BP vows to "vigorously defend" itself at US oil spill trial

CHICAGO: British energy giant BP vowed Tuesday to "vigorously defend" itself in court next week against US government claims for "excessive" fines in the 2010 Gulf of Mexico oil spill disaster.

Prosecutors shot back with a warning that they will be fighting for the stiffest penalties possible at a blockbuster trial which opens Monday with tens of billions of dollars at stake.

"The United States is fully prepared for trial," Wyn Hornbuckle, a spokesman for the US Department of Justice, told AFP.

"We intend to prove that BP was grossly negligent and engaged in willful misconduct in causing the oil spill."

The mammoth trial in a New Orleans, Louisiana federal courthouse consolidates scores of remaining lawsuits stemming from the worst environmental disaster to strike the United States.

The first phase of the trial will focus on liability for the April 20, 2010 explosion that sank the BP-leased Deepwater Horizon drilling rig off the coast of Louisiana.

The blast killed 11 people and unleashed millions of barrels of oil into the Gulf, blackening beaches in five states and crippling tourism and fishing industries.

It took 87 days to cap BP's runaway well in a tragedy that riveted the nation.

BP is fighting civil penalties which could amount to as much as $21 billion if gross negligence is found.

"Gross negligence is a very high bar that BP believes cannot be met in this case," Rupert Bondy, group general counsel at BP, said in a statement.

"This was a tragic accident, resulting from multiple causes and involving multiple parties."

In addition to fighting the federal government over environmental fines, BP is also seeking to shift some of the liability to its subcontractors, drilling rig operator Transocean and Halliburton, which was responsible for the well's faulty cement job.

BP pleaded guilty in November to criminal charges -- including felony manslaughter -- and agreed to pay a record $4.5 billion in criminal fines.

It reached a $7.8 billion settlement early last year that will cover the bulk of the outstanding private claims for economic loss, property damage and medical problems.

It has paid out $10 billion to businesses, individuals and local governments impacted by the spill and spent more than $14 billion on the response and cleanup.

BP also remains on the hook for billions in additional damages, including the cost of environmental rehabilitation.

But while it was willing to settle the civil charges on "reasonable terms" BP said it will not accept the US government's assertion of gross negligence, or its estimation of how much oil was spilled.

"Faced with demands that are excessive and not based on reality or the merits of the case, we are going to trial," Bondy said in the statement.

"We have confidence in our case and in the legal team representing the company and defending our interests."

In a preview of an argument that will not reach trial until the second phase begins later this year, BP said the official US government estimate that 4.9 million barrels of oil was unleashed from the runaway well was "overstated" by at least 20 percent.

"BP believes that a figure of 3.1 million barrels should be the uppermost limit of the number of barrels spilled that should be used in calculating a Clean Water Act penalty," it said.

Meanwhile, the judge overseeing the consolidated trial on Tuesday approved a $1 billion settlement for civil penalties against rig operator Transocean.

The decision came after a $400 million settlement of criminal penalties against the Swiss drilling giant was approved last week.

Transocean pleaded guilty to one criminal count of violating the Clean Water Act and agreed to pay the $400 million fine for negligence that led to the explosion of the Deepwater Horizon rig.

The $1 billion civil penalty is for fines related to the oil spilled into the Gulf.

It is also responsible for implementing measures to improve operational safety and emergency response capabilities at all their drilling rigs working in waters of the United States.

-AFP/ac

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PlayStation 4 should go all-in on cloud-streaming games

Based on the steady stream of rumors about Sony's upcoming next-gen living room console, it's widely expected that gamers will be spending at least part of their time playing games streamed directly over the Internet.

According to the Wall Street Journal and others, Sony's acquisition of streaming game provider Gaikai in 2012 set the stage for streaming game content, and the new Sony console, whatever it's called, will offer both streamed games and games played via traditional optical disc, purportedly older catalog titles for the former, and newer games via the latter.

A move to streaming games is a far-thinking idea, and one that would reduce the need for large amounts of local storage for fully downloaded games, as well as the need to manufacture, transport, and store physical game discs -- with games joining music and movies as media types moving away from being distributed through retail stores on disc.

The idea of streaming game content is one we've been playing with for some time. The best-known player in this space is OnLive, a PC-based service that runs game software on a remote server farm and then streams the action, in real time, to players interacting via a controller or mouse/keyboard combo. Since that service launched in 2010, we've been reasonably impressed with it, although it works better for some games than others (for example, casual or third-person action games work better than first-person games, which are more sensitive to even the slightest lag).

