 billion tops.
But the idea, detailed today
in the online version of the journal Acta Astronautica, illustrates that
climate change can be battled with new technologies, according to one scientist not involved in the new work.
Mimic a volcano
All scientists agree that Earth gets
warmer and colder across the eons. A delicate and ever-changing balance between solar radiation, cloud cover, and heat-trapping
greenhouse gases controls long-term swings from ice ages to warmer conditions like today. |
LINK TO I.A.A. |
|
An illustration of the ring of particles or spacecraft casting a shadow on equatorial Earth |
Those who are often
called experts admit to glaring gaps in their knowledge of how all this works. A study last month revealed that scientists can't pin down one of the most critical keys: how much sunlight our planet absorbs versus how much is reflected
back into space.
Nonetheless, most scientists
think our climate has warmed significantly over the past century and will grow warmer over the next hundred years. Various studies claim the planet is destined to warm by anywhere from 1 to 20 degrees Fahrenheit over the next few centuries. Seas will rise dramatically, the scenario goes, inundating coastal cities. But another group of scientists argue that the temperature data supporting
a warming planet is not firm and that projections, based on computer modeling, might be wildly off the mark.
Either way, perhaps
our fate is more in our hands than we might have imagined.
"Reducing solar insolation
by 1.6 percent should overcome a 1.75 K [3 degrees Fahrenheit] temperature rise," contends a group led by Jerome Pearson,
president of Star Technology and Research, Inc. "This might be accomplished by a variety of terrestrial or space systems."
The power of scattering
sunlight has been illustrated naturally, the scientists note. Volcanic eruptions, such as that of Mt. Pinatubo in 1991, pumped aerosols into the atmosphere and cooled the global climate by about a degree. Other researchers have suggested such
schemes as adding metallic dust to smoke stacks, to flood the atmosphere and reflect more sunlight back into space.
In the newly outlined
approach, reflective particles might come from the mining of Earth, the Moon or asteroids. They'd be put into orbit around
the equator. Alternately, tiny micro-spacecraft could be deployed with reflective umbrellas.
A ring created by a
batch of either "shades the tropics primarily, providing maximum effectiveness in cooling the warmest parts of our planet,"
the scientists write. An early version of their idea was presented but not widely noticed in 2002.
Eccentric but reassuring
Those researchers who
don't buy the argument that global warming is occurring at any significant rate nor that humans are largely to blame may warm
up quickly to the new idea.
Benny Peiser, a social
anthropologist at Liverpool John Moores University in the UK,
tracks climate research and the resulting media coverage. He's among the small but vocal group that goes against mainstream
thought on the topic of global warming.
"I don't think that
the modest warming trend we are currently experiencing poses any significant or long-term threat," Peiser told LiveScience.
"Nevertheless, what the paper does show quite impressively is that our hyper-complex civilization is theoretically and technologically
capable of dealing with any significant climate change we may potentially face in the future."
Peiser also notes that
the Kyoto Protocol, a global agreement to reduce greenhouse gas emissions, is estimated to cost the world economy some $150 billion a year.
He also sees a broader rationale for supporting the seemingly bizarre manner of managing Earth's temperature budget.
"I believe that this
mindset, despite its apparent eccentricity, is actually rather reassuring," Peiser said. "It provides concerned people with
ample evidence of the extraordinary human ingenuity that, as so often in the past, has helped to overcome many predicaments
that were regarded as impenetrable in previous times."
He also sees an ultimate
big-picture reasoning to look favorably on the notion of controlling Earth's climate.
"Whatever the cost
and regardless of whether there is any major risk due to global warming," Peiser said, "it would appear to me that such a
space-based infrastructure will evolve sooner or later, thus forming additional stepping stones of our emerging migration
towards outer space."
Related Stories
Surprising Side Effects of Global Warming
Sea
Salt Inhibits Global Warming
University Of Manchester
02-23-2005
Scientists
at The University of Manchester are examining a novel idea for delaying the effects of climate change using a combination of clouds and sea salt.
