CCNet 105/2003 - 13 November 2003

Imagine you're in California. It's July, the middle of summer. The sun rises early;
bright rays warm the ground. It's a great day to be outside. Then, suddenly, it begins
to snow--not just a little flurry, but a swirling blizzard that doesn't stop for two
weeks. That's what forecasters call unseasonal weather. It sounds incredible, but
"something like that just happened on the sun," says David Hathaway, a solar physicist
at NASA's Marshall Space Flight Center.
     --Science@NASA, 12 November 2003

These [sun] spots are still active. Explosions from their vicinity have been hurling
clouds of gas over the sun's limb in recent days, e.g., on Nov. 11th and Nov. 12th.
The sun's 27-day rotation will soon carry the pair around to the Earth-facing side of
the sun. So get ready for more solar activity.
    --Space Weather News, 12 November 2003

    Science@NASA, 12 November 2003

    Space Weather News for Nov. 12, 2003


    Tech Central Station, 12 November 2003

    The Guardian, 13 November 2003

    BBC News Online, 13 November 2003

    Eurekalert, 11 November 2003


    The Scotsman, 13 November 2003

    San Diego Union-Tribune, 12 November 2003

     The International Herald Tribune, 13 November 2003

     Jeremie Vaubaillon <>



Science@NASA, 12 November 2003

Solar maximum is years past, yet the sun has been remarkably active lately. Is the sunspot cycle broken?

November 12, 2003:  Imagine you're in California. It's July, the middle of summer. The sun rises early; bright rays warm the ground. It's a great day to be outside. Then, suddenly, it begins to snow--not just a little flurry, but a swirling blizzard that doesn't stop for two weeks.
That's what forecasters call unseasonal weather.

It sounds incredible, but "something like that just happened on the sun," says David Hathaway, a solar physicist at NASA's Marshall Space Flight Center.

Only a few weeks ago solar activity was low. The face of the sun was nearly blank--"very few sunspots," says Hathaway--and space weather near Earth was mild. "Mild is just what we expect at this point in the 11-year solar cycle," he explains. "The most recent maximum was in 2001, and solar activity has been declining ever since."

Then, suddenly, in late October the sun began to behave strangely. Three giant sunspots appeared, each one larger than the planet Jupiter. In California where smoke from wildfires dimmed the sun enough to look straight at it, casual sky watchers were startled by the huge blotches on the sun. One of them, named "sunspot 486," was the biggest in 13 years.

Sunspots cause solar flares and, usually, the biggest flares come from the biggest spots. The three giant sunspots unleashed eleven X-class flares in only fourteen days--equaling the total number observed during the previous twelve months. "This was a big surprise," says Hathaway.
The effects on Earth were many: Radio blackouts disrupted communications. Solar protons penetrated Earth's upper atmosphere, exposing astronauts and some air travelers to radiation doses equal to a medical chest X-ray. Auroras appeared all over the world--in Florida, Texas, Australia and many other places where they are seldom seen.

Researchers rank solar flares according to their x-ray power output. C-flares are the weakest. M-flares are middling-strong. X-flares are the most powerful. Each category has subdivisions: e.g., X1, X2, X3 and so on. A typical X-flare registers X1 or X2. On Nov. 4th, sunspot 486 unleashed an X28 flare--the most powerful ever recorded.

"In 1989 a flare about half that strong caused a widespread power blackout in Quebec," recalls Hathaway. Last week's blast was aimed away from Earth, so its effects on our planet were slight--a bit of good luck.

All this happened two years after solar maximum, which raises a question: is something wrong with the solar cycle? Is the sun going haywire?

"Nothing's wrong," reassures Hathaway. The sun isn't about to explode, nor is the sunspot cycle broken. "These latest sunspots were whoppers," he allows, "but sunspot counts averaged over many weeks are still declining as predicted. We're still on course for a solar minimum in 2006."
Indeed, it's possible that what we've just experienced is a normal part of the solar cycle, speculates Hathaway. "There's a curious tendency for the biggest flares to occur after solar maximum--on the downslope toward solar minimum. This has happened during two of the last three solar cycles." The plot below illustrates his point.