The biggest pushback (besides the fact that OnLive has struggled to succeed) is that streaming games are far too reliant on your broadband Internet connection, which can be flaky, slow, or sometimes out altogether. This, coupled with the lag already built into live cloud game delivery, is enough to potentially turn off consumers.

Legitimate concerns, to be sure, and I have no illusion that today's A-list games could all be converted to cloud streaming right now and deliver the same high level of visual quality. But, the discussion about Sony and Gaikai reminds me of a conversation I had at the 2011 E3 video game trade show with John Carmack, a PC gaming legend and the lead programmer behind classics such as Doom and Quake. I asked him about streaming games in general, and OnLive specifically, and this is what he said:

I've played the OnLive stuff and a lot of people have just enough technical knowledge to count it out for the wrong reasons. When you talk about having a 50ms ping, that does not invalidate the process. One of the points that I make is that if you take a lot of the console games out there, and you're playing with your wireless controller, going through your post-process TV, the games themselves often have multiple frames of latency.

You get an event, you pipeline an animation, and it goes to the render thread and the GPU. A lot of games have over 100ms of latency in them right now. Now it's true that adding latency is always bad, and with OnLive, you're adding a compression step and two transmit steps.

But the laws of physics do not guarantee this to be a bad idea. I don't necessarily think any of the current players will live to see the pot of gold at the end of this rainbow, but I'd say it's almost a foregone conclusion that five or ten years from now, that's going to be a significant marketplace.

From a raw technical standpoint, it has too many positives going for it. There are negatives, but a lot of times, people will accept a big negative for a much bigger win. And the win for convenience and managing your library is huge. And the win for publishers and developers -- zero piracy, instant patching, all that data gathering -- are strong advantages. I don't think it's the big thing next year, but I think it's coming.

Even if the next-gen PlayStation kicks off with only a nod to streaming games, the era of the physical disc is still winding down. The current
Xbox 360, PlayStation 3, and
Wii U all offer full game downloads (even if many of these consoles have limited onboard storage for full games), and a whole generation of media consumers already thinks of video and music as streaming products from Netflix, Spotify, and others, as opposed to something you get on a plastic disc.

The game publishers themselves would like nothing more than to kill disc-based gaming. Think of the fixed hard costs associated with manufacturing an optical disc, putting it in a box, loading it in a gas-guzzling truck, driving it to a store, placing it on a shelf, and waiting for a consumer to march in and buy it (to say nothing of the resale of used games, something game publishers hate). Many of these costs can be reduced in the future by digital distribution, both download and streaming -- not that gamers can expect to see any of the savings passed along to them.

Whatever new hardware is being announced by Sony later this week will surely include an optical drive, as will the inevitable Microsoft Xbox upgrade expected later this year. But if we take a look at the current state of laptops, there's something similar going on. Many popular models, from the
MacBook Air to almost every ultrabook, omit the once-ubiquitous DVD drive. Taken to its logical conclusion, this may be the last generation of living-room consoles that include support for physical game discs.

Sony's PlayStation event will be held in New York on February 20, starting at 3 p.m. PT/6 p.m. ET. You can tune in to the live blog here:

CNET's live coverage of Sony's event on Wednesday

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New Study Analyzes Heavy Metal Dancing

Parents may never understand their rock 'n' roll loving children, but scientists might. A study published online in arXiv this week seeks to explain the "mosh pit"—using physics.

To most scientists, heavy metal refers to elements on the lower end of the periodic table. But to Jesse Silverberg and Matt Bierbaum, doctoral students at Cornell University's department of Condensed Matter Physics, the aggressive music—and the violent dancing that accompanies it—could be a key to understanding extreme situations such as riots and panicked responses to disasters.

For the past two years, Silverberg and Bierbaum have studied "moshing," at heavy metal concerts, using theories of collective motion and the physical properties of gasses to better understand the chaos of metal fans' dancing.

Moshing, for those who have never attended a heavy metal show, is a form of dancing in which participants bump, jostle, and slam into one another. It's a form of social ritual that anthropologists have likened to spirit possession in its uncontrolled, dynamic, and often violent nature.

Silverberg and Bierbaum say it can also be understood by applying models of gaseous particles. As these particles float in groups, they too run, bash, and slam into each other, sending the elements flying in chaotic patterns.

"We are interested in how humans behave in similar excited states," said Silverberg, "but it's not exactly ethical to start a riot for research."

