EFE

Firefighters battled wildfires that spread quickly in parched forests in Colorado and New Mexico, forcing hundreds of people from their homes and the evacuation of wolves from a sanctuary.

In the modern global climate, higher levels of carbon dioxide (CO2) in the atmosphere are associated with rising ocean temperatures. But the seas were not always so sensitive to this CO2 “forcing,” according to a new report. Around 5 to 13 million years ago, oceans were warmer than they are today – even though atmospheric carbon dioxide concentrations were considerably lower.

The unusual mismatch between sea temperatures and CO2 levels during this time period hints that the relationship between climate and carbon dioxide hasn’t always been the same as it is today, said Petra Dekens, assistant professor of geosciences and a co-author of the new study published in the journal Nature.

“There was a transition, from the Earth’s climate system being not as sensitive to changes in atmospheric carbon dioxide to becoming more sensitive to these changes,” Dekens said. “What’s interesting is that we can see this transition happening within the last 13 million years.”

The connection between modern-day ocean warming and increased levels of atmospheric carbon dioxide produced by human activities has been confirmed in numerous studies, many of them collected in the most recent report of the Intergovernmental Panel on Climate Change.

Recent reconstructions of carbon dioxide levels for the late Miocene time period (roughly 5 to 13 million years ago) suggest that CO2 concentrations for the period were only 200-350 parts per million. Modern CO2 concentrations, by contrast, are around 390 parts per million.

The study’s lead author, Jonathan P. LaRiviere at the University of California, Santa Cruz, and colleagues including Dekens, sought information on late-Miocene ocean temperatures to analyze alongside the Miocene CO2 reconstructions.

They used an organic compound called unsaturated alkenone as their “fossil thermometers.” The compound is produced by tiny phytoplankton and preserved in cores of ocean sediment drawn from the mid-latitude Pacific Ocean basin. Ratios of the compound preserve a record of the water temperature in which the plankton lived.

These data provide the first evidence, Dekens said, that late Miocene sea surface temperatures were significantly warmer than today across a large swath of the North Pacific. The research team found that sea surface temperatures appeared to be highest in the early part of the late Miocene (around 12 to 13 million years ago), and gradually cooled throughout the late Miocene.

The researchers also looked at changes in the late Miocene thermocline, or the ocean layer where warmer, shallow waters meet colder, deeper waters. By comparing oxygen isotope data retrieved from a variety of fossil plankton species that thrive at different ocean depths, they found that the depth of the thermocline has been growing shallow over the past 13 million years.

It is possible, Dekens and colleagues suggest, that changes in the thermocline played some role in creating the warmer waters of the late Miocene – even as carbon dioxide concentrations stayed relatively low.

The depth of the thermocline affects the mixing and circulation of colder and warmer ocean waters, which can in turn affect ocean temperature and atmospheric temperatures in a complex feedback cycle.

“We would like to have more records from different regions,” Dekens said, “to see if this change in the depth of the thermocline was a global change.”

The thermocline might have grown shallow, the researchers say, as massive ocean waterways opened and closed with the shifting of tectonic plates. These changes would have remodeled ocean basins and the major patterns of ocean circulation.

One major waterway that began to close during the period was the Central American Seaway, an ancient body of water separating North and South America. The seaway was later closed by the volcanic creation of the Panama isthmus.

The study published in the June 7 issue of Nature. LaRiviere and Dekens’ co-authors include A. Christina Ravelo and Heather L. Ford of the University of California, Santa Cruz; Allison Crimmons of the U.S. Environmental Protection Agency; Mitch Lyle of Texas A and M University; and Michael W. Wara of Stanford Law School.

Using scientific theories, toy ecosystem modeling and paleontological evidence as a crystal ball, 18 scientists, including one from Simon Fraser University, predict we’re on a much worse collision course with Mother Nature than currently thought. In Approaching a state-shift in Earth’s biosphere, a paper just published in Nature, the authors, whose expertise span a multitude of disciplines, suggest our planet’s ecosystems are careening towards an imminent, irreversible collapse.

Earth’s accelerating loss of biodiversity, its climates’ increasingly extreme fluctuations, its ecosystems’ growing connectedness and its radically changing total energy budget are precursors to reaching a planetary state threshold or tipping point.

Once that happens, which the authors predict could be reached this century, the planet’s ecosystems, as we know them, could irreversibly collapse in the proverbial blink of an eye.

