venerdì 29 agosto 2008

trashmap



http://www.naturalhistorymag.com/1103/1103_feature.html

Ocean Surface Current Simulator (OSCURS) model developed by W. James Ingraham Jr., an oceanographer at the National Oceanic and Atmospheric Administration (NOAA), predicts the trajectory of drift originating along the coasts of the North Pacific rim. Drift from Japan is shown in red; drift from the United States, in blue. The diagrams show the position of drift after 183 days (top), three years (middle), and ten years (bottom).

The world's rubbish dump: a garbage tip that stretches from Hawaii to Japan

http://www.independent.co.uk/environment/the-worlds-rubbish-dump-a-garbage-tip-that-stretches-from-hawaii-to-japan-778016.html

A "plastic soup" of waste floating in the Pacific Ocean is growing at an alarming rate and now covers an area twice the size of the continental United States, scientists have said.
The vast expanse of debris – in effect the world's largest rubbish dump – is held in place by swirling underwater currents. This drifting "soup" stretches from about 500 nautical miles off the Californian coast, across the northern Pacific, past Hawaii and almost as far as Japan.
Charles Moore, an American oceanographer who discovered the "Great Pacific Garbage Patch" or "trash vortex", believes that about 100 million tons of flotsam are circulating in the region. Marcus Eriksen, a research director of the US-based Algalita Marine Research Foundation, which Mr Moore founded, said yesterday: "The original idea that people had was that it was an island of plastic garbage that you could almost walk on. It is not quite like that. It is almost like a plastic soup. It is endless for an area that is maybe twice the size as continental United States."
Curtis Ebbesmeyer, an oceanographer and leading authority on flotsam, has tracked the build-up of plastics in the seas for more than 15 years and compares the trash vortex to a living entity: "It moves around like a big animal without a leash." When that animal comes close to land, as it does at the Hawaiian archipelago, the results are dramatic. "The garbage patch barfs, and you get a beach covered with this confetti of plastic," he added.
The "soup" is actually two linked areas, either side of the islands of Hawaii, known as the Western and Eastern Pacific Garbage Patches. About one-fifth of the junk – which includes everything from footballs and kayaks to Lego blocks and carrier bags – is thrown off ships or oil platforms. The rest comes from land.
Mr Moore, a former sailor, came across the sea of waste by chance in 1997, while taking a short cut home from a Los Angeles to Hawaii yacht race. He had steered his craft into the "North Pacific gyre" – a vortex where the ocean circulates slowly because of little wind and extreme high pressure systems. Usually sailors avoid it.
He was astonished to find himself surrounded by rubbish, day after day, thousands of miles from land. "Every time I came on deck, there was trash floating by," he said in an interview. "How could we have fouled such a huge area? How could this go on for a week?"
Mr Moore, the heir to a family fortune from the oil industry, subsequently sold his business interests and became an environmental activist. He warned yesterday that unless consumers cut back on their use of disposable plastics, the plastic stew would double in size over the next decade.
Professor David Karl, an oceanographer at the University of Hawaii, said more research was needed to establish the size and nature of the plastic soup but that there was "no reason to doubt" Algalita's findings.
"After all, the plastic trash is going somewhere and it is about time we get a full accounting of the distribution of plastic in the marine ecosystem and especially its fate and impact on marine ecosystems."
Professor Karl is co-ordinating an expedition with Algalita in search of the garbage patch later this year and believes the expanse of junk actually represents a new habitat. Historically, rubbish that ends up in oceanic gyres has biodegraded. But modern plastics are so durable that objects half-a-century old have been found in the north Pacific dump. "Every little piece of plastic manufactured in the past 50 years that made it into the ocean is still out there somewhere," said Tony Andrady, a chemist with the US-based Research Triangle Institute.
Mr Moore said that because the sea of rubbish is translucent and lies just below the water's surface, it is not detectable in satellite photographs. "You only see it from the bows of ships," he said.
According to the UN Environment Programme, plastic debris causes the deaths of more than a million seabirds every year, as well as more than 100,000 marine mammals. Syringes, cigarette lighters and toothbrushes have been found inside the stomachs of dead seabirds, which mistake them for food.
Plastic is believed to constitute 90 per cent of all rubbish floating in the oceans. The UN Environment Programme estimated in 2006 that every square mile of ocean contains 46,000 pieces of floating plastic,
Dr Eriksen said the slowly rotating mass of rubbish-laden water poses a risk to human health, too. Hundreds of millions of tiny plastic pellets, or nurdles – the raw materials for the plastic industry – are lost or spilled every year, working their way into the sea. These pollutants act as chemical sponges attracting man-made chemicals such as hydrocarbons and the pesticide DDT. They then enter the food chain. "What goes into the ocean goes into these animals and onto your dinner plate. It's that simple," said Dr Eriksen.