Consider the year 1984, says Hathaway. Sunspot counts were plunging, and the sun was rapidly approaching the 1985-86 solar minimum. Suddenly a giant sunspot appeared, Jupiter-sized like sunspot 486, and unleashed two dozen M-flares and three X-flares, including a remarkable flare registering X13. People then probably wondered too if the solar cycle was broken.
"It's hard to be sure what's normal and what's not," notes Hathaway. "Astronomers have been observing x-rays from the sun for only 35 years--or three solar cycles. We can't draw good statistical conclusions from so few data."

One thing is certain, though: flurries of solar activity can happen at any time. The next time, says Hathaway, could be just a week or so away.

Sunspot 486 and its companions are on the far side of the sun now, carried around by the sun's 27-day rotation. "We suspect they're still active," says Hathaway, because the Solar and Heliospheric Observatory--a sun-watching satellite--has photographed clouds of gas being thrown over the sun's limb by unseen explosions. Unless these sunspots dissipate, which could happen, they will reappear on the Earth-facing side of the sun beginning as early as Nov. 14th.
And then...? No one knows. "We might get some more unseasonal space weather," says Hathaway. But this time he won't be surprised.


Space Weather News for Nov. 12, 2003

FAR SIDE SUNSPOTS: Using a technique called helioseismic holography, astronomers can do
something amazing: look through the sun to find sunspots on the far side of our star. On
Nov. 11th their holographic maps revealed giant sunspots 486 and 488--the same active
regions that caused so much intense space weather a few weeks ago.

These spots are still active. Explosions from their vicinity have been hurling clouds of
gas over the sun's limb in recent days, e.g., on Nov. 11th and Nov. 12th. The sun's 27-day
rotation will soon carry the pair around to the Earth-facing side of the sun. So get ready
for more solar activity.


By Tariq Malik
Europe's Mars Express spacecraft has overcome the effects of last week's solar flares, which temporarily knocked out navigation equipment aboard the orbiter while leaving the mission's Beagle 2 lander unscathed.

Researchers with the European Space Agency's (ESA) Mars Express mission said their spacecraft is in good health after solar storms blinded the orbiter's two star trackers for up to 15 hours. Mission controllers said both instruments, which trackers are crucial to keeping Mars Express oriented properly, are now working properly and there appears to be no long-term damage. The flares also delayed a scheduled Beagle 2 checkout procedure, but caused no ill effects otherwise.

"The Beagle 2 is designed to be radiation hard, but of course the mission manager will not be happy until we turn [the lander] back on in a week or two," said Mark Sims, referring to himself during a mission update Tuesday morning. Sims actually is the Beagle 2 mission manager. 

Sims and other ESA officials discussed the status of Mars Express and Beagle 2 during the mission update, which was held in London, England. The mission is currently six weeks away from its Dec. 25 arrival at the red planet, which the Mars Express orbiter will begin circling as the lander plummets toward the surface.

John Reddie, ESA's Mars Express flight director, said engineers are still working to solve a power problem that struck the orbiter in July. That affliction resulted in a 30 percent drop in the craft's power generation.

"The situation is the same as it was, but there has been no degradation either," Reddie said. While engineers are working to remedy the problem, should it persist up to Mars Express' red planet arrival the spacecraft will still be able to perform up to 85 percent of its original mission, he added. Ground controllers may also put the orbiter in a safe mode during periods of power loss such as eclipse, when Mars blocks sunlight from reaching the probe's solar panels.


Tech Central Station, 12 November 2003

By Sallie Baliunas
The Sun is the origin of deadly hazards in near space, which begins approximately 60 miles above earth's surface. An extreme flare that erupted from the sun on November 4 showed that the Sun's ferocity knows few limits. This extraordinarily powerful flare proved how difficult it is to predict flare hazards.

Humans have threaded low-earth orbit with electronic equipment used for navigation, communication and science aboard satellites. The gear can be damaged by bursts of swift particles ejected from the sun during a flare.

Flares occur over relatively small regions on the sun, and sometimes burst in the direction of the earth. When they do, their fast-moving protons, electrons, and nuclei of heavy atoms bombard the earth's environment. The charged particles may smash into the earth's magnetic field, releasing energy that temporarily excites the air's oxygen atoms. The atoms quickly emit the energy, often as visible greenish or reddish light seen shaped as shimmery curtains, called aurorae, washing across the night sky.