Atmospheric
experts Professor Tom Choularton and Dr. Keith Bower, who are working with a team of leading scientists around the world on
the theory, have developed a computer simulation which shows how adding sea salt to clouds can slow global warming.
The
idea, conceived by Professor John Latham, an Emeritus Professor at the University, now based at National Centre for Atmospheric
Research in Colorado, is to use clouds as natural heat shields which when injected with salt reflect more sunlight and therefore
protect against the greenhouse effect.
Professor
Choularton, said: 'What our simulation shows is that if you artificially inject sea salt into clouds it not only increases
the amount of heat which is reflected back into space, creating a cooling effect, but it also inhibits the formation of drizzle,
which means the clouds last longer, more heat is reflected, and the cooling effect lasts longer.'
Professor
Choularton's principal role is to understand the effect artificially injecting salt will have on the clouds, in particular
whether it will cause any adverse effects. This information will then be used to plan small-scale pilot projects to see how
the clouds react in the field.
One
of the challenges the team faces is how to get salt into the clouds, in particular low level lumpy grey clouds, known as stratocumulus,
which are the only type of clouds which will produce this cooling effect.
One
idea, developed by Professor Stephen Salter of the University of Edinburgh, is to use high-frequency generators on board yachts to convert sea water into a very fine mist of
salt particles which rise up and embed themselves in the clouds.
'If
all of this is successful then it may be possible to have an operational system which over a small area of the globe would
have the effect of off-setting global warming and reducing global temperature,' says Professor Latham.
'This
would not be an ultimate solution to global warming but it would be a way of buying more time if the worst impacts of global
warming start to manifest themselves over the next couple of decades,' he added.
The
team is now hoping to gain funding to carry out pilot projects designed to test this theory.
Editor's
Note: The original news release can be found here.
This
story has been adapted from a news release issued by University Of Manchester.
Sea
salt inhibits global warming (21 Feb, 2005)
Scientists
at The University of Manchester are examining a novel idea for delaying the effects of climate change using a combination of clouds and sea salt.
Atmospheric
experts Professor Tom Choularton and Dr. Keith Bower, who are working with a team of leading scientists around the world on
the theory, have developed a computer simulation which shows how adding sea salt to clouds can slow global warming.
The
idea, conceived by Professor John Latham, an Emeritus Professor at the University, now based at National Centre for Atmospheric
Research in Colorado, is to use clouds as natural heat shields which when injected with salt reflect more sunlight and therefore
protect against the greenhouse effect.
Professor
Choularton, said: 'What our simulation shows is that if you artificially inject sea salt into clouds it not only increases
the amount of heat which is reflected back into space, creating a cooling effect, but it also inhibits the formation of drizzle,
which means the clouds last longer, more heat is reflected, and the cooling effect lasts longer.'
Professor
Choularton's principal role is to understand the effect artificially injecting salt will have on the clouds, in particular
whether it will cause any adverse effects. This information will then be used to plan small-scale pilot projects to see how
the clouds react in the field.
One
of the challenges the team faces is how to get salt into the clouds, in particular low level lumpy grey clouds, known as stratocumulus,
which are the only type of clouds which will produce this cooling effect.
One
idea, developed by Professor Stephen Salter of the University of Edinburgh, is to use high-frequency generators on board yachts to convert sea water into a very fine mist of
salt particles which rise up and embed themselves in the clouds.
'If
all of this is successful then it may be possible to have an operational system which over a small area of the globe would
have the effect of off-setting global warming and reducing global temperature,' says Professor Latham.
'This
would not be an ultimate solution to global warming but it would be a way of buying more time if the worst impacts of global
warming start to manifest themselves over the next couple of decades,' he added.
The
team is now hoping to gain funding to carry out pilot projects designed to test this theory.