Le vacche tedesche inquinano come i Suv



http://www.corriere.it/esteri/08_agosto_28/vacche_tedesche_inquinanti_aae9817a-750c-11dd-b47d-00144f02aabc.shtml

Thilo Bode, numero uno dell'organizzazione Foodwatch: «Sono una bomba climatica»

Non la scampa più nessuno, questa battaglia sui cambiamenti del clima. Ora, è il momento delle vacche tedesche: inquinano quanto i Suv e «sono una bomba climatica», sostiene Thilo Bode, numero uno di Foodwatch, organizzazione di difesa dei consumatori della Germania. Solo che – aggiunge – la lobby agricola è finora riuscita a tener il fatto nascosto, al contrario di quanto non hanno saputo fare acciaierie, produttori di energia, industria dell’automobile, compagnie aeree.
LO STUDIO - Foodwatch, dunque, ha effettuato uno studio, insieme all’Istituto per la ricerca sull’economia ecologica (Ioew), e i numeri che ne sono usciti sono assolutamente interessanti. L’agricoltura tedesca (ma ovviamente il discorso in varie misure vale per tutti i Paesi) manda nell’atmosfera ogni anno l’equivalente di 133 milioni di tonnellate di anidride carbonica, poco meno di quella emessa da tutto il traffico sulle strade della Germania (152 milioni di tonnellate). Mentre alle automobili stanno per essere applicate norme europee piuttosto severe per ridurre le emissioni, l’agricoltura è però praticamente assente dai programmi di abbattimento dei livelli di gas serra del governo tedesco e della Ue. Invece, dice Foddwatch, la questione non va sottovalutata e, anzi, dovrebbe spingere tutti a consumare meno carne, “a tornare al rito dell’arrosto domenicale”, ha detto Bode al settimanale Spiegel.

I NUMERI - Produrre un chilo di carne bovina con metodologie intensive (le più usate) equivale, in termini di emissioni, a un viaggio di 70,6 chilometri in utilitaria. Ancora peggio se il chilo di carne è prodotto con metodologia biologica: l’equivalenza è di 113,4 chilometri. Un chilo di formaggio emette quanto un’auto che viaggia per 71,4 chilometri. È necessario ridurre i consumi di carne, dicono dunque gli scienziati. Il calcolo delle missioni agricole e zootecniche tiene conto di una varietà di fattori: l’uso di fertilizzanti, di diserbanti, di pesticidi e il costante uso agricolo di zone umide, che provoca il rilascio nell’atmosfera di grandi quantità di anidride carbonica. Ma considera anche le emissioni corporee di ogni singolo animale: i ruminanti, per dire, emettono costantemente metano, un gas serra 23 volte più potente dell’anidride carbonica. Il ministero dell’Agricoltura tedesco, finora, ha evitato di affrontare il problema. Ma il ministero dell’Ambiente di Berlino ha preparato un documento (riservato) nel quale si sostiene che non ha senso lottare contro i cambiamenti climatici se poi si danno, attraverso la Politica agricola comunitaria, miliardi di euro a un settore che finora non si è nemmeno posto il problema dell’effetto serra. Ovviamente, c’è già chi propone di mettere una tassa “ecologica” sulla carne e sul latte.


domenica 24 agosto 2008

Gut Reactions /1


The termite’s stomach, of all things, has become the focus of large-scale scientific investigations. Could the same properties that make the termite such a costly pest help us solve global warming?
by Lisa Margonelli

Lisa Margonelli is an Irvine Fellow at the New America Foundation and the author of Oil on the Brain: Petroleum’s Long, Strange Trip to Your Tank (2007).

MOLECULAR WRECKING YARD: Electron-micrograph images of the termite's third gut, where food is turned into fuel(Images by Falk Warnecke, Phil Hugenholtz, Doe Joint Genome Institute and Manfred Auer, UC Berkeley and Lawrence Berkeley National Laboratory)