The Nov. 4 flare was of the highest energy class known -- the X-class -- and was off-scale compared to flares recorded systematically by satellite observations since the 1970s. The flare barely touched the earth because the magnetically disturbed area had been carried away from direct line of sight to the earth by the sun's spin. Still, the ensuing aurorae were spectacular, and spacecraft measurements observed the might of the flare. The flare's offset punch perhaps meant sparing some spacecraft electronics.

The sun has exhibited surprising flare activity this year. In general flares tend to occur at times when sunspots appear in the greatest number -- that is, when the sun is most heavily covered by intense regions of intense magnetic field. The sunspot cycle brings high magnetism and the possibility for flares roughly every 11 years. The cycle last peaked in 2000-2001, and the number of sunspots has been dropping to the cycle's expected low around 2005. Despite the low number of sunspots, some that have appeared have been unusually large. There is no good explanation why large spots have been recently appearing.

The unusual Nov. 4 flare probably ranks with a few great flares of the past for which satellite monitoring was unavailable, but whose strengths can be inferred from supporting observations.

On the afternoon of Thursday, Sept. 1, 1859, Richard Carrington and Richard Hodgson independently observed what is thought to be the first recorded flare in visible light. Carrington, observing the projected image of the sun, saw "a ray of light" whose "brilliancy was fully equal to that of direct Sun-light" that persisted for about five minutes. Some 17 hours later the plasma bombarded the earth so violently that aurorae were seen over much of the Northern Hemisphere, even as far south as Havana and the region of Mahastra, India, according to D. Kimball of the University of Alaska who compiled the 1859 aurora information in 1960. The ejected material had to be speeding at approximately 5 million miles per hour to cross the 93 million miles from the sun to the earth in so brief a time.

Because satellites have been destroyed during solar particle eruptions, satellites are now built to withstand the hardest-hitting known flares, with excess margin for the super events. As humans travel to the moon or Mars, they will also need to be protected from powerful flares.

Now that societies of earth have crossed the threshold of space they will have to comprehend the bizarre and dangerous environment of space. In this next phase of humankind, the cosmos will remain entirely unchanged but humans will be irrevocably altered by our experience. Knowledge of solar hazards must be advanced because they are of the first magnitude of importance among near-space hazards.

Copyright 2003, Tech Central Station


The Guardian, 13 November 2003,12977,1083410,00.html

Ian Sample

Just as scientists thought they had nailed down the answer, the debate has been reopened. A team of scientists claims the widely accepted theory that the extinction was triggered by a huge asteroid thumping into Mexico 65m years ago, cannot be true.

Evidence that a giant asteroid impact was the cause of the dinosaurs' demise first emerged in the 1980s. Scientists analysing ancient soils in Italy found that layers of clay from the end of the Cretaceous period, the time the dinosaurs vanished, were unusually rich in a heavy metal called iridium. Later evidence of the layer was found in other countries, including Denmark and New Zealand. The most likely cause was believed to be an extraterrestrial rock that struck Earth and showered iridium across the continents. Such an impact would have had a devastating affect on life, as hot rocks fell from the skies and dust shrouded the sun.

The theory gained credibility a decade ago when scientists declared they had found the smoking gun for the impact. A crater more than 100km across, that seemed to date back to the end of the Cretaceous period, was discovered near a village called Chicxulub on the Yucatan peninsula.

But according to Gerta Keller, a geologist at Princeton University, the Chicxulub crater is not linked.

Keller's team analysed rock which had melted in the intense heat of the impact, been thrown into the stratosphere and scattered far and wide. They found the oldest pieces, which have the same chemical composition as molten rock in the crater, were formed some 300,000 years before the dinosaurs became extinct. Samples from the crater back up the idea that dinosaur life existed long after the impact at Chicxulub, says Keller.

"What this means is that Chicxulub is not the smoking gun that caused the extinction. What really killed the dinosaurs must have been another impact," she says.

And so the search for the real smoking gun is on again. If, of course, an asteroid was actually responsible.

