The Synthesist: Climate Change Could Amp Up Ocean Noise
In recent honor of World Oceans Day, and what would have been Jacques Cousteau’s 100th birthday, and the thirty-fifth anniversary of “Jaws,” and not least because it was hot as all global warming outside, I sought refuge in “Oceans,” the majestic new documentary film by the directors of “Winged Migration” and “Microcosmos.” Only one theater within 300 miles was showing it, at only one showtime, and I caught it on what turned out to be the last day. As I sat all but alone in the fading light, my timing felt ominously apt. I’m always struck by how quiet ocean documentaries are. One hears the ghostly soundings of whales, of course, the eager pip of dolphins, the clacking of a crab’s claws. But invariably, as if to cover for an awkward and extended natural silence, the soundtrack swoops in, alternately dreamy and orchestral, with strings or harps or xylophones. In 1953 Cousteau called the ocean “the silent world”; six decades later, despite otherwise profound advances in cinematography, one would be forgiven for thinking he was right. But in that time science has come to understand that the sea brims with biological sound. Many if not most fish, for instance, communicate audibly. The croaker, the sea robin, and the sea trout seek mates and frighten enemies with honks and gurgles they produce with their swim bladders. The parrotfish, the garibaldi, the bar jack, and the scad grind their teeth with a rasping sound (think nails on chalkboard) to ward off intruders. The toadfish hoots like an owl, the cowfish barks like a dog; herring fart. The northern seahorse, in courtship, flicks a protuberance on its bony skull that clicks and snaps like a castanet. The black drum croaks so loudly in the canals of Florida that it can be heard through the ground and into the homes of nearby residents. Blame our senses for the oversight. Slaves to light, we forget that the vast majority of sea life resides in darkness, below the photic zone, and can’t rely on visual cues. And sound behaves differently underwater. Although high-frequency noise quickly attenuates, as the water absorbs it, low-frequency sounds, especially those between 10 to 200 Hz (roughly the range of bass guitar; humans can hear frequencies up to 20,000 Hz), can travel far, even miles. Sometimes BBC video crews ask Stephen Simpson, a reef biologist at the University of Bristol, to borrow some reef sounds for a film they’re making. He regrets to tell them that he has no stereo recordings, which can be played through two separate audio channels and sound great in a movie theater; sound travels too fast under water — five times faster than in air — to be audible in anything but mono. “It’s an alien acoustic environment,” Simpson says, “one we may not be ready for, I guess.” Coral reefs are particularly loud. Some noise comes from the wind and breaking waves, but most is low-frequency fish chatter and the collective claw-clicking of snapping shrimp, which sounds “like heavy rain on a tin roof,” Simpson says, and be can loud enough to impede the use of military sonar. Put it all together and you get “a pretty complex soundscape,” he notes. Indeed, Simpson has found that different reef habitats—barrier or fringing, mangrove or sandflat, pristine or degraded by sediment or overfishing — have different, identifiable audio signatures. Biologists traditionally study the health and diversity of reefs through visual surveys, which have their limitations — night, for instance. Lately Simpson has begun thinking that reef noise could be a useful monitoring tool. One could record several reefs in a day, for a quick overview, or leave the recording equipment out for months to collect long-term data. But reef noise isn’t a mere byproduct; it is instrumental in the reefs’ very formation, Simpson has found. Biologists have long wondered how young reef fish, which are cast into the open ocean as tiny larvae, manage to find their home reef days or weeks later. In a neat experiment a few years ago, Simpson set up two light