For more than a hundred million years, termites have lived in obscurity, noticed only by the occasional hungry anteater or, more recently, by dismayed home­owners. Other social insects, such as bees and ants, are celebrated for their industriousness and engineering feats, but popular culture has not gotten around to cheering on termites for theirs—even though they build mounds as tall as 20 feet, which may be oriented north-south as accurately as if plotted with a compass, in order to maximize heat from the sun. The extraordinary powers evolution has bestowed on termites—some protect the mound by spraying chemicals from nozzles on their heads at intruders, while others have snapping mandibles that can decapitate invading ants—have similarly failed to elevate their status. On the contrary: last year, scientists at the London Natural History Museum called termites “social cockroaches” and proposed reclassifying them, in a paper brusquely titled “Death of an Order.”
The more closely one examines the termite, the more mysteries one finds. In some species, if a termite discovers a contamination in the mound, it alerts everyone else, and a hygiene frenzy begins. As a disease passes through a mound, the survivors vaccinate the young with their antennae. When a mound’s queen is no longer capable of reproduction, the workers may gather around her distended body and lick her to death.
The greatest mystery of all is found in the worker termite’s third gut, which is delineated by an intricately structured stomach valve, as unique from species to species as individual snowflakes are and, in its way, just as lovely. The size of a sesame seed, the third gut contains a dense mush of symbiotic microbes. Many of these microbes live nowhere else on Earth; they depend on adult termites to pass them on to the young by means of a “woodshake,” a microbial slurry.
This microbial mush may be a treasure trove for the human race. Recently, sophisticated genetic sequencing produced an inventory of more than 80,000 genes, spanning some 300 microbial species, from the guts of Costa Rican termites. These findings, published last November in the journal Nature, got a lot of attention, not for the quantity of microorganisms—after all, the human mouth contains 600 species of bacteria—but for their complexity, and in particular for the fact that among them are 500 genes for enzymes able to break down the cellulose in wood and grasses.
With oil prices at historic highs, the quest is on to turn such plant materials into a replacement for gasoline—call it grass­o­line. Since 2007, U.S. energy policy has been shaped by the premise that we can brew enough biofuels to replace 35 billion gallons of gasoline by 2017, and 60 billion by 2030. Corn ethanol has been a bust, blamed for wasting water, exhausting croplands, and causing tortilla shortages in Mexico and rice shortages in Asia. For all these problems, it currently contributes the equivalent of only about 4.2 billion gallons of gas a year. And the carbon dioxide emitted in the process of growing and fermenting corn and then distilling and burning ethanol is nearly as much as that emitted by extracting, refining, and burning gasoline.
Wood and grasses seem to hold more promise. They contain chains of thousands of glucose molecules that could be made into so-called cellulosic ethanol and then burned like gasoline, while releasing just 15 percent of gasoline’s greenhouse-gas emissions. But there’s a catch. Wood has evolved to keep its sugars to itself, covering them with lignin—a substance that gives cell walls rigidity—and then locking them in a matrix of cellulose and hemicellulose protected by complex chemical bonds. Because these sugars are so hard to get at, our output of cellulosic ethanol is still, after decades of research, just 1.5 million gallons a year—less than 1 percent of one day’s gasoline consumption.
But where humans have failed, the termite succeeds—spectacularly. A worker termite tears off a piece of wood with its mandibles and lets its guts work on it like a molecular wrecking yard, stripping away sugars, CO2, hydrogen, and methane with 90 percent efficiency. The little biorefineries inside each termite allow the insects to eat up $11 billion in U.S. property every year. But some scientists and policy makers believe they may also make the termite a sort of biotech Rumpelstiltskin, able to spin straw—or grass, or wood by-products—into something much more valuable. Offer a termite this page, and its microbial helpers will break it down into two liters of hydrogen, enough to drive more than six miles in a fuel-cell car. If we could turn wood waste into fuel with even a fraction of the termite’s efficiency, we could run our economy on sawdust, lawn clippings, and old magazines.
And so the termite may be poised for its moment in the sun. Speaking last year about moving toward a biofuel economy, Energy Secretary Samuel W. Bodman pointed to the termite-to-tank concept, asserting, “We know this can be done.” Another official called it a promising “transformational discovery.” Suddenly the termite is everywhere, from Popular Science to Congressional Quarterly Today to Wired. With the audience for energy speeches and articles so small and wonky, it’s too soon to say that the little bug has exactly become a celebrity (although it did recently rate a footnote in Vanity Fair). But in some circles, it has attained a certain status as the pest that could solve our energy problems, transforming geopolitics and agriculture in the process. “Deus ex termita,” you might say.