Guardian Unlimited Guardian Newspapers Limited 2003


BBC News Online, 13 November 2003
Alaska's native horse was killed off by food shortages caused by climate change - not human hunters, scientists say.

Researchers found the horses shrank in size before their extinction 12,500 years ago, which fits with the theory that they didn't have enough to eat.

Humans were unlikely to have had a hand in the horses' demise, they claim, because fossil records show man had hardly arrived on the scene by then.

The research is published in the scientific journal, Nature.

Mass extinction

Until about 20,000 to 10,000 years ago the Mammoth Steppe in Alaska contained a rich panoply of large mammals.

While London and New York lay submerged in glacial ice, the Mammoth Steppe provided a cold grassy haven to woolly mammoths, lions, bison, sabre tooth tigers - and the Alaskan horse.

Then a catastrophic thing happened. In a 10,000-year period, 70% of North America's large mammals died. Something killed those warm blooded giants, although quite what - or who - remains a matter for discussion.

There are two main suspects: our own species, Homo sapiens, or climate - or perhaps a mixture of both.

Around 12,000 years ago human migrants - known as the Clovis people - entered the New World across a land bridge from Asia.

These people are often implicated in the late Pleistocene extinction, and indeed fossil records prove they did hunt some of the animals that died out - like mammoths.

Climate change

But many experts believe climate change was the biggest culprit.

At the end of the ice-age the environment in North America changed dramatically. It got warmer - and wetter. The cold dry grassland morphed into tundra, which is largely characterised by unpalatable plants.

Large mammals like the horse - which needs a great bulk of food and has a slow breeding cycle - suffer the most from such changes.

"Horses are almost obligatory grazers," wrote Professor Dale Guthrie, from the University of Alaska, Fairbanks. "And these northern horses appear to have been the most specialized grassland-dependent component of the large mammal fauna."

Shrinking bones

In an attempt to find out what happened to the Alaskan horse, Professor Guthrie looked at how the size of their foreleg bones changed over time.

He radiocarbon-dated a series of fossilized bones, from as far back as 27,000 years.

He noticed that as time progressed the bones became smaller - in other words, the horses shrank before they went extinct.

The timing of this reduction in size coincides with the decline of grassland, which suggests the horses were suffering from a shortage of food.

Professor Guthrie believes this shrinkage, along with the date of the horses' disappearance, exonerates man.

After all, evidence for the first human settlement can be dated to 12,000 years ago - a long time after the horses' went extinct.

"There is a hiatus of over 500 radiocarbon years between the last dated Alaskan horses and the earliest undisputed human artefacts," wrote Professor Guthrie.

"Even if we allow that human hunters may have been present in Alaska at levels below archaeological visibility when horses became extinct, the idea that such a low density of hunters could have caused horse extinction requires an unlikely scale of overkill performance."

Copyright 2003, BBC

Eurekalert, 11 November 2003

Contact: Krishna Ramanujan
NASA/Goddard Space Flight Center--EOS Project Science Office

Arctic and Antarctic sea ice marching to different drivers

A 30-year satellite record of sea ice in the two polar regions reveals that while the Northern Hemisphere Arctic ice has melted, Southern Hemisphere Antarctic ice has actually increased in more recent years. However, due to dramatic losses of Antarctic sea ice between 1973 and 1977, sea ice in both hemispheres has shrunk on average when examined over the 30-year time frame.
This study presents the longest continuous record of sea ice for both hemispheres based primarily on satellites, and the longer reading already begins to highlight some new information about sea ice trends over time, like the fact that more recently the Arctic has been losing ice at a faster rate.

"If you compare the rate of loss in the Arctic for the last two decades, it is 20 percent greater than the rate of loss over the last three decades," said Don Cavalieri, lead author of the study, and a senior researcher at NASA's Goddard Space Flight Center. The study appeared in a recent issue of Geophysical Research Letters.

Over 30 years, from 1972 to 2002, the Arctic sea ice cover decreased per decade by roughly the size of the state of Arizona, some 300,000 square kilometers (almost 116,000 square miles) per decade. However, between 1979 and 2002 the sea ice area shrunk by the greater rate of 360,000 square kilometers (139,000 square miles) per decade.