Extreme Physics

Mosh pits provided the scientists with a way to observe excited collective movement without causing undue injury or death. Analyzing hours of recorded footage from concerts and making multiple field trips to music clubs, Silverberg and Bierbaum recognized the particulate physical patterns in the mosh pit.

Further, they differentiated two distinct forms of heavy metal dancing: the "mosh pit" itself, which follows the gaseous pattern, and the "circle pit" (where dancers run, smash, and dance in a circular rotation) within it, which adheres to a vortex pattern of particulate behavior.

Based on these observations, they created an interactive computer model depicting the behavior.

Animal Instincts

"Herd animals behave in very similar spirit—what physicists call 'flocking' behavior," said Bierbaum. (See "The Genius of Swarms," from the July 2007 issue of National Geographic magazine.)

As with groups of flying birds or schooling fish, simple rules can be applied to individuals in large groups—like moshers—to understand what seems to be very complex behavior. This makes modeling possible, allowing computers to re-create immense numbers of actions in a matter of seconds. These models can then be used to design spaces that would minimize trampling or injury, or to tailor responses to disasters like fires.

"The lessons we've learned in mosh pits [could be used] to build better stadiums, or movie theaters," Silverberg said.

James Sethna, one of the researchers' advising professors, hastened to add that his students' forays into heavy metal science "didn't start out for reasons of creating safer stadiums. We did it because it was cool and we wanted to know if we could explain human behavior—albeit slightly intoxicated behavior—without having to use complex [models]."

A longtime heavy metal fan himself, Silverberg shared which band produced the best results: "Killswitch Engage ... always gets the crowd nuts. Although of course everyone has their own favorites."

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Report Fingers Chinese Military Unit in US Hacks

A Virginia-based cyber security firm has released a new report alleging a specific Chinese military unit is likely behind one of the largest cyber espionage and attack campaigns aimed at American infrastructure and corporations.

In the report, released today by Mandiant, China's Unit 61398 is blamed for stealing "hundreds of terabytes of data from at least 141 organizations" since 2006, including 115 targets in the U.S. Twenty different industrial sectors were targeted in the attacks, Mandiant said, from energy and aerospace to transportation and financial institutions.

Mandiant believes it has tracked Unit 61398 to a 12-story office building in Shanghai that could employ hundreds of workers.

"Once [Unit 61398] has established access [to a target network], they periodically revisit the victim's network over several months or years and steal broad categories of intellectual property, including technology blueprints, proprietary manufacturing processes, test results, business plans, pricing documents, partnership agreements, and emails and contact lists from victim organizations' leadership," the report says.

The New York Times, which first reported on the Mandiant paper Monday, said digital forensic evidence presented by Mandiant pointing to the 12-story Shangai building as the likely source of the attacks has been confirmed by American intelligence officials. Mandiant was the firm that The Times said helped them investigate and eventually repel cyber attacks on their own systems in China last month.

Peter Parks/AFP/Getty Images

The Chinese government has repeatedly denied involvement in cyber intrusions and Chinese Foreign Ministry spokesperson Hong Lei said today that the claims in the Mandiant report were unsupported, according to a report by The Associated Press.

"To make groundless accusations based on some rough material is neither responsible nor professional," he reportedly said.

Mandiant's report was released a week after President Obama said in his State of the Union address that America must "face the rapidly growing threat from cyber attack."

"We know hackers steal people's identities and infiltrate private e-mail. We know foreign countries and companies swipe our corporate secrets. Now our enemies are also seeking the ability to sabotage our power grid, our financial institutions, and our air traffic control systems. We cannot look back years from now and wonder why we did nothing in the face of real threats to our security and our economy," he said.

Though Obama did not reference China or any country specifically, U.S. officials have previously accused the Asian nation of undertaking a widespread cyber espionage campaign.

Referring to alleged Chinese hacking in October 2011, House Intelligence Committee Chairman Rep. Mike Rogers (R-Mich.) said in an open committee meeting that he did not believe "that there is a precedent in history for such a massive and sustained intelligence effort by a government agency to blatantly steal commercial data and intellectual property."

Rogers said that cyber intrusions into American and other Western corporations by hackers working on behalf of Beijing -- allegedly including attacks on corporate giants like Google and Lockheed Martin -- amounted to "brazen and widespread theft."

"The Chinese have proven very, very good at hacking their way into very large American companies that spend a lot of money trying to protect themselves," cyber security expert and ABC News consultant Richard Clarke said in an interview last week.