traps, one quiet and the other crackling with the piped-in sounds reef fish and crustaceans. Larval fish were clearly more drawn to the latter. The reef noise is a homing beacon, Simpson says, “a roadmap that these organisms use to find their way.” In fact, reef fish are sensitive to sound even as embryos and become more sensitive to it, and in wider range of frequencies, as they develop. Nor is the phenomenon restricted to fish. Recently Simpson and some colleagues working in the Caribbean found that baby corals — mere flea-sized sacks of cells — orient by sound before settling into a hardened station on the reef. They can choose a direction and go. “When the idea was first suggested, I thought it was pretty out there,” Simpson concedes. “Look at it: it’s a blob covered in hair cells, it doesn’t have a central nervous system, an auditory apparatus, or anything.” But, he notes, those hair cells, or cilia, are akin to those in our own inner ear, where, when waggled by vibrating particles, they help detect sound. The cilia on coral larvae my serve the same purpose; they may even be tuned to specific frequencies. In effect, every larva is an inside-out ear; the reef literally broadcasts itself into existence. “Our instinct had been to assume that they’re pretty much pathetic,” Simpson says of the larvae. “But the more we learn, the more amazed we become. They can hear, smell, pick their habitats — they have control over their destiny.” Up to a point, sadly. Even as scientists expand their appreciation for the sea’s natural sounds, they have grown troubled by the rising tide of human-made noise. The deafening effect of seismic and sonar blasts on dolphins and whales is well documented. But low-frequency noise has become more pervasive too, especially near shore: more shipping traffic, more recreational boating, more underwater pile-driving. One recent study off the California coast found that underwater sound levels at the lowest frequencies have increased by an order of magnitude since the 1960s. How this aural fog might effect sea life is unclear. Could a rise in noise change where and how fish school, as traffic noise alters the flocking and nesting behavior of birds? Might it mask their ability to communicate, reproduce, seek prey and avoid predators — or, in the case of young corals, find their home reefs and build upon them? Or might they learn to hear around it, they way we acclimate to a noisy air-conditioner or the background din of a cocktail party. “When it comes to the chronic effects of sound,” Simpson says, “nobody has any real solid evidence.” Climate change will only raise the volume. As the ocean warms, it will become more acidic; that hinders animals like corals from forming carbonate shells. It also reduces the concentration of sound-absorbing chemicals like boric acid and magnesium sulphate, enabling low-frequency noise to travel farther, according to a recent study led by Tatiana Ilyina of the University of Hawaii at Honolulu. “The ocean,” Ilyina writes, “is becoming transparent to sound.” If that’s not enough, the ears of fishes may change too. Fishes rely on the otolith, a carbonate structure in the ear, to orient themselves and sense their surroundings. But a study last year from the Scripps Institution of Oceanography found that white sea bass reared in carbon-dioxide-rich water grow otoliths that are bigger than expected. It’s not yet clear if the size difference affects function, but symmetry does. In a separate study, Simpson recently found that reef fishes with asymmetrical otoliths have a harder time hearing the preferred sounds of their reef. The fish face a kind of tinnitus, from without and within. The seas are in trouble. One need only watch a few minutes of video of the Deepwater oil disaster, streaming live courtesy of a remotely operated submersible vehicle, to grasp the scale of the harm we wreak. Through the artistry of film, we can marvel at the sea life that whose grace and beauty we may soon forever miss. The shame — one of many — is we may never truly hear it.