For
further information please contact Simon Hunter, Media Relations Officer, on telephone: 0161 2758387
Notes
to Editors:
Professor
Choularton is Professor of Atmospheric Physics at The University of Manchester in the School of Earth, Atmospheric and Environmental Sciences.
Professor
Choularton's collaborators include Professor John Latham, National Centre for Atmospheric Research in Colorado, Professor
Stephen Salter, University of Edinburgh, Professor Mike Smith, University of Leeds and Dr Andy Jones, Hadley Centre at the
Meteorological Office.
African
Dust Storm May Redden U.S. Sunsets
By The Associated Press from
Live Science .com
posted: 24 July 2005 11:17 am ET
MIAMI (AP) -- An enormous, hazy cloud of dust from the Sahara Desert is blowing toward the southern United States,
but meteorologists do not expect much effect beyond colorful sunsets.
The leading edge of the cloud -- nearly the size of the continental United States -- should move across Florida sometime from Monday through Wednesday.
"This is not going to be a tremendous event, but it will be kind of interesting,'' said Jim Lushine, a severe weather
expert with the National Weather Service in Miami.
He said the dust could make sunrises and sunsets spectacular.
It might not have much effect on the rest of the country, said Scott Kelly, a meteorologist with the weather service
in Melbourne.
"Maybe south Texas or Mexico if that dust cloud keeps moving westward, but nothing north of Florida, unless a weather
system can dive southward and pull that air northward,'' he said.
Such dust clouds are not uncommon, especially at this time of year. They start when weather patterns called tropical
waves pick up dust from the desert in North Africa, carry it a couple of miles into the atmosphere and drift westward.
If the dust is concentrated enough, it could create some problems for people with respiratory problems, said Ken Larson,
a natural resource specialist with the Broward County Environmental Protection Department.
"If somebody is subject to a respiratory condition, if they see hazy skies,
they might want to take a little more precaution, not participate in strenuous activity and stay indoors,'' Larson said.
PDF] Why is the global warming proceeding much slower than expected L Bengtsson, E Roeckner, M Stendel - View as HTML - Cited by 29 ... BENGTSSON ET AL.: WHY IS THE GLOBAL WARMING SLOWER THAN EXPECTED? ... Doiron, CC Schnetzler, AJ Krueger, and LS
Walter, Global tracking of the SO 2 clouds from the ... J. Geophys. Res, 1999 - glwww.dmi.dk - agu.org - agu.org - adsabs.harvard.edu
Clearing smoke may trigger global warming rise
18:59 29 June 2005
NewScientist.com news service
http://www.newscientist.com/article.ns?id=dn7607
Fred Pearce
Global warming looks set to be much worse than
previously forecast, according to new research. Ironically, the crucial evidence is how little warming there has been so far.
Three top climate researchers claim that the
greenhouse gases already in the atmosphere should have warmed the world more than they have. The reason they have not, they
say, is that the warming is being masked by sun-blocking smoke, dust and other polluting particles put into the air by human
activity.
But they warn that in future this protection
will lessen due to controls on pollution. Their best guess is that, as the mask is removed, temperatures will warm by at least
6°C by 2100. That is substantially above the current predictions of 1.5 to 4.5°C.
“Such an enormous increase would be comparable
to the temperature change from the previous ice age to the present,” says one of the researchers, Meinrat Andreae of
the Max Planck Institute for Chemistry in Mainz, Germany. “It is so far outside the range covered by our experience and scientific understanding that
we cannot with any confidence predict the consequences for the Earth.”
Cool estimate
The calculations assume a doubling of greenhouse
gases such as carbon dioxide (CO2) in the atmosphere by 2100 compared to pre-industrial levels.
Andreae and his two British colleagues, Peter
Cox and Chris Jones, are leading authors from the UN’s Intergovernmental Panel on Climate Change. These new findings
are likely to be reflected in the IPCC’s next assessment of climate change science, scheduled for 2007.