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Biofuel rush is wiping out unique American grasslands

Say goodbye to the grass. The scramble for biofuels is rapidly killing off unique grasslands and pastures in the central US.

Christopher Wright and Michael Wimberly of South Dakota State University in Brookings analysed satellite images of five states in the western corn belt. They found that 530,000 hectares of grassland disappeared under blankets of maize and soya beans between 2006 and 2011. The rate was fastest in South Dakota and Iowa, with as much as 5 per cent of pasture becoming cropland each year.

The trend is being driven by rising demand for the crops, partly through incentives to use them as fuels instead of food.

The switch from meadows to crops is causing a crash in populations of ground-nesting birds. One of the US's most important breeding grounds for wildfowl, an area called the Prairie Pothole Region, is also at risk, with South Dakota's crop fields now within 100 metres of the wetlands. "Half of North American ducks breed here," says Wright.

Bill Henwood of the Temperate Grasslands Conservation Initiative in Vancouver, Canada, says the results are distressing. "Exchanging real environmental impacts for the dubious benefits of biofuels is counterproductive," he says. "Last year's record drought in the corn belt all but wiped out the crops anyway."

Journal reference: PNAS, DOI: 10.1073/pnas.1215404110

If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication department first for permission. New Scientist does not own rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to.

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Football: Nani propels United into FA Cup quarter-finals

MANCHESTER, United Kingdom: Nani scored one and made the other as Manchester United beat Reading 2-1 to book their place in the FA Cup quarter-finals here on Monday.

The Portuguese winger was only brought on as a substitute because of a first-half injury to Phil Jones but he certainly made his mark with a powerful second-half strike before setting up Javier Hernandez with a pinpoint cross.

United will now face the winner of Chelsea and Middlesbrough in the quarter-finals as Alex Ferguson's side continue to challenge for trophies on three fronts despite a late scare when Jobi McAnuff pulled one back for Reading.

"I'm satisfied with the quality of our play," said Ferguson, who made eight changes to the side that drew 1-1 with Real Madrid in last week's Champions League clash.

"We should have punished them better though.

"At 2-0 you are never comfortable. Nani deserved to be man of the match, his contribution was terrific. I had a feeling he would win the match for us. We are at home in the next round and we would take that against anyone."

His Reading counterpart Brian McDermott took solace from the overall performance.

"We came to Manchester United and put on a good performance as well, and we're disappointed not to be coming away with a result," said McDermott, whose side face a crucial Premier League relegation clash with fellow strugglers Wigan next Saturday.

United had come flying out of the blocks and Danny Welbeck gave Reading keeper Adam Federici his first work of the night a minute later with a low strike that was pushed away.

The Reading keeper pulled off a good save in the 22nd minute to deny Tom Cleverley's low shot before getting back on his feet to turn away Ashley Young's timid strike from close range.

Jones, after his impressive man-marking job against Cristiano Ronaldo last week, could be a doubt for the return leg in March after injuring his ankle in a clash with McAnuff and Nani replaced him.

Adam Le Fondre gave United keeper David De Gea his first work of the night with a quick turn and shot that the United keeper saved.

Nani then got straight into the action with a rasping shot that beat Federici before cracking off the post and flying away from danger.

The winger then forced the Royals stopper into a decent save in first-half stoppage time with a long-range effort.

United started the second half like the first with Cleverley trying to drill a low effort through a crowd of players before Reading cleared.

A deflected header from Vidic off Sean Morrison had to be cleared off the line by Reading striker Noel Hunt who was playing with staples in a head wound after a clash with the Serbian defender in the first half.

Reading were being pinned back as van Persie replaced Young before Nani whizzed one by the post in the 65th minute.

The Portuguese winger was certainly out to prove a point after not making the starting line-up and when Antonio Valencia laid the ball to him in the area in the 69th minute, he took a touch before rifling the ball home for just his third of the season.

Le Fondre fired at De Gea within moments but the tie was all but put beyond the visitors in the 72nd minute when Nani crossed for Hernandez who headed in at the front post.

With nine minutes remaining, Chris Smalling failed to clear a cross and McAnuff pounced to pull one back for Reading but they could not get a second to force the replay as Le Fondre headed a corner just over in stoppage time.

-AFP/ac

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Asia chatter predicts increase in cost of Retina iPad Mini

Be careful what you wish for: a Retina iPad will add a lot of cost -- so a report claims.

(Credit:
Apple)

Chatter in Asia has it that the total cost of the iPad Mini could increase by almost a third -- though no word on whether that would impact price.

