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Friday, May 16, 2008

Key molecule discovered in Venus's atmosphere

Hydroxyl an important but difficult-to-detect molecule is made up of a hydrogen and oxygen atom each. It has been found in the upper reaches of the Venusian atmosphere some 100 km above the surface by Venus Expresss Visible and Infrared Thermal Imagi ...
Hydroxyl, an important but difficult-to-detect molecule, is made up of a hydrogen and oxygen atom each. It has been found in the upper reaches of the Venusian atmosphere, some 100 km above the surface, by Venus Express’s Visible and Infrared Thermal Imaging Spectrometer, VIRTIS. Credits: ESA (Image by C. Carreau)

Venus Express has detected the molecule hydroxyl on another planet for the first time. This detection gives scientists an important new tool to unlock the workings of Venus’s dense atmosphere.

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Hydroxyl, an important but difficult-to-detect molecule, is made up of a hydrogen and oxygen atom each. It has been found in the upper reaches of the Venusian atmosphere, some 100 km above the surface, by Venus Express’s Visible and Infrared Thermal Imaging Spectrometer, VIRTIS.

The elusive molecule was detected by turning the spacecraft away from the planet and looking along the faintly visible layer of atmosphere surrounding the planet’s disc. The instrument detected the hydroxyl molecules by measuring the amount of infrared light that they give off.

The band of atmosphere in which the glowing hydroxyl molecules are located is very narrow; it is only about 10 km wide. By looking at the limb of the planet, Venus Express looked along this faint atmospheric layer, increasing the signal strength by about 50.

Hydroxyl is thought to be important for any planet’s atmosphere because it is highly reactive. On Earth it has a key role in purging pollutants from the atmosphere and is thought to help stabilise the carbon dioxide in the martian atmosphere, preventing it from converting to carbon monoxide. On Mars it is also thought to play a vital role in sterilising the soil, making the top layers hostile to microbial life.
The reactive molecule has been seen around comets, but the method of production there is thought to be completely different from the way it forms in planetary atmospheres.

“Because the venusian atmosphere had not been studied extensively before Venus Express arrived on the scene, we have not been able to confirm much of what our models tell us by observing what is actually happening. This detection will help us refine our models and learn much more,” says one of the Principal Investigators of the VIRTIS experiment, Giuseppe Piccioni, from the Istituto di Astrofisica Spaziale e Fisica Cosmica in Rome, Italy.

On Earth, the glow of hydroxyl in the atmosphere has been shown to be closely linked to the abundance of ozone. From this study, the same is thought to be true at Venus. Now, scientists can set about estimating the amount of ozone in the planet’s atmosphere.

Venus Express has shown that the amount of hydroxyl at Venus is highly variable. It can change by 50% from one orbit to the next and this may be caused by differing amounts of ozone in the atmosphere.

“Ozone is an important molecule for any atmosphere, because it is a strong absorber of ultraviolet radiation from the Sun,” says Piccioni. The amount of the radiation absorbed is a key parameter driving the heating and dynamics of a planet’s atmosphere. On Earth, it heats the stratosphere (layer of the atmosphere) making it stable and protecting the biosphere from harmful ultraviolet rays.

Computer models will now be able to tell how this jump and drop in ozone levels over short intervals affects the restless atmosphere of that world.

“Venus Express has already shown us that Venus is much more Earth-like than once thought. The detection of hydroxyl brings it a step closer,” says Piccioni.

He and his colleagues are only reporting the initial detection from a few orbits in their latest paper. They are working on the analysis of data from about 50 other orbits and more observations will follow.

First detection of hydroxyl in the atmosphere of Venus by G. Piccioni et al. has been published in today's issue of Astronomy & Astrophysics Letters.
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Astronomers measure temperature of the early universe

Carbon monoxide gas in distant galaxies imprints its signature on light from an even more distant quasar as it propagates towards Earth (Illustration: European Southern Observatory)
Carbon monoxide gas in distant galaxies imprints its signature on light from an even more distant quasar as it propagates towards Earth (Illustration: European Southern Observatory)

We cannot go back in time and stick a thermometer in the early universe, but astronomers have done the next best thing, using an indirect technique to find out what the universe's temperature was 11 billion years ago. It was a chilly 9 K (-264 °C) back then, which is still warmer than today's prevailing temperature of less than 3 K (-270 °C).

Some of the coldest objects in the universe are gas clouds that fill the space between stars and galaxies. But even these are warmer than absolute zero, or 0 K. That is because they are heated by radiation leftover from the universe's earliest times.

Called the cosmic microwave background (CMB), this radiation was emitted by the hot plasma that filled the universe a mere 380,000 years after the big bang, which took place an estimated 13.7 billion years ago.

But as the universe expanded, the electromagnetic waves that comprise this radiation were stretched to longer wavelengths and lower energies, decreasing the radiation's temperature. Today, that temperature is just 2.7 K.

Now, a team led by Raghunathan Srianand of the Inter-University Centre for Astronomy and Astrophysics in Pune, India, has measured what the CMB temperature was 11 billion years ago, when the universe was just a fifth its current age.