The cooling effect of aerosols has been known
for some time. But, says Andreae, past assessments have underestimated its influence. Because of this, they have also underestimated
the sensitivity of the atmosphere to the warming effect of greenhouse gases.
The new modelling study finds that only high
estimates of both aerosol cooling and greenhouse warming can explain the history of global temperatures over the past 50 years.
One foot on the gas
The problem for future climate is that the cooling
aerosols only stay in the air for a few days, whereas the warming gases stick around for decades or centuries. So while the
cooling effect is unlikely to grow much, the gases will accumulate and have an ever-bigger effect on global temperature.
The world, says Andreae, is “driving the
climate with one foot on the gas and the other on the brake. When the brake comes off, it makes a hell of a difference".
The authors have added another previously unrecognised
element to the temperature forecast - the effect of all this on nature and the natural carbon cycle.
Natural ecosystems are currently absorbing up
to half of the CO2 that humans put into the atmosphere. Most climate models assume this will continue. But there is growing
evidence that from about 2050, soils and forests will stop absorbing CO2 and start releasing it instead.
The authors calculate that this switch in the
natural carbon cycle could accelerate the build-up of CO2 in the air by more than 50%, producing a total warming that “may
be as high as 10°C” by 2100.
9/11 study:
Air traffic affects climate
August 8, 2002
By Richard Stenger
(CNN) -- The
thin wisps of condensation that trail jet airliners have a significant influence on the climate, according to scientists who
studied U.S. skies during a rare interruption in national
air traffic after the September 11 terrorist attacks.
During the three-day
commercial flight hiatus, when the artificial clouds known as contrails all but disappeared, the variations in high and low
temperatures increased by 1.1 degrees Celsius (2 degrees Fahrenheit) each day, said meteorological researchers.
While the temperature
range is significant, whether the jet clouds have a net effect on global warming remains unknown.
"I think what
we've shown are that contrails are capable of affecting temperatures," said lead scientist David Travis of the University
of Wisconsin, Whitewater. "Which direction, in terms of net heating or cooling,
is still up in the air."
In many ways,
contrails behave in the same manner as cirrus clouds, thin high-altitude floaters that block out solar energy from above and
trap in heat below.
As a result,
they help reduce the daily range in daytime highs and nighttime lows. Contrails, by providing additional insulation, further
reduce the variability.
With air traffic
growing and contrails becoming more prevalent, the natural variation will further decline and could disrupt regional ecosystems,
some scientists speculate.
Certain trees,
crops and insect species depend on specific daily temperature variations for their survival.
In some ways,
contrails differ from their natural brethren. Cirrus clouds let less heat out than in overall, producing a net increase in
the Earth's temperatures, according to climate scientists. With contrail clouds, they said they are not so sure.
"Contrails are
denser and block sunlight much more than natural cirrus clouds," said Travis, who conducted the study with Andrew Carleton
of Penn State University
in University Park, Pennsylvania. They reported the findings
this week in the journal Nature.
"And contrails
are much more prevalent when the sun is out," he said. "When this is factored in, there is a possibility that they offset
global warming, and this is what we are trying to determine now."
The researchers
plan more studies to tackle that question, but they said they expect to rely on circumstantial evidence only.
"We can only
hope that the September 11 tragedy never happens again," Travis said.
Cosmic dirt makes deep climate impact Christine White August 25, 2005
The Australian
A MASSIVE 40,000 tonnes of space dust and debris rain down on Earth every year - and the particles are
big enough to affect the planet's climate.
"Cosmic dust" from a recent meteoroid explosion was studied by a team of researchers, including Andrew Klekociuk from
the Australian Antarctic Division in Kingston, Tasmania.
Published in Nature today, scientists found the dust particles from the spectacular explosion over Antarctica last September were about
1000 times bigger than previously thought. "And bigger particles have a much greater climate impact potential," Dr Klekociuk
said.