Gut Reactions /2

http://www.theatlantic.com/doc/200809/termites

Perhaps—but it won’t be easy. Last year, in an initiative that has been compared to the Manhattan Project, the Department of Energy founded three Bioenergy Research Centers, which collectively house scientists from seven government labs, 18 universities, and several private companies, and are aimed at making cellulosic ethanol competitive with gasoline within five years. The effort, which has $375million in funding, is focused on plumbing the structures of woods and grasses and learning how various creatures break them down; genetic modifications, scientists hope, could then enable us to make cheaper fuels. The centers are expected to come up with ideas that can be commercialized—actually making them more like Bell Labs, say, than like the Manhattan Project.
Started two years earlier, the termite proj­ect described in Nature is based on the same model of public and private collaboration, and is now an important part of the bioenergy initiative. Indeed, termites might be seen as an “indicator species” for the larger effort—and, as scientists are learning, they are full of devilish details and vexing complications.
In 2005, the microbial ecologist Falk Warnecke, of the Department of Energy’s Joint Genome Institute, traveled with researchers from Caltech and the San Diego biotech company Diversa to Costa Rica, where they opened up a termite nest in a tree. The group dissected 165 worker termites, freezing the contents of their third guts in liquid nitrogen and shipping them to Diversa’s lab. After extracting the DNA from the microbial cells, Diversa sent a sample to the institute to be sequenced.
Housed in a low brick building in Walnut Creek, California, the Joint Genome Institute is sequencing the genes of hundreds of plants and microbes that might be useful for energy production and environmental cleanup; it is a key part of the Bioenergy Research Centers. Originally formed as part of the Human Genome Project in the late 1990s, the institute has its roots in the Department of Energy’s decades-long interest in tracking genetic mutations in atomic-bomb survivors and nuclear workers. The scale of its current mission becomes evident as soon as you enter the lobby, where a TV screen displays a ticker that tallies sequences by the minute, day, month, and year. When I arrived at about 10 o’clock one morning last spring, the day’s total stood at 25,555,288 DNA base pairs, the twinned nucleotides that are the building blocks of genes. Every second, another thousand base pairs joined the tally. Employees call this incessant data stream the “fire hose.” The institute now sequences as much DNA in an hour as it did in all of 1998, and the pace is planned to double by the end of the year.
Even for people accustomed to avalanches of data, the effort to map the contents of the termite’s third gut is extraordinary. “A disgusting mess of a data set,” says Phil Hugenholtz, the head of the institute’s Microbial Ecology Program. An angular Australian in his 40s, he speaks in rapid bursts, like a human fire hose. Traditional genomic analysis sequences one organism at a time, but Hugenholtz is a leading practitioner of metagenomics—the new science of sequencing genes from whole environments of microbes at once, and sorting out the resulting jumble of loose DNA code with the aid of computer science, statistics, and biochemistry. Metagenomics is not only breathtakingly fast; it allows us to catalog genes that were previously unknowable because so few types of microorganisms—fewer than 1 percent of all species of bacteria—can be cultured in a lab. Many biologists regard metagenomics as a scientific revolution akin to the invention of the microscope. In practice, though, it’s a sloppy art.
When the sequencers finished, they had 71 million letters of DNA code in tiny fragments. They sorted the fragments, assembled them into longer chains of genes, and scanned the genes to determine their likely functions and which of the 300 microbes they might have come from. Scientists then looked for combinations of chemicals that might be enzymes, comparing the results to enzymes known to work on cellulose. The metagenomic picture of the termite’s third gut that has so far emerged is a portrait of codes and probabilities—more sophisticated than a photograph from an electron microscope, but less satisfying, because so much remains indefinite.
Next, the scientists set about the long process of figuring out how all the parts work. “It’s like trying to learn about a house when someone’s given you nothing but the blueprints—and they’re all ripped up,” Hugenholtz says. Still, the blueprints were stunning. The termite gut contained much more than enzymes involved in breaking down wood into sugars: for example, there were a hundred species of spirochetes closely related to syphilis but here devoted to, among other things, producing hydrogen. There were also 482 appearances of a mysterious giant protein that Warnecke says looks like the international space station. He drew me a picture of a long, Lego-like scaffold with different enzymes plugged into it, hypothesizing that the protein might help strip sugars out of wood. But that was only a guess: “One of the disadvantages of finding so much is that you don’t know what it all means,” he told me.
Hugenholtz and Warnecke began sifting through the questions raised by the metagenome. Why do termites have 300 microbes and 500 different genes to degrade cellulose? How do you go about deciding which microbe is the most important? Do some termite species have stronger guts than others? And what on Earth was the space station doing? To tackle these questions, they needed more termites. They took some from cow patties on a Texas farm, surprising the elderly landowners by asking for a signed waiver on whatever intellectual property might develop.