Indirect route

They found it to be 9.15 K back then, with an uncertainty of 0.7 K in either direction. That is "in excellent agreement" with the 9.3 K temperature predicted in the big bang scenario, says team member Patrick Petitjean of the Institut d'Astrophysique in Paris, France.

The astronomers arrived at their figure by a very indirect route. What they actually measured was the temperature of carbon monoxide gas in a galaxy about 11 billion light years away.

The gas was detected by the way it intercepts light from an even more distant object called a quasar – a bright galaxy whose central black hole is consuming its surroundings.

The team used the Very Large Telescope (VLT) array in Paranal, Chile, to measure the wavelengths where the carbon monoxide absorbs the quasar's light. The wavelengths affected depend on the temperature of the galaxy's gas, whose heat is thought to come from the CMB.

Charles Bennett, chief scientist for NASA's Wilkinson Microwave Anisotropy Probe (WMAP) mission, which measures the CMB, says it is important to make such measurements to test scientists' expectations. "It's nice to see consistent things in different ways," he told New Scientist.

Journal reference: Astronomy & Astrophysics (vol 482, p L39)

Cosmology – Keep up with the latest ideas in our special report.

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How to Escape From a Black Hole


According to Einstein's theory of general relativity, black holes are regions of space where gravity is so strong that not even light can escape. And in the 1970's physicist Stephen Hawking asserted that any information sucked inside a black hole would be permanently lost. But now, researchers at Penn State have shown that information can be recovered from black holes.

A fundamental part of quantum physics is that information cannot be lost, so Hawking's claim has been debated. His idea was generally accepted by physicists until the late 1990s, when many began to doubt the assertion. Even Hawking himself renounced the idea in 2004. Yet no one, until now, has been able to provide a plausible mechanism for how information might escape from a black hole. A team of physicists led by Abhay Ashtekar, say their findings expand space-time beyond its assumed size, providing room for information to reappear.

Ashtekar used an analogy from Alice in Wonderland: "When the Cheshire cat disappears, his grin remains," he said. "We used to think it was the same way with black holes. Hawking's analysis suggested that at the end of a black hole's life, even after it has completely evaporated away, a singularity, or a final edge to space-time, is left behind, and this singularity serves as a sink for unrecoverable information."

But the Penn State team suggest that singularities do not exist in the real world. "Information only appears to be lost because we have been looking at a restricted part of the true quantum-mechanical space-time," said Ashtekar. "Once you consider quantum gravity, then space-time becomes much larger and there is room for information to reappear in the distant future on the other side of what was first thought to be the end of space-time."

According to Ashtekar, space-time is not a continuum as physicists once believed. Instead, it is made up of individual building blocks, just as a piece of fabric, though it appears to be continuous, is made up of individual threads. "Once we realized that the notion of space-time as a continuum is only an approximation of reality, it became clear to us that singularities are merely artifacts of our insistence that space-time should be described as a continuum."

To conduct their studies, the team used a two-dimensional model of black holes to investigate the quantum nature of real black holes, which exist in four dimensions. That's because two-dimensional systems are simpler to study mathematically. But because of the close similarities between two-dimensional black holes and spherical four-dimensional black holes, the team believes that this approach is a general mechanism that can be applied in four dimensions. The group now is pursuing methods for directly studying four-dimensional black holes.

The team's work will be published in the May 20, 2008 issue of the journal Physical Review Letters.

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'Nail-biting' descent to Mars

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Scientists are preparing for "seven minutes of terror" as a Nasa spacecraft makes a nail-biting descent to the surface of Mars.

The Phoenix lander needs to perform a series of challenging manoeuvres along the way as it attempts to land in the planet's polar north.

It then begins a three-month mission to investigate Mars' geological history and potential habitability.

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Embryonic pathway delivers stem cell traits

Studies of how cancer cells spread have led to a surprising discovery about the creation of cells with adult stem-cell characteristics, offering potentially major implications for regenerative medicine and for cancer treatment.

Some cancer cells acquire the ability to migrate through the body by re-activating biological programs that have lain dormant since the embryo stage, as the lab of Robert Weinberg, a member of the MIT-affiliated Whitehead Institute for Biomedical Research, has helped to demonstrate in recent years. Now scientists in the Weinberg lab have shown that both normal and cancer cells that are induced to follow one of these pathways may gain properties of adult stem cells, including the ability to self-renew.

In a paper published online by Cell on May 15, former postdoctoral researcher Sendurai Mani and his colleagues demonstrated in mice and in human cells that cells that have undergone an "epithelial-to-mesenchymal" (EMT) transition acquire several important characteristics of stem cells. Conversely, the researchers also showed that naturally existing normal stem cells as well as tumor-seeding cancer stem cells show characteristics of the post-EMT cells, including the acquisition of mesenchymal cell traits, which are usually associated with connective tissue cells.

Epithelial cells, which make up most of the human body, bind together in sheet-like structures. In embryonic development, the EMT process breaks up cell-cell adhesion in the epithelial layer, and converts epithelial cells into more loosely associated mesenchymal cells. In the context of cancer development, some cancer cells within a primary cancer may undergo an EMT, migrate through the body to their end destination, and there resume their epithelial form through a reverse process (the mesenchymal-to-epithelial transition).