After the explosion, dust rained down on the area for several weeks. "Most of the dust would have ended up in the stratosphere
- 10km to 50km up - where it could reside for months," he said.
Researchers warn this could contribute to climate change, as dust particles can reflect sunlight, promote cloud formation
and even cause ozone depletion.
Duncan Steel, space researcher with Ball Aerospace in Canberra, said: "It's obvious that our climate is largely
controlled by the sun, but there are other off-planet factors that can affect the environment. This seems to be one of them."
The meteoroid studied by Dr Klekociuk and colleagues originally weighed about 1million kilograms, making it one of
the biggest chunks of space rock to enter Earth's atmosphere in the past decade.
When it exploded, it released a similar amount of energy to the nuclear bomb that destroyed Hiroshima.
"I can almost guarantee
that everyone has at least one tiny micrometeorite - cosmic dust particle - in their hair," Dr Steel said.
- pdf download of this paper : (http://eed.llnl.gov/cccm/pdf/Govindasamy_etal_2003.pdf)
Title: |
|
Impact of Geoengineering Schemes on the Terrestrial Biosphere |
Authors: |
|
Govindasamy, B.; Thompson, S. L.; Duffy, P. B.; Caldeira, K. G.; Delire, C. |
Affiliation: |
|
AA(Lawrence Livermore National Lab, 7000 East Ave. L-103, Livermore, CA 94550 United
States ;
Bala@llnl.gov), AB(Lawrence Livermore National Lab, 7000 East Ave. L-103, Livermore, CA 94550 United States ;
thompson59@llnl.gov), AC(Lawrence Livermore National Lab, 7000 East Ave. L-103, Livermore, CA 94550 United States
;
pduffy@llnl.gov), AD(Lawrence Livermore National Lab, 7000 East Ave. L-103, Livermore, CA 94550 United States ;
kenc@llnl.gov), AE(University of Wisconsin-Madison, 1225 W. Dayton St., Madison, WI 53706 United States ;
cldelire@facstaff.wisc.edu) |
Journal: |
|
American Geophysical Union, Fall Meeting 2002, abstract #A12A-0131 |
Publication Date: |
|
12/2002 |
Origin: |
|
AGU |
AGU Keywords: |
|
0315 Biosphere/atmosphere interactions, 1600 GLOBAL CHANGE (New category), 1615 Biogeochemical
processes (4805), 1620 Climate dynamics (3309), 3309 Climatology (1620) |
Abstract Copyright: |
|
(c) 2002: American Geophysical Union |
Bibliographic Code: |
|
2002AGUFM.A12A0131G |
AbstractClimate stabilization via "Geoengineering" schemes seek to mitigate climate change
due to increased greenhouse gases by compensating reduction in solar radiation incident on earth's surface. Though the spatial
and temporal pattern of radiative forcing from greenhouse gases differs from that of sunlight, it was shown in recent studies
that these schemes would largely mitigate regional or seasonal climate change for a doubling and quadrupling of the atmospheric
CO2 content. In this study, we address the impact of these climate stabilization schemes on terrestrial biosphere
using equilibrium simulations from a coupled atmosphere-terrestrial biosphere model (CCM3-IBIS). Geoengineering schemes would
tend to limit changes in vegetation distribution brought on by climate change, but would not prevent CO2 -induced
changes in NPP or biomass; indeed, if CO2 fertilization is significant, then a climate-stabilized world could have
higher net primary productivity NPP than our current world. Nevertheless, there are many reasons why geoengineering is
not a preferred option for climate stabilization.Impact of Geoengineering Schemes on the Terrestrial Biosphere