One afternoon I watched Warnecke dissect 50 of the new termites. He worked at a rapid clip, pulling the insects’ heads and anuses in opposite directions with a microscopically violent yank; each termite’s gut unwound into a short, lumpy string. He showed me an electron-micrograph image of the inside of the gut. It looked like an undulating carpet. On it were rod-shaped bacteria; Warnecke pointed out pimple-like structures on the sides of a few, which he thought might be the space-station-like giant proteins. He speculated that the proteins work something like a Swiss Army knife, holding an array of tool-like enzymes and catalysts outside the cell to grab pieces of wood and whittle away, allowing the cell to slurp up the sugars thus released. If this hypothesis is correct, the proteins could be a great fit for biofuel production, because those loose sugars could be fermented into ethanol.
But the magnified images were far from conclusive. Hugenholtz slumped in front of the screen and complained that he saw no wood in the gut—were the termites starving? He impatiently made a list of tests he wanted done. Hugenholtz is confident that the team will eventually figure out what the proteins do. “You really see the science flailing around blindly here—but then things crystallize out of the darkness,” he told me.
One morning when I met Hugenholtz and Warnecke at a coffee shop, they began to riff on how the gut might work. “You get the feeling the microorganisms are more dominant than the termite. They must have a way to control the insect,” Warnecke said. Hugenholtz interrupted, quoting a colleague: “Maybe the termite is just a fancy delivery system for the creatures in the gut.” We tend to assume that the larger organism in a symbiotic relationship is in charge, but relationships like the one between the termite and the microbes involve constant two-way chemical communications. Even human beings, Hugenholtz said, are subconsciously eavesdropping on chemical conversations between the inhabitants of our guts; this leads us to crave, say, potato chips when our microbes want salt. His eyes fell warily on his coffee. “Do you think our stomach bacteria have trained us?”
History suggests that science follows its own timetable, often producing results long after the politicians who approved the funding have left office. Yet curiosity without the prospect of imminent practical application is something biotech investors are increasingly loath to pay for. When the Nature study began, Diversa was on the cutting edge of “ethical bioprospecting”—searching the world for novel environments and enzymes. After merging with a biofuels company, it became Verenium last year, and shifted to the more prosaic task of making commercial enzymes involved in the development of products including animal feed, paper, and fuels.
David Weiner, the assistant director of enzyme technology at Verenium, gave me a tour of the labs, showing me what he calls the “giant funnel”—the process the company uses to sift through nature’s intellectual property for enzymes that can be converted to profits. “We’re not really interested in DNA,” he said, meaning that the focus is on an enzyme’s performance, not its origins.
Whereas the Joint Genome Institute began by sequencing the termite-gut DNA—learning about its underlying structure—and only then tried to identify what might be useful, Weiner’s colleagues threw all the material from the Costa Rican expedition directly into testing, using the funnel approach to separate the most-useful enzymes from the millions of useless ones. Researchers inserted gene fragments into lab bacteria that had been genetically “tamed” to produce whatever enzyme the fragments were programmed to make. They then tested those enzymes on cellulose, to see if they would attack it. Only the winners made it to sequencing. You might think of the Joint Genome Institute as a group of diligent librarians, studying every step along the way. In contrast, a Verenium senior researcher told me, the company takes a “Julia Child approach”—once it has thrown together the ingredients (like termite guts and cellulose), it turns its attention to the final product, with far less focus on the stages in between.
Much of the action takes place in a machine—a type of robot, really—called the GigaMatrix. Clad in steel, the Giga­Matrix looks like a copier from the late 1980s, with two flat TV monitors on top and a door on the side. It can screen up to a million enzymes at a go, easily exceeding in a single day the lifetime performance of a human lab tech. The Giga­Matrix and other machines took the 500 or so most interesting enzymes from the termite gut and narrowed them down to fewer than 100 with potentially practical applications. Those were then tested for their effects on cellulose, modified, and inserted into “factory” bacteria trained to produce large quantities of enzymes while dining on cheap food, such as corn syrup. As the enzymes made their way through the process, every parameter of their growth and efficacy was measured. Only a small percentage proved powerful enough to merit continued investigation; these were stirred into multiple-enzyme “cocktails” to evaluate their speed and efficiency in combination. By the end, Weiner said, just a few enzymes remained in the running for further testing.
Geoff Hazlewood, a former senior vice president and now a consultant to Verenium, told me that the company has currently put aside studying termites for biofuels and has moved on to other potentially lucrative efforts. “You could screen ad nauseam,” he said, “but you can’t commit an infinite amount of resources.” Whatever the termites are doing may be too complicated and fragile to be useful in a large industrial process. There may be genius in the termite gut—Weiner calls it, admiringly, “a whole town”—but the wonders of symbiosis, in themselves, mean little to companies focused on the bottom line. “We want faster, cheaper, more efficient,” Weiner told me.