Mani and his colleagues have identified FOXC2, one of the key genes involved in invasion and metastasis. In addition, FOXC2 appears to program the metastatic ability of some breast cancers.

Mani knew that during embryonic development, FOXC2 expression is restricted to mesoderm and mesoderm-derived cells when they are in an undifferentiated state and its expression disappears once these cells differentiate. Similarly, his experiments showed that epithelial cells that undergo EMT express FOXC2, but that expression is lost when they revert back to an epithelial state.

In collaboration with Andrea Richardson and Jeffery Kutok, pathologists at Boston's Brigham and Women's Hospital, Mani went on to study FOXC2 expression in normal human breast tissue. It turned out that such cells were located precisely where researchers expect to find mammary epithelial stem cells.

As he pondered these findings and the earlier results about FOXC2's role in metastasis, Mani wondered: Just what were these cells generated by EMT that expressed FOXC2?

Were they simply fibroblasts, the most common cells in normal connective tissue? Or were they actually stem cells?

"I asked Mai-Jing Liao, another postdoc in the Weinberg lab, to check whether the cells generated by EMT would have any stem-cell properties," recalls Mani, now an assistant professor in the department of molecular pathology at the University of Texas's M. D. Anderson Cancer Center in Houston. "He said, 'You must be out of your mind, but it won't take more than half an hour to check.'"

Much to Liao's surprise, when he examined cells that had undergone an EMT, his tests did highlight surface proteins that are key markers for stem cells.

The researchers found that the cells that underwent the EMT process were mesenchymal-like in appearance and demonstrated stem-cell surface markers. The cells also displayed an increased ability to grow in suspension, forming structures called mammospheres--another trait of mammary stem cells. Some cells in the resulting mammospheres showed, in turn, stem-cell markers, indicating they could differentiate into two kinds of mammary cells. And cells in the mammospheres retained their stem-cell properties even after the EMT induction process was stopped.

Furthermore, when the Weinberg lab scientists isolated stem-cell-like cells from cultured human mammary epithelial cells or from mouse breast tissue, their properties were very similar to the EMT-induced cells. Working with Kornelia Polyak of Dana-Farber Cancer Institute and Harvard Medical School, Mani found that this was also true with normal and tumor cells obtained from human patients.

"This for us is a very-exciting discovery, not only because of its unexpectedness but because it offers a route by which one could in principle generate unlimited numbers of stem cells committed to create a specific cell type," says Weinberg, who is also a professor of biology at MIT and a member of the David H. Koch Institute for Integrative Cancer Research. "One could imagine, for example, that if one takes skin cells and induces them to undergo an EMT, they could become skin stem cells."

Importantly, the researchers also demonstrated that inducing the EMT process can produce cells with many characteristics of cancer stem cells (beginning in 2003, scientists in various labs have identified these self-renewing, tumor-seeding cells in a number of solid tumors).

This finding could help to answer a key question about metastasis: When tumor cells spread into different sites, how do they multiply enough to form a dangerous new tumor?

"If you take a population of human cancer cells that normally form a tumor very inefficiently and induce an EMT, their tumor-initiating abilities increase by about a hundred-fold, so that it takes about 10,000 cells rather than a million cells to form a tumor," says Wenjun Guo, co-lead author on the paper and postdoctoral researcher in the Weinberg lab. "This suggests cancer stem cells are using pre-existing normal stem cell machinery to propagate their own self-renewal and therefore their tumor-initiating ability."

Mani is continuing his research on the EMT/cancer stem cell connection and its role in cancer metastasis at the M. D. Anderson Cancer Center. Researchers in the Weinberg lab will investigate the EMT process with other cell lines. They also will attempt to give final proof in mice that the process creates completely defined stem cells, by taking cells from mouse mammary fat pads, inducing an EMT for some of the cells, returning the resulting cells to the fat pad and seeing if they can regenerate the mammary gland.

This research was supported by the Breast Cancer Research Foundation, the MIT Ludwig Center for Molecular Oncology and the National Cancer Institute. Mani was supported by a Department of Defense postdoctoral fellowship.
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Girl's twin found inside her stomach

ATHENS, Greece (AP) -- A nine-year-old girl who went to hospital suffering from stomach pains was found to be carrying her embryonic twin, doctors in central Greece said Thursday.

Doctors at Larissa General Hospital examined the girl and surgically removed a growth they later discovered was an embryo about six centimeters (more than two inches) long.

"They could see on the right side that her belly was swollen, but they couldn't suspect that this tumor would hide an embryo," hospital director Iakovos Brouskelis said.

The girl has made a full recovery, he said.

Andreas Markou, head of the hospital's pediatric department, said the embryo was a formed fetus with a head, hair and eyes, but no brain or umbilical cord.

Markou said cases where one of a set of twins absorbs the other in the womb occur in one of 500,000 live births.

The girl's family did not want to be identified, hospital officials said.
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Whales are 'cheetahs of the deep'

A pilot whale was seen to surface with squid in its mouth

Super-fast pilot whales have been observed sprinting after prey, likely to include giant squid.