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The Synthesist: Climate Change Could Amp Up Ocean Noise
Chicago Plants the World’s Largest Urban Solar Farm
Chicago’s sprawling south side, once thrumming with steel mills and factories, is now covered by large swaths of weedy land strewn with the rubble of faded industries. But last year, a 40-acre patch not far from what was once home to the famous Pullman rail car factory sprouted a crop of 32,000 solar panels. The photovoltaic arrays move automatically to follow the sun, a glistening aberration in an otherwise drab and decrepit landscape. This is the country’s — and perhaps the world’s — largest "urban solar farm," and since December it has been generating up to 10 megawatts of clean electricity to help power a metropolis better known for its archaic dirty coal plants. Industry executives, environmentalists, and city officials — who don’t always find themselves on the same side of an issue — hope it will inspire other solar plants throughout polluted Rust Belt cities. Today Chicago Mayor Richard Daley and Exelon CEO John Rowe will lead an official unveiling of the plant. Daley has touted it as part of the city’s plan to take action on climate change and hailed it as a job creator in tough economic times. The Chicago plant hired a handful of permanent employees and about 200 union construction jobs, 44 percent of which were awarded to minorities. Large solar plants of 5 megawatts or more are common in Europe and the southwestern United States but usually aren’t built in highly populated areas. Denis Lenardic, the Slovenia-based editor of widely respected annual reports on the solar industry, said the Chicago project is likely the largest of its kind in the world. Advocates hope the Chicago project shows that solar plants don’t have to be massive and remote — they can be built on abandoned industrial sites or unused land owned by water treatment plants. Putting solar plants close to transmission lines and power users is highly efficient and improves the availability of power for local users in case of downed lines or other problems on the grid. Though not as sunny as the American southwest, the Chicago area’s solar resources are roughly equivalent to or even better than those of Germany and Spain, the world leaders in solar generation. The swiveling panels at the Chicago plant, built by SunPower Corp. and billed as "the most powerful on the planet," generate 30 percent more energy than typical fixed-base panels. The Chicago plant’s maximum capacity of 10 megawatts isn’t much in the larger scheme of things — enough for just 1,500 homes in a city of three million. And during the winter, generation is usually below capacity. But proponents would like to see a host of similar solar farms peppering pockets of empty land in metropolitan areas, providing 5 megawatts here, 10 megawatts there, adding up to a significant energy output. SunPower vice president of public policy Julie Blunden describes them as potential "urban infill." Neighbors of the south side plant say they are thrilled with the investment and symbol of green energy in their back yard. "You hear so much about NIMBYism, here we actually got YIMBYism. We were very welcomed by the community," Blunden said. "We came in and provided clean energy and some jobs, using local labor and local steel." As clean energy has become more desirable and cost-competitive, solar panels have sprouted on the rooftops of houses, government buildings, and big box stores in major cities. This type of solar power is called "distributed generation," with panels providing electricity for a given building or complex and often sending energy back to the grid if the panels generate more than the building uses. Solar plants, by contrast, generate electricity that goes directly to the grid and is sold by a local utility. In northern Illinois, the electricity from Exelon plants is distributed by ComEd. Illinois previously got just 3.3 megawatts of electricity from solar, meaning the Exelon project increased state solar capacity four-fold. Solar generation is driven in part by state renewable energy portfolio standards. Illinois’s standard mandates that 25 percent of the state’s electricity must be generated from renewable sources such as wind and solar by 2025. Six percent of that must come from solar by 2015. That would mean about 750 megawatts of solar power, or more than 70 plants like the south side one in the next five years. The Illinois Power Agency, a government body, is responsible for buying power from different generation companies to make sure that the state complies with the RPS. But larger-scale projects like the one on Chicago’s south side will only become commonplace if they end up being cost-effective, experts say. Exelon was counting on three types of government incentives to make the Chicago solar plant viable. A federal loan guarantee fell through, but company officials say they are still committed to the plant as an experimental "demonstration project." Whether they would build more in the future remains to be seen. "The economics are such that we need the federal incentives," said Exelon senior vice president Tom O‘Neill. "Without these incentives, the cost structure exceeds the revenue." Henry Henderson, director of the Natural Resources Defense Council’s Midwest program, said it’s only logical that the government back clean energy. Coal-fired power plants might seem cheaper, but actually, fossil fuels such as coal come with all kinds of hidden costs in the form of air pollution, human health problems, and global warming, he said. Henderson appreciates the symbolism of cutting- edge energy generation on the city’s now-ragged far south side, which once produced luxury rail cars for the nation. "Pullman was very innovative in its time," he said. "This is a way of doing something innovative now within a place that drove the transformation of our transportation system in the 19th century. How do we take that legacy and turn it into a point of productivity again? It’s recycling at the most important scale."