Commentary in Digitimes, which is close to the chain of component suppliers in Asia, said the jump to a Retina screen means adding costly display components.

If iPad mini adopts the Retina display, the dots per inch (DPI) will be higher and the brightness of the backlight modules will have to improve. This also means the number of LEDs used will...[increase the total cost] by more than 30% if it is equipped with the 7.9-inch Retina panel.

This commentary is similar to what Vinita Jakhanwal, a display analyst at IHS iSuppli, told CNET in November.

At that time, she said a Retina iPad Mini with a design identical to the current Mini would not have been possible. "They would have had to compromise on thickness and weight and price," she said.

But more than three months have passed since then. And it's not known if display technologies such as IGZO or some version of Low Temperature Polysilicon (LTPS) -- the latter used in the
iPhone 5 -- are beginning to address some of these display assembly challenges.

If those challenges are met, a Retina iPad Mini could potentially maintain its current design and even, possibly, its price, Jakhanwal said previously.

When Apple introduced the 9.7-inch Retina in March 2012, it maintained the same price.

The upcoming
Nexus 7, for example, is expected to have a Full HD display but maintain the same $199 starting price.

The 7-inch
tablet segment may account for 45 percent to 60 percent of total shipments this year, Digitimes said.

iPad Mini First Look: The teeny, tiny iPad

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Confirmed: Dogs Sneak Food When People Aren't Looking

Many dog owners will swear their pups are up to something when out of view of watchful eyes. Shoes go missing, couches have mysterious teeth marks, and food disappears. They seem to disregard the word "no."

Now, a new study suggests dogs might understand people even better than we thought. (Related: "Animal Minds.")

The research shows that domestic dogs, when told not to snatch a piece of food, are more likely to disobey the command in a dark room than in a lit room.

This suggests that man's best friend is capable of understanding a human's point of view, said study leader Juliane Kaminski, a psychologist at the U.K.'s University of Portmouth.

"The one thing we can say is that dogs really have specialized skills in reading human communication," she said. "This is special in dogs." (Read "How to Build a Dog.")

Sneaky Canines

Kaminski and colleagues recruited 84 dogs, all of which were more than a year old, motivated by food, and comfortable with both strangers and dark rooms.

The team then set up experiments in which a person commanded a dog not to take a piece of food on the floor and repeated the commands in a room with different lighting scenarios ranging from fully lit to fully dark.

They found that the dogs were four times as likely to steal the food—and steal it more quickly—when the room was dark. (Take our dog quiz.)

"We were thinking what affected the dog was whether they saw the human, but seeing the human or not didn't affect the behavior," said Kaminski, whose study was published recently in the journal Animal Cognition.

Instead, she said, the dog's behavior depended on whether the food was in the light or not, suggesting that the dog made its decision based on whether the human could see them approaching the food.

"In a general sense, [Kaminski] and other researchers are interested in whether the dog has a theory of mind," said Alexandra Horowitz, head of the Dog Cognition Lab at Barnard University, who was not involved in the new study.

Something that all normal adult humans have, theory of mind is "an understanding that others have different perspective, knowledge, feelings than we do," said Horowitz, also the author of Inside of a Dog.

Smarter Than We Think

While research has previously been focused on our closer relatives—chimpanzees and bonobos—interest in dog cognition is increasing, thanks in part to owners wanting to know what their dogs are thinking. (Pictures: How smart are these animals?)

"The study of dog cognition suddenly began about 15 years ago," Horowitz said.

Part of the reason for that, said Brian Hare, director of the Duke Canine Cognition Lab and author of The Genius of Dogs, is that "science thought dogs were unremarkable."

But "dogs have a genius—years ago we didn't know what that was," said Hare, who was not involved in the new research. (See pictures of the the evolution of dogs, from wolf to woof.)

Many of the new dog studies are variations on research done with chimpanzees, bonobos, and even young children. Animal-cognition researchers are looking into dogs' ability to imitate, solve problems, or navigate social environments.

So just how much does your dog understand? It's much more than you—and science—probably thought.

Selectively bred as companions for thousands of years, dogs are especially attuned to human emotions—and, study leader Kaminski said, are better at reading human cues than even our closest mammalian relatives.

"There has been a physiological change in dogs because of domestication," Duke's Hare added. "Dogs want to bond with us in ways other species don't." (Related: "Dogs' Brains Reorganized by Breeding.")

While research reveals more and more insight into the minds of our furry best friends, Kaminski said, "We still don't know just how smart they are."