Gut Reactions /3

And it’s too early to tell whether the termite will ever provide genes or information that will enable biofuel production. Termite research could instead provide a cautionary tale about the difficulties of replicating nature on a political schedule. It may be faster and easier to come up with a comprehensive energy policy—investing in energy efficiency, changing personal behavior, and working with other large oil consumers to control prices—than to create a cellulose economy out of the termite gut. Termites certainly have their critics. One is Harvey Blanch, a professor of chemical engineering at UC Berkeley and the chief science and technology officer at the Department of Energy’s Joint Bio-Energy Institute, in Emeryville, California (where Hugenholtz also conducts research). “Those microbes eat pâté!” Blanch said. By the time wood reaches the termite’s third gut, he explained, it has been chewed to a fine consistency and soaked in the highly alkaline second stomach; the gut microbes don’t have to work very hard to break it down. Pretreating wood in similar ways on an industrial scale would be ridiculously expensive, he believes. He thinks the termite has been overhyped, and sees this as a reflection of unrealistically high hopes for quick, painless replacements for gasoline. Blanch has experienced the pitfalls of research driven by political goals. In the early 1970s, he worked on creating faux meat products from petroleum, which was then thought to be a cheap way to feed the world. For example, single-celled “chicken” proteins were produced by yeasts that fed on oil by-products, and then draped around plastic bones. But when the 1973 oil crisis hit, the cost of the raw material soared, effectively ending the petroprotein business. Blanch then shifted to cellulosic ethanol; the project was progressing until President Reagan killed it, in the mid-1980s. Now, he’s at once hopeful that we will one day be able to engineer novel organisms and make better fuels, and wary of putting too much faith in quick technological solutions. “Given the scale at which we need to operate, it’s hard to imagine any magic organism that will do the trick,” he told me. Several years ago, government labs set a goal of producing cellulosic ethanol for $1.33 a gallon by 2012, but Blanch cautions that the retail price could be $6 or $8 a gallon if the cost of the raw materials rises, and he thinks a realistic deadline is at least 10 years away. Perhaps because of his earlier experiences, he fears that projects that fail to deliver quickly are at risk, which puts a lot of pressure on both the Bioenergy Research Centers and individual researchers.
These concerns speak to an important tension underlying the termite research: the often competing agendas of work aimed at producing quick results, and of the slower, more methodical approach known as basic science, which tries to discover the fundamental logic of natural processes. Again, Julia Child (or maybe the more commercial Wolfgang Puck) versus the librarians. Some of the scientists—and even venture capitalists—I spoke with voiced fears that the race to harness nature for fuel production may cause us to neglect basic science and thus jeopardize potential long-term gains. Consider this: half of the 80,000 genes inventoried from the Costa Rican termites remain unidentified, and each of those 40,000, Warnecke imagines, could require a Ph.D. thesis to figure out. Hugenholtz says that metagenomics is grappling with the problem of having too much information and too few references. “Sequencing is far outstripping our ability to characterize the genes,” he explains, adding that this can lead to “genome rot”—a chain of errors created when one scientist gets a gene wrong, and then the mistake is multiplied across other genomes. The popular model of science is based on “eureka” moments, but right now, metagenomics is more like a big 3-D puzzle, where every new piece of knowledge—and every mistake—affects the whole. Trying to solve just one part of the puzzle for a quick commercial breakthrough may be as tricky as solving the entire thing. It could also cause us to give short shrift to alternative solutions. Eric Mathur was one of the Diversa executives who helped set up the Costa Rican expedition; he now works for Synthetic Genomics, a company founded by the scientific impresario Craig Venter to search for biology-based fuels and methods to cut greenhouse-gas emissions. Mathur says the Nature paper is just the beginning of a long process of understanding how symbiotic creatures deal with wood and carbon. He thinks that searching for individual enzymes in the termite will be a dead end, but that harnessing the power of whole environments might yield results. The challenge, he says, is to learn how these environments’ overall metabolisms work, and then use the tools of synthetic biology to engineer the organisms in them to evolve—creating a “slave organism” that focuses all of its resources, down to its last electron, on processing carbon. “Metabolic engineering is a very powerful method for productivity,” he told me. But the strongest argument for more basic research may be the termite itself. Jared Leadbetter, an associate professor of environmental microbiology at Caltech, remembers feeling “like an ecotourist in Alice in Wonderland” the first time he looked at a magnified termite gut, 18 years ago. Leadbetter has pioneered the study of the metabolism of a few of the spiro­chetes in the gut. Like Mathur, he believes scientists might put the termite’s gut to work against global warming by using it to understand and possibly alter the carbon cycle—the biogeochemical give-and-take of greenhouse gases between the Earth and its atmosphere. Leadbetter says one of the extraordinary things about termites is not how much ethanol they might make, but how little methane they produce. Cows lose 20 percent of the energy in the grass they eat, because the microbes in their stomachs combine hydrogen and carbon dioxide from the grass to make methane, a greenhouse gas that traps 20 times as much heat in the atmosphere as CO2. In 2006, the greenhouse gases produced by U.S. farm animals exceeded the emissions of the iron, steel, and cement industries combined. Termites lose less than 2 percent of their nutrients to methane production, because the spirochetes in their guts transform hydrogen and carbon dioxide into acetate, which the termites use as fuel. If we understood this process, perhaps we could put new microorganisms into the stomachs of cows and reduce their production of methane. We’re a long way from changing the chemistry of cows’ stomachs, but the process of adapting and commercializing the termite’s role in the carbon cycle has already yielded success on a small scale. The Virginia-based company ArcTech trained termites to eat coal, and then rummaged through their guts to find the microorganisms best at turning coal into methane. It cultured those microorganisms and now feeds them coal; the company plans to use the methane they produce to make electricity, and is already selling the by-products, including one used by farmers as a soil additive. ArcTech says this method eliminates virtually all greenhouse-gas emissions from coal-based electricity production. Other companies are trying to engineer similar organisms that could be sent into abandoned mines and oil wells to scavenge fuel that goes unused because it is so hard to get at. Such efforts could have a dramatic effect on both the environment and geopolitics: experts estimate that increasing the yield of oil wells from the current average of 35 percent of the oil in a reservoir to 40 percent would be the equivalent of discovering a new Saudi Arabia. Who knows what other answers may lurk in the termite? Elizabeth Ottesen, a graduate student doing research in Leadbetter’s lab, dissected a termite and put it under a microscope to give me a tour of its gut. At first glance, the dark mass of the gut was immobile, the organisms apparently packed too tightly to move, but as Ottesen added water, a menagerie of blobby Trichonympha, whizzing spirochetes, and other creatures materialized, all supported by gangs of bacteria too small to see. The inhabitants here are arranged in hierarchies more elaborate than Manhattan real estate, she said: Those at the edges use oxygen, while those in the middle are anaerobes. Many are high-speed commuters, outfitted with complicated sensing and swimming apparatus that helps them find hydrogen and other gases. Among the creatures in the termite’s gut, and especially among those creatures’ genes, exist redundancies that suggest the system has been over­engineered to survive the worst (including being force-fed coal). A spirochete’s flagella, for example, are between the layers of a double skin, enabling the organism to drill through the most viscous environments. Leadbetter expects it will take at least 25 years to unravel what he calls the “teleological questions” about the termite’s complexity. Along the way, the termite will likely provide clues to solving climate change, but Leadbetter thinks its greatest value may be as a repository of biological wisdom gathered over the course of more than 100 million years of survival on Earth. “When you look at a termite and its gut,” he says, “you’re looking at a long line of winners.”