“The last tipping point in Earth’s history occurred about 12,000 years ago when the planet went from being in the age of glaciers, which previously lasted 100,000 years, to being in its current interglacial state. Once that tipping point was reached, the most extreme biological changes leading to our current state occurred within only 1,000 years. That’s like going from a baby to an adult state in less than a year,” explains Arne Mooers. “Importantly, the planet is changing even faster now.”

The SFU professor of biodiversity is one of this paper’s authors. He stresses, “The odds are very high that the next global state change will be extremely disruptive to our civilizations. Remember, we went from being hunter-gathers to being moon-walkers during one of the most stable and benign periods in all of Earth’s history.

“Once a threshold-induced planetary state shift occurs, there’s no going back. So, if a system switches to a new state because you’ve added lots of energy, even if you take out the new energy, it won’t revert back to the old system. The planet doesn’t have any memory of the old state.”

These projections contradict the popularly held belief that the extent to which human-induced pressures, such as climate change, are destroying our planet is still debatable, and any collapse would be both gradual and centuries away.

This study concludes we better not exceed the 50 per cent mark of wholesale transformation of Earth’s surface or we won’t be able to delay, never mind avert, a planetary collapse.

We’ve already reached the 43 per cent mark through our conversion of landscapes into agricultural and urban areas, making Earth increasingly susceptible to an environmental epidemic.

“In a nutshell, humans have not done anything really important to stave off the worst because the social structures for doing something just aren’t there,” says Mooers. “My colleagues who study climate-induced changes through the earth’s history are more than pretty worried. In fact, some are terrified.”

Study predicts imminent irreversible planetary collapse
Coming from Chile, Canada, Finland, the United Kingdom, Spain and the United States, the authors of this paper initially met at the University of California Berkeley in 2010 to hold a trans-disciplinary brainstorming session.

They reviewed scores of theoretical and conceptual bodies of work in various biological disciplines in search of new ways to cope with the historically unprecedented changes now occurring on Earth.

In the process they discovered that:

+ Human-generated pressures, known as global-scale forcing mechanisms, are modifying Earth’s atmosphere, oceans and climate so rapidly that they are likely forcing ecosystems and biodiversity to reach a critical threshold of existence in our lifetime.

+ “Global-scale forcing mechanisms today “include unprecedented rates and magnitudes of human population growth with attendant resource consumption, habitat transformation and fragmentation, energy production and consumption, and climate change,” says the study.

+ Human activity drives today’s global-scale forcing mechanisms more than ever before. As a result, the rate of climate change we are seeing now exceeds the rate that occurred during the extreme planetary state change that tipped Earth from being in a glacial to an interglacial state 12,000 years ago. You have to go back to the end of the cataclysmic falling star, which ended the age of dinosaurs, to find a previous precedent.

+ The exponentially increasing extinction of Earth’s current species, dominance of previously rare life forms and occurrence of extreme climate fluctuations parallel critical transitions that coincided with the last major planetary transition.

When these sorts of perturbations are mirrored in toy ecosystem models, they tip these systems quickly and irreversibly.

The authors recommend governments undertake five actions immediately if we are to have any hope of delaying or minimizing a planetary-state-shift. Arne Mooers, an SFU biodiversity professor and a co-author of this study, summarizes them as follows.

“Society globally has to collectively decide that we need to drastically lower our population very quickly. More of us need to move to optimal areas at higher density and let parts of the planet recover. Folks like us have to be forced to be materially poorer, at least in the short term. We also need to invest a lot more in creating technologies to produce and distribute food without eating up more land and wild species. It’s a very tall order.”

Graphene has caused a lot of excitement among scientists since the extremely strong and thin carbon honeycomb-shaped material, just one atom thick, was discovered in 2004. In 2011, NASA’s Spitzer Space Telescope spotted the signature of flat carbon flakes, called graphene, in space –the first-ever cosmic detection of the material — which is arranged like chicken wire in flat sheets that are one atom thick.

The team of astronomers using Spitzer identified signs of the graphene in two small galaxies outside of our own, called the Magellanic Clouds, specifically in the material shed by dying stars, called planetary nebulae. The N 70 nebula shown above is a “Super Bubble” in the Large Magellanic Cloud (LMC image below), a satellite galaxy to the Milky Way system, located in the southern sky at a distance of about 160,000 light-years.