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ChristianMingle Date Rape Victims Sought by Cops

A suspected rapist accused of sexually assaulting a woman he met on ChristianMingle.com may have used the dating site to prey on women while he traveled across the country, California police said today.

Sean Patrick Banks, 37, a former Navy sailor, used a fake name to contact a woman who he allegedly raped in November, cops in La Mesa, Calif., said. Investigators believe that he used additional aliases to contact other women on the popular website and police hope that if there are additional victims they will recognize Banks.

Banks lives in Del Mar, Calif., and is currently unemployed but previously "travelled frequently around various spots in the U.S." for work, widening the search for potential victims from Southern California to across the country, said La Mesa Police spokesman Lt. Matt Nicholass.

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"We're looking to see if there are any other victims," Nicholass told ABCNews.com. "We're trying to locate other victims who recognize him by his face, because they may not know his real name is Sean."

Cops accuse Banks of posing on the site as "Rylan Butterwood" and "Rylan Harbough."

His alleged use of fake names complicated police efforts to track him down after a La Mesa woman accused him of rape at her home in November on their first face-to-face date.

"La Mesa police tried to identify him for a couple of months," Nicholass said, adding that a break in the case came after ChristianMingle.com turned over computer records that helped cops identify Banks.

Banks was charged with two counts of rape and pleaded not guilty. He posted bond of $500,000 and was released. Calls to several numbers associated with Banks were not returned. Authorities did not know if he had obtained an attorney.

"We continue to assist the La Mesa police department with its investigation in every way possible. The safety and security of our members is extremely important to us," ChristianMingle.com said in a statement through spokeswoman Arielle Schechtman. "In addition to having experts manually review all profile content and photos, we have developed several proprietary, automated tools to ensure the highest possible level of safety and privacy for our communities."

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Wiping out top predators messes up the climate

Wiping out top predators like lions, wolves and sharks is tragic, bad for ecosystems – and can make climate change worse. Mass extinctions of the big beasts of the jungles, grasslands and oceans could already be adding to greenhouse gases in the atmosphere.

Trisha Atwood of the University of British Columbia in Vancouver, Canada, studied the effect of removing predator fish from ponds and rivers in Canada and Costa Rica. Across a range of ecosystems, climates and predators, she found a consistent pattern: carbon dioxide emissions typically increased more than tenfold after the predators were removed.

"It looks like predators in many types of ecosystems – marine and terrestrial as well as freshwater – can play a very big role in global climate change," she told New Scientist.

The widespread and dramatic ecological impacts of the loss of top predators are well known. In the ensuing "trophic cascade", the vanished top predator's prey proliferate, which in turn puts pressure on the species that the prey eats, and so on down the food chain. In this way, changes at the top of a food chain destabilise the balance of populations right the way down.

But the geochemical impacts of trophic cascades, including any impact on emissions from ecosystems, are much less well known. Atwood's study of freshwater ecosystems showed how changes to species at the bottom of the food chain, such as photosynthesising algae, following the removal of a top predator dramatically increased the flow of CO₂ from the ecosystem to the atmosphere.

The effect will not always be to increase CO₂ emissions, however – sometimes the loss of top predators could decrease emissions, she says. "But we show that something so seemingly unrelated, like fishing all the trout from a pond or removing sharks from the ocean, could have big consequences for greenhouse-gas dynamics."

Help from kelp

Other recent studies have hinted at similar effects. Last October, Christopher Wilmers of the University of California, Santa Cruz, reported how the disappearance of sea otters is linked with increased CO₂ emissions from North American coastlines (Frontiers in Ecology and the Environment, doi.org/khz). With no otters eating them, sea urchins thrive and eat out kelp forests – often known as the "rainforests of the oceans" – resulting in major CO₂ releases.

Global climate models do not take such impacts into account yet. Atwood says they could be major, as freshwater emissions may be on a par with the influence of deforestation, which is thought responsible for around 15 per cent of human-caused CO₂ emissions.

Environmentalists will herald the findings as further evidence that it is vital to protect pristine habitats and the charismatic species at the top of their food chains. But there is a dark side. A recent study found that some island ecosystems around New Zealand store 40 per cent more carbon than others because of their top predators – invading rats that are wiping out seabird colonies. Rats, it seems, are good for the climate (Biology Letters, doi.org/bbmtw9).

Journal reference: Nature Geoscience, DOI: 10.1038/NGEO1734

If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication department first for permission. New Scientist does not own rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to.

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