Bibtex entry for this abstract Preferred format for this abstract (see Preferences)
Artificial
Clouds:
New Ruskin College.com
What site did Yahoo! pick as number one for “Artificial Clouds” and “Global
Warming”? 1. The Gorbachev-Bush Artificial Clouds Letters . ... www.newruskincollege.com/
- 194k - Cached - Similar pages |
On modification of global warming by sulfate aerosols JFB Mitchell, TC Johns - J. Climate, 1997 - ams.allenpress.com ... On Modification of Global Warming by Sulfate
Aerosols. ... gases tend to warm climate by reducing the efficiency with which longwave radiation escapes to space. ... Cited by 105 - Web Search - ams.allenpress.com - adsabs.harvard.edu
Potential climate impact of Mount Pinatubo eruption J HANSEN, A LACIS, R RUEDY, M SATO - Geophysical Research Letters, 1992 - agu.org ... NASA Goddard Space Flight Center Goddard Institute
for Space Studies, New York. ... model forecasts a dramatic but temporary break in recent
global warming trends. ... Cited by 53 - Cached - Web Search - adsabs.harvard.edu - csa.com
PDF]
Global Warming/ Cooling Effects of Atmospheric Aerosols
File Format: PDF/Adobe Acrobat - View as HTML The former is named as Artificial Clouds Experimental System (ACES) and has ... of global
warming. Furthermore, the interaction between these substances has ... aerosol.energy.kyoto-u.ac.jp/
~tokutei/03ResearchReport/English/A04E.pdf - Similar pages |
A04 G Warming, C Effects - aerosol.energy.kyoto-u.ac.jp Page 1. A04 Global Warming/ Cooling Effects ... Teine in Hokkaido, Japan. The former is named as Artificial Clouds Experimental
System (ACES) and has 430m depth. ... View as HTML - Web Search - aerosol.energy.kyoto-u.ac.jp
Development of environmentally-friendly technologies
and configurations for subsonic jet transports JP
Fielding, H Smith - 23 rd International Congress of Aeronautical Sciences, 2002 - lu.fme.vutbr.cz ... carbon dioxide and 3.5% of all human- produced global warming effects ... Aircraft
trail artificial clouds behind them thus artificially increasing cloud cover and ... View as HTML - Web Search - csa.com
911 study. Air traffic affects climate
... when the artificial clouds known as contrails all but disappeared, ...
whether the jet clouds have a net effect on global warming remains unknown. ... www.airapparent.ca/library/full_text/911_study.htm
- 12k - Cached - Similar pages |
Optical observations of artificial clouds in the upper
atmosphere GP Milinevskii, IA Romanovskii, VV Alpatov, IE … - Kosmicheskie Issledovaniia,
1993 - adsabs.harvard.edu Title:
Optical observations of artificial clouds in the upper atmosphere Authors: Milinevskii, GP; Romanovskii, Iu. A.; Alpatov,
VV; Belikov, Iu. ... Web Search - csa.com
Chemistry of artificial gaseous clouds in the earth's
upper atmosphere IM Gershenzon, VM Grigor'eva, S Maksiutov…
- IN: Physics of the upper atmosphere (A91-29876 11-46). …, 1990 - adsabs.harvard.edu ... Publication Date: 00/1990 Category: Geophysics Origin: STI NASA/STI Keywords: ARTIFICIAL CLOUDS, ATMOSPHERIC CHEMISTRY,
ATMOSPHERIC MODELS, UPPER ATMOSPHERE ... Web Search
Utah State University East Coast sky watchers caught a glimpse of artificial clouds created Sunday night
as part of a research project involving Utah State University’s Space ... utahstatetoday.usu.edu/archives/
july2003/07-04-03/inthenews-07-04-03.cfm - 16k - Cached - Similar pages
Cool It!!