The infrared-sensing telescope also spotted a related molecule, called C70, in the same region – marking the first detection of this chemical outside our galaxy. According to the astronomers, the graphene and C70 might be forming when shock waves generated by dying stars break apart hydrogen-containing carbon grains.

Physicist Peter Horava, at the University of California, Berkeley, thinks graphere can help us understand what happened immediately after the big bang or what’s going on near the event horizon of black holes, where the gravitational fields are massive.

Letizia Stanghellini and Richard Shaw, members of the team at the National Optical Astronomy Observatory in Tucson, Arizona, describe how collisional shocks powered by the winds from old stars in planetary nebulae could be responsible for the formation of fullerenes (C60 and C70) and graphene (planar C24). The team was led by Domingo Anibal Garcia-Hernandez of the Instituto de Astrofisica de Canarias in Spain and includes international astronomers and biochemists.

Planetary nebulae originate from stars similar to our Sun that have reached the end of their lives and are shedding shells of gas into space. In this case, the planetary nebulae are located in the Magellanic Clouds, two satellite galaxies to our own Milky Way, that are best seen from the Southern Hemisphere. At the distance of the Magellanic Clouds, planetary nebulae appear as small fuzzy blobs.

However, unlike planetaries in our own Milky Way Galaxy whose distances are very uncertain, the distance to planetaries in the Magellanic Clouds can be determined to better than 5%. With such accurate distances, the research team determined the true luminosity of the stars and confirmed that the objects are indeed planetary nebulae and not some other object in the astrophysical zoo.

Fullerenes, or Buckyballs, are known from laboratory work on Earth and have many interesting and important properties. Fullerenes consist of carbon atoms arranged in a three dimensional sphere similar to the geodesic domes popularized by Buckminster Fuller.

The C70 fullerene can be compared with a rugby ball, while C60 is compared to a soccer ball. Both of these molecules have been detected in the sample. Graphene (planar C24) is a flat sheet of carbon atoms, one atom thick, that has extraordinary strength, conductivity, elasticity and thinness.

Cited as the thinnest substance known, graphene was first synthesized in the lab in 2004 by Geim and Novoselov for which they received the 2010 Nobel Prize in physics. “If confirmed with laboratory spectroscopy – something that is almost impossible with the present techniques – this would be the first detection of graphene in space,” said team member Garcia-Hernandez.

The team has proposed that fullerenes and graphene are formed from the shock-induced (i.e., grain-grain collisions) destruction of hydrogenated amorphous carbon grains (HACs). Such collisions are expected in the stellar winds emanating from planetary nebulae, and this team sees evidence for strong stellar winds in the ultraviolet spectra of these stars.

“What is particularly surprising is that the existence of these molecules does not depend on the stellar temperature, but on the strength of the wind shocks,” says Stanghellini.

The Small Magellanic Cloud is particularly poor in metals (any element besides hydrogen and helium, in astronomers’ parlance), but this sort of environment favors the evolution of carbon-rich planetary nebulae, which turns out to be a favorable place for complex carbon molecules.

The challenge has been to extract the evidence for graphene (planar C24) from Spitzer data. “The Spitzer Space Telescope has been amazingly important for studying complex organic molecules in stellar environments,” says Stanghellini.

“We are now at the stage of not only detecting fullerenes and other molecules, but starting to understand how they form and evolve in stars.” Shaw adds, “We are planning ground-based follow up through the NOAO system of telescopes. We hope to find other molecules in planetary nebulae where fullerene has been detected to test some physical processes that might help us understand the biochemistry of life.”

Meanwhile Horava, at the University of California, Berkeley, has developed a new theory of quantum gravity that reflects the need understand what happened immediately after the big bang or what’s going on near the event horizon of black holes, where the gravitational fields are massive.

In the physics of condensed matter, specifically in graphene, a carbon atom one atom thick, whose electrons ping around the surface like balls in a pinball machine and can be described using quantum mechanics. Because the graphene atoms are moving at only a fraction of the speed of light there is no need to take relativity into account.

But cool graphene down to near absolute zero and something extraordinary happens: the electrons speed up dramatically. Now relativistic theories are needed to describe them correctly. It was this change that sparked Horava’s imagination. What struck Horava about graphene is that Lorentz symmetry isn’t always apparent in it.

Could the same thing be true of our universe, he wondered. What we see around us today is a cool cosmos, where space and time appear linked by Lorentz symmetry – a fact that experiments have established to astounding precision. But things were very different in the earliest moments. What if the symmetry that is apparent today is not fundamental to nature, but something that emerged as the universe cooled from the big bang fireball, just as it emerges in graphene when it is cooled?