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Chicago Plants the World’s Largest Urban Solar Farm
‘Carbon Trees’ Would Suck CO2 Out of Air and Into Your Soda
Carbon dioxide is one of the most plentiful gases in the atmosphere, but when soda makers want to inject the fizz into their sweet-tasting drinks, they often have to pay through the nose for it. Many bottlers buy CO2 that was created as a byproduct of industrial processes, paying up to $300 per ton for the gas. So what if instead of relying on CO2 shipped via tanker trucks, soda makers could snare the gas right out of the air with a forest of roof-mounted synthetic "trees" — cutting their costs and helping reduce greenhouse gas pollution at the same time? That’s the vision of Billy Gridley, CEO of Global Research Technologies (GRT), a New York-based startup that is working to make prototypes of these high-tech devices commercially viable. Not long ago, few scientists believed it was possible to extract CO2 out of the atmosphere in a way that could be profitable. The barrier? Most methods of CO2 extraction consume enormous amounts of energy and require trucks or pipelines to ship the CO2 where it’s needed, which gets prohibitively expensive. GRT sees a way around those problems: create a device to capture the CO2 where it’s needed. The company has devised a lower-energy approach that Gridley says can capture CO2 cheaply enough to supply commercial buyers of the gas. The devices are called "carbon trees" because they mimic the carbon dioxide-absorbing abilities of real trees. In time, Gridley believes, GRT’s technology will be ready to help meet the huge challenge if Congress or the Environmental Protection Agency dictate that CO2 emissions must be captured and stored permanently as a potential solution to climate change. For now, GRT’s breakthrough looks less like a tall tree than a single fuzzy branch, one that’s connected to hodgepodge of tubes, compressors and other gizmos. GRT unveiled a working demonstration setup at last December’s meeting of the American Geophysical Union in San Francisco. By proving the viability of its technology, GRT created hope in climate science circles that "air capture" could yet emerge as a viable economic option to reduce global warming pollution. Above: GRT demonstrated its air capture technology at the American Geophysical Union conference last December. Photo: Molly Samuel, KQED.org Their prototype stands out because today no other system is being commercialized to capture CO2 out of ambient air. Others are focusing instead on industrial emissions. Backed by billions in public subsidies, engineering leaders such as Alstom, GE, and Siemens are racing to standardize systems that can snare the greenhouse gas exhaust from cement kilns, steel mills, and power plants, where CO2 levels are much higher than in the atmosphere. More than half of global greenhouse gas emissions come from such "stationary" sources. Utility executives describe the challenge of developing these systems as something like retrofitting a chemical plant on the back of a power plant. And once captured from power plants and factories, the CO2 will have to be trucked or piped away, either to markets where it can be sold, or to geological formations where it can be buried. Creating such a CO2 network, critics argue, will be on par with replicating the nation’s natural gas pipeline system — a 213,000-mile-long network that was built more than a century ago. GRT’s approach promises to eliminate much of this costly distribution infrastructure. Consider a McDonald’s today. "To carbonate beverages at the soda fountain, every week or so a truck rolls up to refill their CO2 supply," says Gridley. "A GRT unit (on the roof of the restaurant) could eliminate all those trucks, and all the fuel needed to deliver the CO2." The seed of GRT’s project to build synthetic trees took root in 2004, as a breakthrough made by Klaus Lackner, a geophysicist at Columbia University. Conventional CO2-capturing approaches rely on some combination of chemical additives, heat, and pressure to process CO2. But Lackner began toying with a class of materials that he knew had a chemical propensity to lock up CO2 on their surface. Lackner’s insight was part luck, part hunch. The twist was realizing that an increase in humidity — rather than energy-hogging shifts in heat or pressure — could get the material to exhale its captured CO2. "I didn’t quite believe it when I got it to work the first time," he says. Another cost-savings plus: the material Lackner identified is commonly available as a resin, or plastic, that can perform