The greater rate of sea ice loss in the Arctic may be due to a general warming trend in the Arctic as well as the influence of long-term oscillations or other changes in atmospheric pressure systems, which could pull in more warm air from the south.

In contrast, there was a dramatic loss of Antarctic sea ice cover from 1973 to 1977, and since then the ice has gradually spread in area.

"The increase has been slow enough that it does not totally wipe out the earlier decreases," said Claire Parkinson, senior researcher at NASA's Goddard Space Flight Center, and a co-author of the paper. Another co-author is Konstantin Y. Vinnikov, of the department of meteorology at the University of Maryland, College Park.

Overall, from 1972 to 2002, the Antarctic ice declined on average by 150,000 square kilometers per decade (almost 58,000 square miles).

In the Antarctic, the gradual advance of ice from the late 1970s may be related to long-term atmospheric oscillations in the Southern Hemisphere resulting in stronger westerly winds and cooler temperatures.

"Trying to explain why these things happen becomes tricky," said Parkinson. "The temperature connection where warmer temperatures lead to greater melt is reasonably direct, but far from the complete story. Winds and waves move ice around, and consequently the ice can move to places where it is warm enough that it wouldn't have formed."

While the study represents the longest continuous record comparing the two polar regions, there was a major gap in the satellite sea ice data between early 1977 and late 1978. This gap was filled by maps of sea ice created from ship and other reports in polar areas and conveyed to the National Ice Center.

The study uses satellite data from NASA's Nimbus 5 Electrically Scanning Microwave Radiometer (ESMR), NASA's Nimbus 7 Scanning Multichannel Microwave Radiometer (SMMR), and the Defense Meteorological Satellite Program Special Sensor Microwave Imagers (SSMIs). The Nimbus 5 ESMR data covered from December 1972 to March 1977, with the Nimbus 7 SMMR combined with the Defense Program's SSMIs picking up data from October 1978 to December 2002. For the year and a half in between 1977 and 1978, the researchers used data and maps from the National Ice Center.

"The National Ice Center all along created operational maps of sea ice cover to help ships in the region trying to navigate around or through the ice," Parkinson said. These maps, while not as comprehensive as satellite data, had to be created every week, using the best data available at the time. The researchers figured it was the most accurate data to bridge the gap between the satellite records. Previously, NASA scientists had blended the SMMR and SSMI data sets together to generate a 20-year time series of sea ice extents from 1979 to 1998.

By having a 30 year record, the researchers have a much longer baseline to see the trends in both the Arctic and the Antarctic, and they can see seemingly unusual events like the rapid loss of ice in Antarctica in the mid-70s.

"It seems the two regions are responding to different hemispheric variations," said Cavalieri. "What remains is to sift out and understand how these variations are driving the sea ice in each hemisphere."

====== SCARES, SCARES, AND MORE SCARES ============


The Scotsman, 13 November 2003

By John von Radowitz, Science Correspondent, PA News

Britain could have a climate like Iceland's within the next 100 years, a scientist warns today.

Ironically, the change would come about as a result of global warming.

Speaking on a television programme today, scientists will voice their fears about the Gulf Stream being suddenly cut off.

They say the process may have already begun because of changes caused by global warming.

The Gulf Stream carries ocean heat past Britain's shores, ensuring that the climate stays mild.

If it was not there, temperatures in the UK would plunge.

The Iceland Britain scenario is investigated on the Big Chill, broadcast on BBC 2's Horizon programme tonight.

Expert Terry Joyce, from Woods Hole Oceanographic Institute in the US says: "The likelihood of having an abrupt change is increasing because global warming is moving us closer and closer to the brink. We don't know where it is, but we know one thing, we're moving closer to the edge.

"And so I'd say that within the next 100 years it's very likely, in other words a 50% probability that this might happen."

The change would come almost out of the blue.

"It will be quick, and suddenly one decade we're warm, and the next decade we're in the coldest winter we've experienced in the last 100 years, but we're in it for 100 years," he says.

Dr Bill Turrell, from the Fisheries Research Service in Aberdeen, has been measuring the salt-content of the Gulf Stream current flowing north of Scotland.

If salinity is dropping, it is a sign that the driving force behind the Gulf Stream is weakening.