... suggests several methods for combating the effects of global warming by
... jet engines to produce a layer of thin artificial clouds in the stratosphere ... www.meteor.iastate.edu/gccourse/forcing/coolit.html - 2k - Cached - Similar pages |
Basic formulas for the determination of the altitude
of artificial clouds H DEBEHOGNE, VAN HEMELRIJCK - Academie Royale de Belgique, Classe des Sciences, Bulletin,
1972 - csa.com Basic formulas
for the determination of the altitude of artificial clouds. H DEBEHOGNE, VAN HEMELRIJCK Academie Royale de Belgique ... Web Search
Determination of the optical thickness of artificial
clouds in the upper atmosphere IV Moskalenko, AG Kheinlo, DA Shcheglov, AB … - Kosmicheskie Issledovaniia,
1990 - adsabs.harvard.edu Title:
Determination of the optical thickness of artificial clouds in the upper atmosphere Authors: Moskalenko, I. V.; Kheinlo,
A. G.; Shcheglov, D. A ... Web Search - csa.com
Base formulae for the determination of the altitude
of artificial clouds(Altitude calculation for … H DEBEHOGNE, E VANHEMELRIJCK - 1972 - csa.com Base formulae for the determination of the altitude
of artificial clouds(Altitude calculation for artificial methane and oxygen clouds in upper atmosphere). ... Web Search
A method for the analysis of artificial clouds in the
upper atmosphere J NAKAMURA, T MATSUOKA, H KIMURA - Report of Ionosphere and Space Research in Japan,
1972 - csa.com A method for
the analysis of artificial clouds in the upper atmosphere. J NAKAMURA, T MATSUOKA, H KIMURA Report of Ionosphere and ... Web Search
Turbulent diffusion, dissipation, and winds from calibrated
photographs of artificial clouds CA Trowbridge - 1983 - adsabs.harvard.edu Title: Turbulent diffusion, dissipation, and winds from calibrated photographs
of artificial clouds Authors: Trowbridge, C. A. Affiliation: Photometrics, Inc ... Web Search
Visual performance with simulated flarelight in artificial
clouds Final report, Feb.- Aug. 1969( … PK ASE, RL HILGENDORF, S KATZ,
E RAISEN - 1970 - csa.com Visual
performance with simulated flarelight in artificial clouds Final report, Feb.- Aug. 1969(Laboratory procedure for measuring
...
MEASUREMENT OF UPPER-WIND VELOCITIES BY OBSERVATIONS OF ARTIFICIAL ... The American Meteorological Society (AMS), publishes
seven well-respected scientific journals and an abstract journal, in addition to the Bulletin, ... ams.allenpress.com/.../?request=get-abstract& doi=10.1175%2F1520-0493(1925)53%3C165b:MOUVBO%3E2.0.CO%3B2
- Similar pages
Optical tomography of artificial formations in near-earth space Publication Date: 02/1993 Category:
Optics Origin: STI NASA/STI Keywords: ARTIFICIAL CLOUDS, INTERPLANETARY SPACE, LIGHT SCATTERING, RECONSTRUCTION, ... adsabs.harvard.edu/abs/1993CosRe..31..121A - Similar pages
Sulfur
Aerosols:
… climate change simulations with a coupled atmosphere-ocean
GCM including the tropospheric sulfur … E Roeckner, L Bengtsson, J Feichter, J Lelieveld, … - Journal of Climate, 1999
- ams.allenpress.com ... the coupled model using prescribed sulfur emissions of ... predominantly governed by the amount
of global warming. ... With aerosols included, the changes are broadly ... Cited by 222 - Web Search - ams.allenpress.com - adsabs.harvard.edu - csa.com
Causes of twentieth-century temperature change near the Earth's
surface SFB Tett, P Stott, MR Allen, WJ Ingram, JFB … - Nature, 1999 - nature.com ... & Johns, TC On modification of global
warming by sulfate ... surface
temperature, greenhouse gases, and aerosols: Models and ... model of the tropospheric sulfur cycle ... Cited by 96 - Web Search - nature.com - csa.com
Why is the global warming proceeding much slower than expected? L Bengtsson, E Roeckner, M Stendel - Journal of Geophysical Research, 1999 - glwww.dmi.dk ... instruments does not indicate any global
warming during the ... dis-
tribution of sulfate aerosols and then ... have integrated the full anthropogenic sulfur cycle in ... Cited by 37 - View as HTML - agu.org - adsabs.harvard.edu - csa.com
Quantifying the uncertainty in forecasts of anthropogenic climate
change MR Allen, P Stott, JFB Mitchell, R Schnur, TL … - Nature, 2000 - nature.com ... with a coupled atmosphere-ocean gcm including the tropospheric sulfur cycle ... Mitchell, JFB & Johns, TC On modification
of global warming by sulphate
aerosols. ... Cited by 69 - Web Search - adsabs.harvard.edu - ncbi.nlm.nih.gov - csa.com - all 6 versions »
Interpretation of high projections for global-mean warming TML Wigley, SCB Raper, J Reilly, PH Stone, CE
… - Science, 2001 - stephenschneider.stanford.edu ... scenarios [particularly
emissions of sulfur dioxide (SO 2 ...