The rapid pursuit has brought comparisons with the fleet-footed land predator, the cheetah.

The cetaceans even use the same, highly specialised hunting strategy that cheetahs use, scientists report in the Journal of Animal Ecology.

They say it gives the lie to our perception that deep sea whales are slow, energy-saving creatures.

Short-finned pilot whales seem to be the greatest burst-speed athletes of the deep-diving mammals
Aguilar Soto, La Laguna University

It is the first time such remarkable behaviour - occurring hundreds of metres underwater, in complete darkness - has been recorded.

"As far as we know, no other whale has been recorded to swim nearly as fast at depth," says marine biologist Natacha Aguilar Soto, of La Laguna University in Tenerife, Spain.

"Short-finned pilot whales seem to be the greatest burst-speed athletes of the deep-diving mammals."

Energetic sprint

Aguilar Soto is a member of an international team of researchers drawn from La Laguna University, Woods Hole Oceanographic Institution in Massachusetts, US, and Aarhus University, Denmark.

Cheetah (BBC)
Land speed king: Cheetahs can move at over 100km/h

The team tagged and studied 23 short-finned pilot whales (Globicephala macrorhynchus) living off the coast of the Canary Islands, one of only three places in the world that these whales permanently reside.

The tags, designed by co-author Mark Johnson of Woods Hole, recorded the speed, depth and direction of the whales' dives, and also the sounds made and heard by the whales.

During the day, the whales are frequently seen lazing on the surface, often in social groups (see video). That led scientists to previously think the whales only hunt at night. But the tags demonstrate the whales also hunt during the day. And when they do, they dive deep, and they dive fast.

Tags showed the whales take just 15 minutes to dive to depths of 800m to 1,000m (0.6 mile), and more.

And when they pinpoint their prey, the whales surge after it, reaching speeds of nine metres per second, or 32 kilometres per hour (20mph). What's more, they may keep up the sprint for 200m (650ft), before either catching the prey or giving up the chase.

The discovery fundamentally challenges our perceptions of how deep-sea creatures behave, says Aguilar Soto.

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Pilot whales can also enjoy a more sedate pace of life (Sergio Hanquet)

Until now, researchers assumed that deep-diving whales moved relatively slowly, due to the need to conserve oxygen whilst holding their breath.

"It was completely unexpected that short-finned pilot whales sprint at depth with limited oxygen reserves. Cheetahs, for example, more than double their breathing rate during chases," says Aguilar Soto.

So like cheetahs, pilot whales must therefore follow a high-risk, high-gain hunting strategy based on high-speed, energetically expensive sprints. But somehow, the whales do it while still holding their breath. And that may explain why they are spotted lazing on the surface - the whales may be actually recovering from the exertion of the hunt.

Deep battle

There is also tantalising, indirect evidence that the whales may sometimes chase down giant squid.

During the dives, the acoustic tags revealed that the whales switched from slower echolocation clicks to a fast series of clicks, or buzz.

That allows them to "see with sound" with greater resolution in the darkness, says co-author Peter Madsen of Aarhus University.

"The analogy is like going from snap-shots to video," he says, indicating the whales are trying to capture prey after the sprints.

But "the prey must be large or calorific to reward the deep dives, and they must be able to move rapidly given the top speeds we clocked for the whales," says Aguilar Soto.

One animal fits the bill, the giant squid Architeuthis. "We found a piece of fresh Architeuthis arm floating in the vicinity of diving pilot whales and findings of bitten Architeuthis are common in the area where the whales live," Aguilar Soto explains.

Also, colleague Pablo Aspas recently took a photo of a pilot whale half-breaching with a piece of large squid in its mouth (pictured above).

"Its colour and the shape of the cups indicate it may well belong to Architeuthis and the size of the piece indicates that the full length of the tentacle would be more than two metres, corresponding to a squid 4-5 metres long and some 180kg in weight," says cephalopod expert Angel Guerra of the Institute for Marine Investigations in Vigo, Spain.

"We have imagined battles between sperm whale and giant squid. But it may turn out that it is pilot whales, one-third the size of sperm whales, which are sprinting for the giant squid!" says Aguilar Soto.
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Billions of electronic-eating 'crazy rasberry ants' invade Texas

Tom Rasberry

Tom Rasberry, the exterminator, with the alien ants he first identified as a problem

It sounds like the plot of a farfetched science fiction movie. Unfortunately for the residents of Texas, it is very much a reality: billions of tiny reddish-brown ants have arrived onshore from a cargo ship and are hell-bent on eating anything electronic.

Computers, burglar alarm systems, gas and electricity meters, iPods, telephone exchanges – all are considered food by the flea-sized ants, for reasons that have left scientists baffled.

Having ruined pumps at a sewage facility, the ants are now marching towards Nasa’s Johnson Space Centre and William P. Hobby airport, Houston, putting state officials in a panic. “They’re itty-bitty things, and they’re just running everywhere,” said Patsy Morphew, a resident of Pearland, on the Gulf Coast.

She spends hours sweeping them off her patio and scooping them out of her pool by the cupful. “There’s just thousands and thousands of them. If you’ve seen a car racing, that’s how they are. They’re going fast, fast, fast. They’re crazy.”