Global warming threatens the gulf stream because it is predicted to produce more fresh water, which would dilute the salty waters of the current. This in turn would stop it sinking, and if this happened the heat it carries would be cut off.

Dr Turrell's measurements show that the Gulf Stream's salinity is indeed dropping.

"It's the most fundamental change I've observed in my career," he tells the programme. "We were really worried when we saw these results. We'd never seen a change like this before.

"These changes are fundamental; they are substantial; They are going to impact our climate and the climate our children have to live in." 

Copyright 2003, The Scotsman


San Diego Union-Tribune, 12 November 2003

A geologist thinks methane releases nearly caused the end of Earth; could it happen again?

By Richard A. Lovett

Two hundred fifty million years ago, at the end of a geological epoch known as the Permian, the Earth went through an environmental upheaval so severe that life nearly ended. At least 90 percent of the planet's plant and animal species were wiped out - and some estimates put the figure much higher.

"It was the mother of all extinctions," says Gregory Retallack, a geologist from the University of Oregon who has traced the event across narrow bands of rock in places as remote as South Africa and Antarctica.

Scientists have long been puzzled by what might have caused such a massive die-off, posing theories that range from catastrophic volcanism to a wallop from a large asteroid, similar to the one believed to have wiped out the dinosaurs 185 million years later.

But, in a study published in the September issue of the Geological Society of America Bulletin, Retallack proposed a new explanation: The denizens of the Permian died of altitude sickness caused by a drastic decline in atmospheric oxygen.

That's right: altitude sickness - the problem that leaves you gasping for breath in the thin air of Denver or Mexico City. At higher elevations it produces headaches, nausea, dizziness, and, if you go high enough, deadly fluid buildups in the lungs and brain.

Retallack bases his theory in part on the fact that of the few land animals that survived, one of the most abundant was a reptile called Lystrosaurus. A burrowing creature, Lystrosaurus had a barrel chest, short, squat legs and a flat face. These characteristics helped it live underground, but Retallack says that they would also aid survival in a world of reduced oxygen. The animals' barrel chests allowed strong chest muscles for powerful breathing. Short limbs reduced the workload on the heart as it pumped oxygenated blood to the muscles. A flat face facilitated rapid, unobstructed breathing. In addition, Lystrosaurus' nasal passages were designed like those of humans, allowing the animals to breathe and chew at the same time.

Other Permian reptiles were like modern-day alligators, which must hold their breaths while eating, a disadvantage if oxygen is in short supply.

Methane key

Lystrosaurus isn't the only Permian survivor that showed traits that would be important in a reduced-oxygen environment. In the ocean, surviving mollusks were muscular varieties that could pump large volumes of seawater through their bodies for the most efficient extraction of oxygen. On land, surviving plants tended to be those that grew in dry, well-aerated soils, where oxygen could easily get to their roots.

All these factors help build a case that the ability to live on reduced oxygen was important for surviving the Permian extinction. But the theory would be little more than an exercise in speculation if there were no way to explain what happened to all that oxygen.

Retallack believes the answer can be found in vast, seabed reservoirs of methane, a chemical comprised of a single carbon atom linked to four atoms of hydrogen.

On the seabed, methane is continuously formed by the action of bacteria on buried organic matter. Methane is a gas, but instead of percolating to the surface, it remains beneath the ocean, trapped by the pressure of the overlying water in a form called methane hydrates.

These hydrates can lie dormant for millions of years, until something disturbs them and frees the methane to bubble to the surface and enter the atmosphere.

"Several things could have done the trick," Retallack says. "A meteorite impact or volcanic eruption right into a big methane reservoir, a volcanic eruption, volcanic gases warming the Earth, a submarine landslide triggered by an earthquake. Or, all of these could have happened together."

Once it reached the atmosphere, the methane would have reacted with oxygen to form water and carbon dioxide. Plants would then have used the carbon dioxide to form stems, roots and leaves, but not without a net loss of atmospheric oxygen throughout the process.

One of the many mysteries of the Permian extinction is that fossil soils from that era are unusually low in the heavier of carbon's two stable isotopes, carbon-13. For that to have occurred, the atmosphere's usual mix of carbon must have been diluted by a large admixture of the other isotope, carbon-12.