giovedì 21 agosto 2008

testi antichi salvati dal metodo antispam




Avete presente quei test in cui, per accedere alla risorsa contenuta in una pagina web o per intervenire in un blog, si deve scrivere una sequenza di parole o numeri che appaiono sfocati e sembrano buttati lì sullo schermo? Sono i Captcha, test inventati per contrastare le sofisticate tecniche degli spammer. Ebbene, quando riportate le parole di questi Captcha, potrebbe darsi che stiate dando un contributo alla digitalizzazione di testi antichi. E quindi alla loro salvezza. Da un anno, infatti, le cronache, le riflessioni, le poesie e i racconti conservati nelle biblioteche hanno milioni di nuovi alleati, che lavorano senza saperlo. Finora, grazie ad un'idea semplice ma innovativa, sono state tradotte in formato digitale 440 milioni di parole, l'equivalente di 17.600 volumi. I progetti di digitalizzazione dei libri sono moltissimi, perché trasformare l'inchiostro in bit consente di preservare i loro contenuti e di renderli disponibili on line. Di solito si passano le pagine allo scanner e si sottopongono le immagini ad un software di riconoscimento ottico dei caratteri (OCR), che trasforma i testi in un formato riconoscibile dai computer. Il problema è che spesso la carta è ingiallita e le lettere sono poco leggibili, quindi il programma ha bisogno dell'aiuto di un essere umano. E l'intervento di un operatore, ovviamente, costa e rallenta enormemente il procedimento. Un gruppo di ricercatori della Carnegie Mellon University ha avuto un'intuizione. Ogni giorno, attraverso i Captcha, decine di milioni di persone decifrano su internet delle parole distorte per dimostrare di non essere dei software automatici che cercano di diffondere spam. Perché non sfruttare questa enorme forza lavoro gratuita per dare una mano ai software OCR?

È stato dunque messo a punto reCaptcha, una versione "intelligente" del sistema antispam. Quando una parola è interpretata in modo diverso da due software OCR è identificata come "sospetta". A quel punto viene unita ad una di quelle conosciute dal sistema. L'accoppiata è sottoposta agli utenti e, se un umano interpreta correttamente la parola di controllo, si presume che anche l'altra sia stata decifrata. Quando la stessa soluzione viene fornita da tre persone è considerata corretta e la parola è archiviata. La sperimentazione è stata avviata da circa un anno, con l'apertura di un sito dal quale chiunque può scaricare gratuitamente reCaptcha per inserirlo nelle proprie pagine web. Il successo dell'iniziativa è stato sorprendente. Nei primi dodici mesi i visitatori di circa 40mila siti web hanno decifrato 440 milioni di parole con un'accuratezza del 99%. "Attualmente vengono tradotte 4 milioni di parole al giorno - dice Luis Von Ahn, uno dei ricercatori coinvolti nel progetto - Per ottenere i risultati che raggiungiamo in una settimana, più di 1.500 persone dovrebbero lavorare per 40 ore a testa ad un ritmo di 60 parole al minuto". ReCaptcha collabora con l'Internet Archive, un'organizzazione non profit che digitalizza i libri di 70 biblioteche e università statunitensi, e con il New York Times, che intende così salvaguardare il suo archivio. Secondo i suoi creatori, che hanno presentato il progetto sull'ultimo numero di Science, questo è solo l'inizio. Attualmente viene tradotto l'equivalente di 160 libri al giorno, ma la diffusione del nuovo sistema potrebbe far lievitare queste cifre, salvando intere biblioteche. Anche lo spam, in un modo o nell'altro, alla fine può rivelarsi utile. (19 agosto 2008)

domenica 17 agosto 2008

I comunisti mangiano i conigli. Giant Rabbits Hit the Big Screen


http://www.spiegel.de/international/zeitgeist/0,1518,535596,00.html

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A German breeder of huge hares has hit the big time. A short film about a plan to send monster bunnies to North Korea for food was part of the Berlin Film Festival. It seems that Communist functionaries ate the rabbits before they could benefit the poor.