Horava tweaked Einstein’s equations in a way that removed Lorentz symmetry: a property that keeps the speed of light constant for all observers, no matter how fast they move, time slows and distances contract to exactly the same degree. This led Horava to a set of equations that describe gravity in the same quantum framework as the other fundamental forces of nature: gravity emerges as the attractive force due to quantum particles called gravitons, in much the same way that the electromagnetic force is carried by photons. He also amended general relativity to include a preferred direction for time, from the past to the future -the way the universe as we observe it appears to evolve.

“All of a sudden, you have new ingredients for modifying the behaviour of gravity at very short distances,” Horava said in an interview with New Scientist.

By breaking asunder the symmetry between space and time, Horava’s theory alters the physics of black holes – especially microscopic black holes, which may form at the very highest energies, which means for the formation of these black holes, and whether they are what they seem to be in general relativity “is a very big question.”

Horava gravity might also help solve one of the great unsolved mysteries of modern cosmology: the puzzle of dark matter if the equations of motion derived from general relativity are slightly off this could explain the observed speeds of the stars and galaxies without dark matter playing a role.
“It is possible that some fraction of the dark matter picture of the universe could be coming from corrections to Einstein’s equations,” Horava said.

Ditto for dark energy: theories of particle physics predict the strength of dark energy to be about 120 orders of magnitude larger than what is observed, and general relativity cannot explain this enormous discrepancy. But Horava’s theory contains a parameter that can be fine-tuned so that the vacuum energy predicted by particle physics is reduced to the small positive value that is in line with the observed motions of stars and galaxies.

The ultimate answers will come with Improved observations of supermassive black holes, which contain regions of intense gravity, which could reveal the necessary corrections to general relativity and prove Horava’s theory of quantum gravity, in much the same way that unexplained measurements of Mercury’s orbit showed that Newton’s laws were incomplete, opening the door for Einstein.

Researchers catalog more than 635,000 Martian craters

It’s no secret that Mars is a beaten and battered planet — astronomers have been peering for centuries at the violent impact craters created by cosmic buckshot pounding its surface over billions of years. But just how beat up is it?

Really beat up, according to a University of Colorado Boulder research team that recently finished counting, outlining and cataloging a staggering 635,000 impact craters on Mars that are roughly a kilometer or more in diameter.

As the largest single database ever compiled of impacts on a planet or moon in our solar system, the new information will be of help in dating the ages of particular regions of Mars, said CU-Boulder postdoctoral researcher Stuart Robbins, who led the effort. The new crater atlas also should help researchers better understand the history of water volcanism on Mars through time, as well as the planet’s potential for past habitability by primitive life, he said.

“This database is a giant tool that will be helpful in scores of future Mars studies ranging from age-dating and erosion to planetary habitability and to other applications we have not even thought of yet,” said Robbins, who is affiliated with CU-Boulder’s Laboratory for Atmospheric and Space Physics. “In a sense it’s like building a new and better hammer, which quickly becomes used by everyone.”A paper on the subject by Robbins and CU-Boulder faculty member Brian Hynek appeared last week in the Journal of Geophysical Research – Planets, a publication of the American Geophysical Union. A companion study by the two CU researchers was published in a recent issue of the same journal. The study was funded by NASA’s Mars Data Analysis Program.

The assembly of the new Mars crater database was tedious, said Robbins. “We have all this new information coming from Mars orbiters and landers that have helped generate far better maps illustrating the planet’s topography and surface details. I basically analyzed maps and drew crater rim circles for four years.”

Hynek, a LASP research associate and assistant professor in the geological sciences department, said knowing more about the history and extent of Martian cratering has implications for better understanding the potential for past life on Mars.

“Many of the large impact craters generated hydrothermal systems that could have created unique, locally habitable environments that lasted for thousands or millions of years, assuming there was water in the planet’s crust at the time,” said Hynek. “But large impacts also have the ability to wipe out life forms, as evident from Earth’s dinosaur-killing Chicxulub impact 65 million years ago.”

Robbins said most of the smaller diameter craters on Mars are younger than the largest craters and form the bulk of the planet’s crater population. “The basic idea of age dating is that if a portion of the planet’s surface has more craters, it has been around longer,” said Robbins. Much of the planet has been “resurfaced” by volcanic and erosional activity, essentially erasing older geological features, including craters.