Crazy is the the right word. The ants are known as “crazy rasberry ants”: crazy because they seem to move in a random scrum as opposed to marching in regimented lines, and rasberry after a pioneering exterminator, Tom Rasberry, who first identified them as a problem.

The ants – also known as paratrenicha species near pubens – have so far spread to five counties in the Houston area. Scientists are not sure from where they originate but they seem to be related to a type of ant from the Caribbean. “At this point it would be nearly impossible to eradicate the ants because they are so widely dispersed,” said Roger Gold, a Texas A&M University entomologist. He added that the only upside to the invasion was that the crazy rasberry ants ate fire ants, which sting humans during the long, hot Texas summers.

Unfortunately, the ants also like to suck the moisture from plants, feed on precious insects such as ladybirds and eat the hatchlings of a small, endangered type of grouse known as the Attwater prairie chicken. They also bite humans – although not with a sting like fire ants.

Perhaps their most remarkable characteristic, however, is that they are attracted to electrical equipment. Pest control specialists say that they are inundated with calls from homes and businesses now that the warm, humid season has begun, with literally billions of the ants wreaking havoc across the state. Worse, the ants refuse to die when sprayed with over-the-counter poison. Even killing the queen of a colony doesn’t do any good, because each colony has multiple queens.

The Texas Department of Agriculture said that it was working with researchers from A&M University and the Environmental Protection Agency to find new ways to stop the ants.

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NASA Team Pinpoints Human Causes of Global Warming

1432861455_ec53c9a238_2 Human-caused climate change has impacted a wide range of Earth's natural systems, from permafrost thawing to plants blooming earlier across Europe to lakes declining in productivity in Africa.

Cynthia Rosenzweig of NASA's Goddard Institute for Space Science in New York and scientists at 10 other institutions have linked physical and biological impacts since 1970 with rises in temperatures during that period, including changes to physical systems, such as glaciers shrinking, permafrost melting, and lakes and rivers warming. Impacts also included changes to biological systems, such as leaves unfolding and flowers blooming earlier in the spring, birds arriving earlier during migration periods, and ranges of plant and animal species moving toward the poles and higher in elevation. In aquatic environments such as oceans, lakes, and rivers, plankton and fish are shifting from cold-adapted to warm-adapted communities.

"This is the first study to link global temperature data sets, climate model results, and observed changes in a broad range of physical and biological systems to show the link between humans, climate, and impacts," said Rosenzweig, lead author of the study.

Rosenzweig and colleagues also found that the link between human-caused climate change and observed impacts on Earth holds true at the scale of individual continents, particularly in North America, Europe, and Asia.

Photograph of a forest When permafrost melts, the layer of loose soil deepens and trees lose their foundations and tip over. Similar impacts across Earth are likely due to human-caused climate change.

To arrive at the link, the authors built and analyzed a database of more than 29,000 data series pertaining to observed impacts on Earth's natural systems, collected from about 80 studies each with at least 20 years of records between 1970 and 2004.

The team conducted a "joint attribution" study in which they showed, first, that at the global scale, about 90 percent of observed changes in diverse physical and biological systems are consistent with warming. Other driving forces, such as land use change from forest to agriculture, were ruled out as having significant influence on the observed impacts.

Next, the scientists conducted statistical tests and found that the spatial patterns of observed impacts closely match temperature trends across the globe, to a degree beyond what can be attributed to natural variability. So, the team concluded that observed global-scale impacts are very likely due to human-caused warming.

"Humans are influencing climate through increasing greenhouse gas emissions and the warming is causing impacts on physical and biological systems that are now attributable at the global scale and in North America, Europe, and Asia," said Rosenzweig.

An unexpected consequence of rising temperatures may be its effect on long-dead prehistoric life.

For thousands of years animal waste, and other organic matter left behind on the Arctic tundra, have been sealed off from the environment by permafrost. Now climate change is melting the permafrost and freeing mass quantities of prehistoric “ooze” from its state of suspended animation.

Russian scientist, Sergei Zimov, has been studying climate change in Russia's Arctic for 30 years now. He is worried that as this organic matter becomes exposed to the air it will drastically accelerate global warming predictions even beyond some of the most pessimistic forecasts.

"This will lead to a type of global warming which will be impossible to stop," he said.

According to Zimov, when the organic matter left behind by mammoths and other wildlife is exposed to the air by the thawing permafrost, microbes that have been dormant for thousands of years will spring back into action. They’ll begin once again to emit carbon dioxide and methane gas as a by-product. Zimov says thought the microbes are tiny, they will start emitting these gases in enormous quantities simply because there will be a lot of them.

Yakutia is a region in the north-eastern corner of Siberia, where a belt of permafrost contains the mammoth-era soil. It covers an area roughly the size of France and Germany combined. There is even more of it elsewhere in Siberia.

"The deposits of organic matter in these soils are so gigantic that they dwarf global oil reserves," Zimov said. U.S. government statistics show mankind emits about 7 billion tons of carbon a year."Permafrost areas hold 500 billion tons of carbon, which can fast turn into greenhouse gases," Zimov added. "If you don't stop emissions of greenhouse gases into the atmosphere ... the Kyoto Protocol (an international pact aimed at reducing greenhouse emissions) will seem like childish prattle."