pdfs for projected global warming
requires knowledge ... forcing due to aerosols,
particularly sulfate ... Cited by 104 - Web Search - op.gfz-potsdam.de - nome.colorado.edu - courses.eas.ualberta.ca - all 11 versions »
Production of atmospheric sulfur by oceanic plankton: biogeochemical, ecological and R Simo - TRENDS in Ecology & Evolution, 2001 - iq.usp.br ... Oxidation of DMS in the marine atmosphere produces sulfur
AEROSOLS that, either directly or by acting as cloud condensation nuclei,
scatter solar radiation ... Cited by 20 - View as HTML - Web Search - ncbi.nlm.nih.gov
… black carbon and organic matter, possibly the most effective
method of slowing global warming MZ Jacobson - J. Geophys. Res, 2002 - stanford.edu ... BC + OM will not only slow global
warming but also improve human health. I NDEX T ERMS : 0305 Atmospheric
Composition and Structure: Aerosols and particles ... Cited by 33 - View as HTML - Web Search - airimpacts.org - adsabs.harvard.edu
Global warming feedbacks on terrestrial carbon uptake under the Intergovernmental Panel on Climate … F Joos, IC Prentice, S Sitch, R Meyer, G Hooss, GK … - Global Biogeochemical
Cycles, 2001 - nccr-climate.unibe.ch ... 2 JOOS ET AL.: GLOBAL WARMING FEEDBACKS ON TERRESTRIAL CARBON ... it is assumed that sulfur emission controls ... Radiative forcing by sulfate aerosols is estimated to ...Cited by 22 - View as HTML - Web Search - quercus.igpp.ucla.edu - climate.unibe.ch - adsabs.harvard.edu - all 5 versions »
On modification of global warming by sulfate aerosols JFB Mitchell, TC Johns - J. Climate, 1997 - ams.allenpress.com ... On Modification of Global Warming by Sulfate Aerosols. ... also leads to the release of sulfur, which oxidizes and
forms hydrated sulfate aerosols (see, eg ... Cited by 105 - Web Search - ams.allenpress.com - adsabs.harvard.edu
NASA : Office of Logic Design: Digital Engineering Institute (DEI) - References: General Aerospace Acta Astronautica Vol.
11, No.2, pp. 149-153, 1984, Abstract ... This New Ocean The Story of the First Space Age William E. Burroughs © 1998 by William
E. Burroughs ISBN 0-375-75485-7 Contents The New Ocean: Bird Envy; Rocket Science; Gravity's Archers; Missiles for America;
The Other World Series; To Race Across the Sky; War and Peace in the Third Dimension; The Greatest Show on Earth; A Bridge
for Galileo; To Hit a Moving Target The Infinite Voyage: From the Earth to the Moon; Destination Mars; A Grand Tour: The Majestic
Adventure; The Roaring Eighties; Downsizing Infinity; The Rings of Earth; The Second Space Age.
copyright 2010 NewRuskinCollege
|