The new database also is expected to help planetary scientists better understand erosion on the planet, said Robbins, who earned his doctoral degree from CU-Boulder’s astrophysical and planetary sciences department. “Our crater database contains both rim heights and crater depths, which can help us differentiate between craters that have been filled in versus those that have eroded by different processes over time, giving us a better idea about long-term changes on the planet’s surface.”

Having a better handle on the size and distribution of Martian impact craters also has implications for future, manned missions to the planet, said Hynek. NASA wants to know where the craters are and their particular features both from a safety and research standpoint. “Craters act as a ‘poor man’s drill’ that provide new information about the subsurface of Mars,” he said.

Since the most complete databases of lunar craters include only those roughly 10 to 15 kilometers in diameter or larger, and databases on Mercury’s craters contain only those over roughly 20 kilometers in diameter, it is difficult to compare them with the Martian crater database, said Robbins. While there are only about 150 to 200 known impact craters left on Earth, both the moon and Mercury are still peppered with craters due to their lack of atmosphere and plate tectonic activity, he said.

Cataloging the cratering of Mars and the moon is helping scientists understand a time a few hundred million years after the inner solar system formed, including an event about 3.9 billion years ago known as the “Late Heavy Bombardment” in which asteroids as large as Kansas rained down on Earth. “Although Earth has lost most of its geologic record due to tectonic plate movements and erosion, understanding the impact crater history on the moon and Mars can help us reconstruct our early days,” said Hynek.

Provided by University of Colorado at Boulder

An excavation is underway thanks to the discovery of the bones of a prehistoric mammoth in one Oskaloosa, Iowa, family’s backyard.

According to ABC’s affiliate ABC5-WOI in Des Moines, the first bones were discovered in July 2010 by a man named John and his two teenage sons when they were walking in the woods of their property looking for blackberries.

One of his sons pointed out what he thought was a ball in the creek below to his family. Once they got closer, John, who has an interest in archeology, noticed a marrow line at the top of the object, said reporter ABC5-WOI reporter Katie Eastman, who interviewed the family.

Realizing this was no ball, the family dug out what has now been identified as a mammoth femur.

Despite discovering the bones nearly two years ago, the bones were brought to the University of Iowa for identification only last month, sparking the interest of Holmes Semken, professor emeritus of Geoscience.

Semken enlisted the help of volunteers from the University of Iowa as well as Iowa State University, to help to uncover the fossils lying six feet below the surface.

The University of Iowa Museum of Natural History is overseeing the project’s excavation and research.

“The size of this discovery is quite uncommon,” said Sarah Horgen, education coordinator at the museum. “It’s pretty exciting-partially because the mammoth is being discovered where it died. And we know that because we’re finding very large bones right alongside very small bones.”

Horgen says the mammoth is at least 12,000 years old, and was extinct by the end of the last ice age.

Horgen also noted that the mammoth’s discovery is not uncommon in Iowa, and that the museum has a working record of reported fossil discoveries around the state.

“The bones discovered could be 100,000 years old or more,” she said.

Two digs have been held so far. In addition to the bones found by the landowner, volunteers have since uncovered the mammoth’s feet bones, as well as its floating and thoracic ribs.

“The femur is about 4 feet long. The ribs of the diaphragm that move when you breathe are 2 and half feet each. The ribs that connect to the breast bone are 4 feet. You could use one for a walking cane,” Semken said.

But what will happen to the mammoth’s bones once they’ve been all dug up?

“The bones really belong to the land owner,” said Semken. “Our agreement with him is we get the science.”

Semken is interested in finding how the animal died, but more importantly, how it lived.

He plans on studying the pollen samples and seeds lodged within the bones, as well as the compound make up to understand the environment the mammoth lived in, what it fed on, where it fed in terms of grassland as opposed to forest.

Semken says the digs should progress through the summer. He plans to enlist the help of volunteers from William Penn College in Oskaloosa, the local county conservation board, as well as rock clubs around the state to partake in the digs.

“We’ll go as long as it takes,” said Semken, “We don’t know how widely scattered the bones are.”

“For us to work with somebody who’s so interested in these types of materials and has a working knowledge of what to look for has been really great,” Horgen added. “The landowner is clearly quite interested in the time period.”

The landowner could not be reached for comment.

Source: WOI/ABC News