On other continents, including Africa, South America, and Australia, documentation of observed changes in physical and biological systems is still sparse despite warming trends attributable to human causes. The authors concluded that environmental systems on these continents need additional research, especially in tropical and subtropical areas where there is a lack of impact data and published studies.

The study, published May 15 in the journal Nature, concludes that human-caused warming is resulting in a broad range of impacts across the globe.

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Wildlife populations 'plummeting'

Hammerhead shark
Over-fishing and demand for their fins as a delicacy have hit shark numbers

Between a quarter and a third of the world's wildlife has been lost since 1970, according to data compiled by the Zoological Society of London.

Populations of land-based species fell by 25%, marine by 28% and freshwater by 29%, it says.

Humans are wiping out about 1% of all other species every year, and one of the "great extinction episodes" in the Earth's history is under way, it says.

Pollution, farming and urban expansion, over-fishing and hunting are blamed.

River dolphin

The Living Planet Index, compiled by the society in partnership with the wildlife group WWF, tracks the fortunes of more than 1,400 species of fish, amphibians, reptiles, birds and mammals, using scientific publications and online databases.

It said numbers had declined by 27% in the 35 years from 1970 to 2005.

Some of the worst hit are marine species which saw their numbers plummet by 28% in just 10 years, between 1995 and 2005.

Populations of ocean birds have fallen by 30% since the mid 1990s, while land-based populations have dropped by 25%.

Reduced biodiversity means millions of people face a future where food supplies are more vulnerable to pests and disease and where water is in irregular or short supply
James Leape
Director general, WWF UK

Among the creatures most seriously affected have been African antelopes, swordfish and hammerhead sharks.

Another, the baiji - or Yangtze River Dolphin - may have been lost altogether.

The findings were released ahead of a meeting of the Convention on Biodiversity in the German city of Bonn.

The convention was signed in 1992 with the aim of stabilising the loss of species. In 2002, member states pledged to achieve a "significant reduction" in the current rate of biodiversity loss by 2010.

But the Zoological Society said governments had since failed to put in place policies necessary to achieve that goal.

It said that while species' decline does appear to have flattened off in recent years, it is "very unlikely" that the 2010 target will be reached.

Impact on humans

The WWF said that over the next 30 years, climate change was also expected to become a significant threat to species.

Topi antelope in Africa
Land-based species, such as African antelopes, have fallen by 25%

Colin Butfield, head of campaigns at WWF UK, said: "Biodiversity underpins the health of the planet and has a direct impact on all our lives, so it is alarming that despite an increased awareness of environmental issues we continue to see a downward trend."

The charity also warned that a failure to stop biodiversity loss would have a direct impact on humans.

Director general James Leape said: "Reduced biodiversity means millions of people face a future where food supplies are more vulnerable to pests and disease and where water is in irregular or short supply.

"No-one can escape the impact of biodiversity loss because reduced global diversity translates quite clearly into fewer new medicines, greater vulnerability to natural disasters and greater effects from global warming."

The WWF is calling on governments meeting in Bonn to honour their commitments to put in place effective protected areas for wildlife and to adopt a target to achieve net annual zero deforestation by 2020.

The UK's Biodiversity Minister, Joan Ruddock, said the report showed that the international community had to work together to stem the decline.

"The fact that human activities have caused more rapid changes in biodiversity in the last 50 years than at any other time in human history should concern us all," she said.

"Supporting wildlife is critical to all our futures and the UK will continue to give strong support to international action.

"Schemes such as the Darwin Initiative have used UK expertise to help more that 490 wildlife conservation, regeneration and research projects in 146 countries."

Lifestyles and the consumption of resources vary widely from country to country. On average each person needs 2.2 global hectares to support the demands they place on the environment, but the planet is only able to meet consumption levels of 1.8 global hectares per person.

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Tommy Lee saves the planet!

planet_green.03.jpgA scene from Planet Green's upcoming "WA$TED," a show that highlights household waste.

NEW YORK (Fortune) -- Until recently, celebrity rocker Tommy Lee didn't worry about the environment. He was too busy being one of his industry's foremost rude boys. Now the Motley Crue drummer thinks it's "really cool" to evangelize about how the earth is in trouble.

It's especially cool if you can spread the word on your own cable television show. Lee and rapper Chris "Ludacris" Bridges are the stars of "Battleground Earth," a reality show in which the two recording artists compete to see who is the more ardent protector of the planet. They take on challenges like recycling trash after an Oakland As game and cooking corn dogs to produce fuel their bio-diesel tour buses.

No, this is not MTV's latest offering for teen guys who want to take a break from playing "Grand Theft Auto 4."

"Battleground Earth" is the most widely publicized show on Planet Green, Discovery Communications' environmentally-themed lifestyle and entertainment network debuting June 4. Discover has invested an estimated $50 million creating Planet Green shows like "Battleground Earth" and others hosted by "Entourage" star Adrian Grenier, gross-out comic Tom Green, and Food Network cuisine artist Emeril Lagasse.