Some scientists have proposed that this carbon might have been belched out of volcanoes, which were known to have been extremely active at the end of the Permian. But volcanoes can't account for the isotope ratios seen in end-Permian soils, says Robert Berner, a geochemist from Yale University.

"Carbon dioxide from volcanoes could not give you that carbon isotope spike," he says. "You have to do it with something isotopically light, and the best candidate is methane."

Berner, who published his results last year in the Proceedings of the National Academy of Sciences, adds that the most likely source of methane is from the rapid release of methane hydrates from the seabed.

The soils from the end-Permian era are so heavily enriched with light carbon, however, that a truly enormous amount of methane must have been released into the atmosphere - enough to contain nearly twice as much carbon as is currently contained in every living thing on the surface of the earth, Retallack says.

Before the extinction, the Permian was an era when swamp-dwelling plants were forming large amounts of coal and, as a byproduct, jacking up the oxygen content of the atmosphere substantially beyond that which we know today. Geologists estimate that during this era, the air was comprised of 35 percent oxygen, compared with today's 21 percent.

The methane hydrates, Retallack calculates, would have consumed enough oxygen to reduce the atmospheric content all the way to 12 percent - roughly equivalent to the amount found today at an elevation of 16,500 feet. For creatures adapted to the high oxygen levels of the Permian, the effect would have been comparable to being lifted from sea level to the summit of Mount Everest.

Such a change would certainly have been a severe stress for many types of animals, says Dr. John West, a professor of medicine and physiology at UCSD, who studies human adaptations to high elevations. Andean miners can live indefinitely at elevations as high as 19,000 feet, West adds, but it's anyone's guess how well animals would adapt.

West notes that few animals live that high today, due to lack of food. But most of those that do, he says, have adaptations that wouldn't show in fossils, such as blood hemoglobin with an unusually high affinity for oxygen. Interestingly, he says, burrowing animals adapted to poorly ventilated tunnels show the same trait, a characteristic that he thinks might be more important to their survival than the barrel chests and short limbs observed by Retallack.

Future energy source

Retallack's theory has drawn cautious interest from some geophysicists, who regard it as intriguingly innovative. Others are more dubious.

Most scientists agree that the end of the Permian was accompanied by a rapid drop in atmospheric oxygen, but among geologists, "rapid" is a relative term. Berner thinks it took at least a million years, far too long to account for the rapid die-off that marked the Permian extinction.

But Retallack believes that while methane releases might have occurred in several stages spread across several thousand years, each one occurred quickly.

"I don't see any way to get (the methane) out slowly," he says. "I'm inclined to think of a catastrophic release within days or months."

Another question is whether the seabeds could have released enough methane to knock the atmospheric level of oxygen down by the amount proposed by Retallack.

Retallack says yes, but another methane hydrate researcher, Gerald Dickens of Rice University in Houston, thinks that Retallack's theory takes about 10 times too much methane.

Perhaps Retallack's use of the term "altitude sickness" has inadvertently polarized the debate. To most people, altitude sickness is an ailment that strikes quickly, when one ascends too far, too fast. Retallack admits that he himself was once struck down by the condition on an ill-fated attempt to climb Africa's 19,340-foot Mount Kilimanjaro.

Permian species may not have suffered sudden death from altitude sickness. Most could have been out-competed by the few that best adapted when the atmosphere changed.

More disturbing is the question of whether something similar could happen again. The Permian isn't the only time when geophysicists believe that large volumes of methane were released from the seabed. Something similar appears to have happened during the Eocene, 52 million years ago, although the amount of methane involved was considerably smaller.

And, methane hydrates exist today on the seabed, where in theory they could be released by another earthquake, volcanic eruption or asteroid impact similar to whatever event it was that may have triggered their release at the end of the Permian.

More importantly, humans are looking at methane hydrates as potential sources of energy. Before progressing too far, we'd better be sure that our extraction methods won't trigger large-scale releases. "The possibility for environmental catastrophe is a bit of a worry," Retallack says.

Richard A. Lovett is a freelance science writer in Portland, Ore. 

Copyright 2003 Union-Tribune Publishing Co. 