thousands of capture-and-release cycles. GRT’s first commercial version will look more like a merry-go-round than a tree. The entire device is designed to be packed into a standard shipping container, making it easy to transport. When set up, door-sized panels made of Lackner’s special resin are hung on a carousel that will rotate slowly, exposing them to CO2 as they go round. Upon completing a revolution, a panel is automatically retrieved from the carousel and pulled into a chamber where it is wetted to release the stored CO2. The filter is then returned to the carousel for another rotation. Above: Artist’s rendering of commercial air capture system. Courtesy GRT The process generates a stream of "dilute CO2," as much as 250 times more concentrated than in the atmosphere, at concentrations of about 5 to 10 percent. To generate pure CO2, the panels can be wetted in a vacuum — a step that can double or triple adds costs. Someday, Lackner imagines, this extraction step could be performed inside tree-like towers designed to automatically seal, extract the CO2, and then reopen once the gas is piped away. "The taller the structures are, and the more surface area they have, the more CO2 they’ll capture," says Lackner. First on GRT’s hit list of potential customers are those with an appetite for dilute CO2: agricultural and biofuel players such as greenhouses and algae farms, which need large volumes of dilute CO2 to feed to their plants. Algae farms are emerging as a source of renewable biofuels, such as bio-diesel or "green gasoline." In these markets, GRT anticipates selling dilute CO2 at $50 to $75 per ton. (In December, as part of $564 million grant for biofuels development, the U.S. Energy Department directed $125 million to five algal-fuel projects). GRT’s other early-stage target includes the $1-2 billion market for pure CO2, such as producers of carbonated drinks and dry ice. Trucking costs can drive up prices for pure CO2 to $300 per ton for customers the farthest away from the source. In both these arenas, GRT plans to deliver cost-competitive CO2 by 2012. GRT’s next step would be to sell to very-high volume buyers. Today’s biggest market for CO2 is in the United States’ "oil patch," where drillers pump liquefied CO2 under high pressure into aging wells to drive more oil out of them. In Texas and the Southwest, the center of this "enhanced oil recovery" industry, drillers tap into natural reservoirs of CO2 in the earth and ship them to oil fields via pipeline. It’s roughly a $10 billion market today, where some 40 million tons of pure CO2 is bought annually. As the price of oil goes up, the thirst for CO2 rises; even at current prices, today’s CO2 supplies can’t meet demand. Gridley figures that if GRT can drive down its costs to $50 per ton of pure CO2, demand from oil drillers could be worth tens of billions of dollars annually. All this depends, of course, on whether GRT can successfully drive down the price of its systems. Standardizing the design is the key to reducing costs. "It’s like manufacturing cars," says Lackner. "Build one by hand, and it’s expensive. But build thousands on an assembly line, and the per-unit cost falls dramatically." Today, as GRT debugs its prototype to launch one-off mobile units next year, Lackner estimates the price for a single rig would be around $200,000. If GRT can scale up to supply the oil patch markets, he predicts large-scale manufacturing would drive the price down to a car-like $20,000 per unit. Farther out, the biggest opportunity of all for carbon capture players could be U.S. or global carbon markets. By 2020, if Kyoto-style regulations to control greenhouse gas pollution are adopted in the United States, Gridley estimates that some 2,000 million tons of CO2 would have to be captured and sequestered annually — potentially a $40 billion business. By that time, Gridley hopes GRT’s air capture technology will be among the lowest-cost options for companies looking to meet the new rules. But the company must first prove that it can supply today’s soda makers with something closer to one ton per day. In the past year, GRT relocated from Arizona to New York City, where Lackner is building a research team at Columbia University to advance the basic science of air-capture technology. Gridley, meanwhile, is focusing on developing and contracting out the company’s first fully-integrated prototype. He’s also hunting for venture capital to fund commercial development of the company’s first round of commercial units, scheduled to roll out in 2011.
More here: ‘Carbon Trees’ Would Suck CO2 Out of Air and Into Your Soda