The new network will be heavy on glitz and even a little tacky at times. But Discovery knows exactly what it is doing with Planet Green.

David Zaslav, Discovery's CEO, hopes to take the company, based in Silver Spring, Md., public later this year. Discovery is coming off a great year. Rich Greenfield, an analyst at Pail Research, notes that revenues rose 12% last year while earnings before interest, taxes, depreciation and amortization - a widely used profit metric in the media industry - climbed 30%. But he also points out that two of Discovery's ten networks - Discovery Channel and TLC - were responsible for much of this largesse.

If Discovery wants to keep growing like this, it needs to strengthen its weaker networks. One of the laggards happens to be Discovery Home, known (or perhaps not known) for its shows like "Licensed To Grill" and "Toolbelt Diva." The company is jettisoning Discovery Home and re-branding the network as Planet Green. "Discovery Home was stuck at the starting gates," Greenfield says. "This channel presents a significant opportunity."

This is a natural step for Discovery. The Discovery Channel had a big hit last year with "Planet Earth," a co-production with the BBC. This exquisitely-filmed series about the effects of global warming attracted an average of 5.1 million viewers on Sunday nights, a huge number by cable standards. Discovery took the show's success as a sign that the country was ready for a 24-hour network devoted to the environment, albeit one with the lighter touch than its flagship channel.

"The Discovery Channel addresses the science, the reason a crisis is at hand," says Eileen O'Neill, president of Planet Green. "Our network will inform, activate and inspire people though a very direct, entertaining approach."

Planet Green isn't likely to attract a huge audience. But that may not matter. Brad Adgate, senior vice president of research for Horizon Media, a New York-based ad agency, says advertisers are eager to reach people who care about the environment. "The type of viewers who turn into this network will probably be a little more upscale and well educated," he says. "They'll be a little more highbrow than the average TV viewer."

Here's a sign that Discovery is on the right track with Planet Green. The new network's website has already attracted blue-chip sponsors like Wal-Mart (WMT, Fortune 500), Proctor & Gamble (PG, Fortune 500), Caterpillar (CAT, Fortune 500) and General Motors (GM, Fortune 500).


Never mind that much of what Planet Green will offer - reality shows, cooking shows, home improvement fare - is available elsewhere on cable television. The network's pre-launch success suggests that big advertisers are happy to write checks if this kind of programming has a green message. They may even be willing to underwrite Tommy Lee's corn dog cooking contest. No wonder he's joined the green movement. To top of page

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A Truck That Runs on Coffee Grounds (and How Wood-Gas Powers Cars With Garbage)


Photo Credits: deborah sherman photography

The Cafe Racer Truck Runs on 100% Recycled Coffee Grounds

A commenter on Ben’s wood-powered truck post pointed us to a similar car hack. The truck above is also powered by a wood gas generator, except this one runs on coffee grounds. The Cafe Racer is a 1975 GMC pickup that essentially burns up used coffee to create a combustible gas. The gas is filtered on its way to the engine and, Viola, a caffeine-powered truck.

It’s interesting to note that this and the last vehicle mentioned are promoting a specific fuel (wood and coffee grounds), since the onboard wood gas generators can gasify almost any type of combustible material.

Gasification is a non-selective method using heat and a controlled amount of oxygen to convert biomass into a flammable vapor. In addition to Coffee Grounds, the Cafe Racer could use wood chips, old tires, and municipal trash, almost anything—which, by the way, is the same technology Coskata is using to make cellulosic ethanol out of garbage.

As Wikipedia puts it, gasification “was an important and familiar 19th century technology” that was commonly used until petroleum took over around the close of WWII. Although popular at that time, wood gas conversions are a bit of a throw back, but you never know what could gain popularity as gas prices continue to rise. Additionally, wood gas generators aren’t restricted to vehicles, and have found use in heating, cooking, and electricity production.

So how can a wood gas generator power a truck?

The reason a wood gas generator can power cars and trucks is that the internal combustion engine is actually powered by vapor, not liquid. In a gasoline-powered engine, gasoline is vaporized before entering the combustion chamber. Diesel is a little different; it’s sprayed into the combustion chamber as fine droplets which burn as they vaporize. Either way, if you can put a clean combustible vapor into the engine, you’ve got power*.

(*Just to mention where this information is coming from, I thought I’d point out this interesting factoid: back in 1989, FEMA sponsored a series of “emergency technology assessments” that included a book on gasification conversions. The title of the book is “Construction of a Simplified Wood Gas Generator for Fueling Internal Combustion Engines in a Petroleum emergency.”)

Gasifying a solid material partially burns it, which preserves some of the energy that would normally be wasted in the gas (otherwise there wouldn’t be anything left for the engine to burn). The gas contains a mixture of carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2), nitrogen (N), and a small amount of methane (CH4).

The big question for wood gas use is (as usual), how do these systems compare to other petroleum alternatives in terms of environmental impact? The group behind Cafe Racer claims that it’s a carbon-negative demonstration vehicle, but they don’t substantiate that on their website. I wasn’t able to find much on the issue, except the risk of death from carbon monoxide poisoning in poorly designed systems, but my gut instinct tells me this isn’t the cleanest way to get around. If you know of a resource on the emissions of wood gas generators, please send it my way.