The International Herald Tribune, 13 November 2003

Matthew L. Wald NYT 

WASHINGTON Widespread hydrogen use has been enthusiastically embraced by corporations and environmentalists as a panacea for global warming and the depletion of fossil fuels.

Next week the Bush administration is bringing energy ministers of 15 countries to Washington for a meeting on hydrogen, and President George W. Bush pledged in his 2003 State of the Union address that "the first car driven by a child born today could be powered by hydrogen, and pollution-free."

But skeptics, and even some hydrogen advocates, say the use of hydrogen could instead make the air dirtier and the planet warmer. Hydrogen is only a place to store energy. Where the energy comes from in the first place is where the problems start.

The most ambitious use of hydrogen is in a car powered by a fuel cell, a batterylike device that turns hydrogen into electricity while emitting only heat and water vapor. Hydrogen can also be burned directly in engines much like those that run on gasoline, but the Energy Department goal is fuel cells because they get twice as much work out of a pound of hydrogen.

Companies and universities in North America are intensely researching development of a practical fuel cell.

The main source for hydrogen is natural gas, which is in short supply, is cumbersome to convert and may have better uses. Waiting in the wings is coal, burned in old power plants around the world that are already the focus of a dispute over their emissions.

The long-term hope is to make hydrogen from emission-free "renewable" technologies, like windmills or solar cells. In fact, hydrogen may be an essential step to translate the energy of wind or sunlight into power to turn a car's wheels, experts say. But electricity from renewable technologies is costly. At Sharp Solar, which says it is the world's largest maker of solar cells, the general manager, Ronald Kenedi, said it was possible that the energy source to produce hydrogen for vehicles would initially not be the sun or wind. "The first stop on the hydrogen trail will be coal," he said.

A likely source of hydrogen is from a machine called an electrolyzer, which is like a fuel cell in reverse. The fuel cell combines oxygen from the air with hydrogen to produce an electric current, with water as a byproduct, while an electrolyzer runs an electric current through water to split the water molecule into its constituent hydrogen and oxygen atoms. The problem is that if the electricity came off the national power grid to run an electrolyzer, about half of it, on average, would be generated by coal.

The president's proposal contained an implicit recognition that a big part of the fuel-cell question is the fuel. He called for spending $1.2 billion on hydrogen to include money for production, delivery and storage. Another problem is emissions. According to the Energy Department, an ordinary gasoline-powered car emits 374 grams of carbon dioxide per mile, or 1.6 kilometers, it is driven, counting the energy used to make the gasoline and deliver it. The same car powered by a fuel cell would emit nothing, but if the energy required to make the hydrogen came from the electric grid, the emissions would be 436 grams per mile. Similarly, the car would not emit nitrogen oxides, a precursor of smog, but the power plant would.

Copyright 2003 the International Herald Tribune All Rights Reserved

========= LETTERS =========


Jeremie Vaubaillon <>

Just a few words to recall that the Leonid meteor shower level from the 1533
trail predicted by our method is very uncertain. For more information,
please visit:

Thanks a lot!

Jeremie Vaubaillon

* Institut de Mecanique Celeste et de Calcul
* des Ephemerides (, ex
* 77 Avenue Denfert Rochereau
* 75014 PARIS
* tel : +33 (0)1 40 51 22 66
* fax : +33 (0)1 40 51 20 58
* URL :


Keith Cowing

The Bush Administration is nearly finished with an internal effort to develop a new space
policy for America. The process has been performed in a quiet cloistered manner, out of
public view. The longer this process has gone on, the more interested parties want to know
what is going on. Speculation has started to mount to the point that certain specific venues
for "an announcement" by the President are circulating inside and outside of the White House....

Many have called for a specific destination to be named - one that will pull or push technology
development - rather than Sean O'Keefe's currently espoused approach wherein NASA seeks to
develop technology and then see what destination opportunities it might provide down the road.
Word from knowledgeable sources would suggest that an overt Kennedy-esque commitment to send
humans to Mars is simply not in the cards. Indeed, Mars (as an option) is not on the table at
the present time.

Rather, the focus seems to be coalescing around sending humans back to the Moon and to the
establishment of a inner solar system infrastructure that would allow decisions to where to
go next (e.g. Mars, asteroids, etc.) to be made once certain technological and operational
unknowns are better understood....


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