The important point here isn’t so much that you can run a truck on wood gas produced from waste materials (even though that’s pretty cool), but that this technology could play a major role in producing petroleum alternatives in the near future (more on that later).

If you enjoyed reading about this, check out these links, and see more pictures of the Cafe Racer below:

Posts Related To Wood Gas Generators and Other Car Hacks:


Photo Credit: deborah sherman photography: http://www.deborahsherman.com/, (studiodeb on Flickr). Used by permission (thanks!).

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Earth Impacts Linked to Human-Caused Climate Change

Temperature change map of North America Areas of significant changes to Earth systems observed in North America over the last 20 years, represented by various symbols, are linked with areas of rising temperatures, noted in red. Credit: NASA
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A new NASA-led study shows that human-caused climate change has impacted a wide range of Earth's natural systems, from permafrost thawing to plants blooming earlier across Europe to lakes declining in productivity in Africa.

Cynthia Rosenzweig of NASA's Goddard Institute for Space Science in New York and scientists at 10 other institutions have linked physical and biological impacts since 1970 with rises in temperatures during that period. The study, published May 15 in the journal Nature, concludes that human-caused warming is resulting in a broad range of impacts across the globe.

"This is the first study to link global temperature data sets, climate model results, and observed changes in a broad range of physical and biological systems to show the link between humans, climate, and impacts," said Rosenzweig, lead author of the study.

Rosenzweig and colleagues also found that the link between human-caused climate change and observed impacts on Earth holds true at the scale of individual continents, particularly in North America, Europe, and Asia.
Photograph of a forest When permafrost melts, the layer of loose soil deepens and trees lose their foundations and tip over. Similar impacts across Earth are likely due to human-caused climate change. Credit: Jon Ranson

To arrive at the link, the authors built and analyzed a database of more than 29,000 data series pertaining to observed impacts on Earth's natural systems, collected from about 80 studies each with at least 20 years of records between 1970 and 2004. Observed impacts included changes to physical systems, such as glaciers shrinking, permafrost melting, and lakes and rivers warming. Impacts also included changes to biological systems, such as leaves unfolding and flowers blooming earlier in the spring, birds arriving earlier during migration periods, and ranges of plant and animal species moving toward the poles and higher in elevation. In aquatic environments such as oceans, lakes, and rivers, plankton and fish are shifting from cold-adapted to warm-adapted communities.

The team conducted a "joint attribution" study in which they showed, first, that at the global scale, about 90 percent of observed changes in diverse physical and biological systems are consistent with warming. Other driving forces, such as land use change from forest to agriculture, were ruled out as having significant influence on the observed impacts.

Next, the scientists conducted statistical tests and found that the spatial patterns of observed impacts closely match temperature trends across the globe, to a degree beyond what can be attributed to natural variability. So, the team concluded that observed global-scale impacts are very likely due to human-caused warming.

Satellite image of Siberia Impacts from warming are evident in satellite images showing that lakes in Siberia disappearing as the permafrost thaws and lake water drains deeper into the ground. Credit: NASA Earth Observatory
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"Humans are influencing climate through increasing greenhouse gas emissions and the warming is causing impacts on physical and biological systems that are now attributable at the global scale and in North America, Europe, and Asia," said Rosenzweig.

On other continents, including Africa, South America, and Australia, documentation of observed changes in physical and biological systems is still sparse despite warming trends attributable to human causes. The authors concluded that environmental systems on these continents need additional research, especially in tropical and subtropical areas where there is a lack of impact data and published studies.
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Global Warming Solution: Landfill Forests?

Graphic illustrating how burying forests might take carbon out of the atmosphere to solve global warming.
Photo: Wiley-VCH 2008

The whole problem with global warming starts with digging up and burning the carbon from plants and animals, in the form of coal and oil, that has been buried for millions of years.

So two German scientists have a solution: Start burying stuff on a massive scale.

The scientists, Fritz Scholz and Ulrich Hasse from the University of Greifswald, start with a common idea: Planting forests, which absorb carbon dioxide from the atmosphere. But instead of letting those trees stand (or worse burning or letting them decay so that the carbon is released to the atmosphere) the scientists have a novel suggestion. Landfill them.

By burying the trees from those deliberately planted forests, the scientists believe they might blunt the impact of global warming, or even negate all global emissions.

“For the first time, humankind will give something back to nature that we have taken away before,” says Scholz. “Whereas other environmental problems can, at least in principle, be solved by the appropriate modern technology, there are no realistic solutions for the CO2 problem.”

Disturbing soil, though, as analyses of farming and suburban sprawl have demonstrated over and over again, also releases carbon. To avoid this, the scientists suggest using old mines for their forest landfills.

One little problem with this miracle solution: The world would have to plant 3.8 million square miles of forest every year to counteract current global carbon dioxide emissions. That's bigger than the size of the United States (including Alaska and Hawaii). And the scientists themselves point out that it's equivalent to all virgin forests lost in the 20th century.

That's also a lot of tree landfill space.

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