A German pensioner who
made headlines last year (more...) for breeding giant rabbits -- and selling a batch to North Korea with the idea of easing hunger -- is the subject of a short documentary by an American director in the the 2008 Berlin Film Festival. Director Julius Onah made the five-minute film -- a clip can be seen by clicking on the video below -- after reading about Karl Szmolinsky on SPIEGEL ONLINE. And in doing so, he learned that the rabbits may have been eaten by North Korean functionaries instead of the starving people for whom they were intended.
Szmolinsky is a 68-year-old German living in Eberswalde, near Berlin, who won a prize for breeding a 10.5-kilogram (23.1 pound) rabbit named Robert in 2006. Robert was the size of a small dog. When North Korean leaders saw photos of him they contacted Szmolinsky through a breeding federation, hoping to purchase a line of "German Giant Grays" to alleviate hunger in their hermetic Communist state.
Szmolinsky grew up in East Germany, and he agreed to help. He sold a dozen to the North Koreans at a cut rate -- 80 euros instead of the going rate of 200 or 250 euros -- and told SPIEGEL ONLINE in early 2007 that the 12 rabbits could produce 60 babies a year. Each animal, he estimated, would feed about eight people. "They'll be used to help feed the population," he said at the time. "I've sent them 12 rabbits so far; they're in a petting zoo for now. I'll be travelling to North Korea in April to advise them on how to set up a breeding farm. A delegation was here and I've already given them a book of tips."
After reading about Szmolinsky during a visit to Germany in January 2007, Onah assembled a film crew. He visited Szmolinsky in the wake of worldwide publicity about his anti-hunger scheme, on a day when the rabbit breeder was fielding phone calls from complete strangers who objected to his deal with the North Koreans.
"We actually didn't spend that much time talking about the rabbits," said Onah. "We spent most of our time talking about conditions in East Germany, both before and after the fall of the Wall." But concerned strangers had started complaining to Szmolinsky for sending live animals to North Korea, where animal-rights standards aren't up to snuff.
The resulting short, called "Szmolinsky," concentrates on the harassing phone calls.
Onah, 25, is a graduate student at New York University's film school and he made "Szmolinsky" to fulfill a class assignment. The film is evocative but not detailed; Onah spent a total of four hours with Szmolinsky and only later learned what became of his project to feed North Korea.
"In April of '07 Szmolinsky was supposed to go to North Korea himself and oversee the breeding of the rabbits," Onah told SPIEGEL ONLINE. "But some time between January and April he found out that the rabbits he sent got eaten (by senior officials). All 12 of them. So he refused to cooperate (more...) with the North Koreans."
Meanwhile the South Korean government has contacted Szmolinsky. "The South Koreans would like him to send his rabbits there," said Onah, "and they sent this letter which even apologized for the behavior of their neighbors in the north."
Szmolinsky himself attended the Berlinale premiere of the film with one of his giant rabbits on February 8. Onah said he might make a longer film about the story, given funding and time -- he's interested in the parallels between a divided Cold-War Germany and a divided Korean peninsula -- but right now other projects are crowding his schedule.

Big German Bunnies May Help Feed N. Korea


January 16, 2007 · A faded sign on the front door says beware of the dog, but the rabbits caged in Karl Smolinsky's backyard in Eberswalde, Germany, could be a little frightening, too — if you aren't expecting 22-pound bunnies with ears eight inches long.
After Smolinsky's rabbit Robert won the title of biggest rabbit in Germany last year, the North Korean government came to take a look. Last month, for just over $100 a head, Smolinsky shipped four big bucks — including Robert — and eight huge hares to Pyongyang to start a government sponsored breeding program.
The Koreans weren't at all interested in the smaller breeds — only the big ones. The minister who was here didn't want any rabbits that were under 10 kilograms.
He says a rabbit that size can provide seven kilos — about 15 pounds — of meat.
"You can eat all the parts of a rabbit," Smolinsky says. "Everything but the intestines. Lungs, liver... from the stomach, you can make a roulade, a stuffed meat dish. There's lots of meat in the head. You can take it out and make liverwurst. Every part of the rabbit is good except the bones — those are for the dog!"
Smolinsky's rabbits munch a pellet mix that includes oats, apples and oil. They also eat greens, including fresh kale from his garden. Smolinsky says a giant rabbit needs to eat about two pounds of food a day. That's twice as much as the North Korean government distributes to many of its people to survive. But Smolinsky isn't worried the rabbits will starve. He's heard German potatoes grow there.
"I don't feed them raw potatoes, but cooked potatoes, steamed potatoes are OK," he says. "And rice, during communist times here, we didn't have so much available as now, so we also bought rice for them. But when you feed them rice they must also have a lot of liquids, so they don't get bloated or stopped up."
The North Korean embassy in Berlin told NPR there is enough food for the rabbits. Michael Dunford, deputy director in North Korea of the United Nations' food aid program says at this point there is just enough food for people.
"We haven't seen evidence of starvation," Dunford says. "We are concerned that the food insecurity is worsening, and given the amount of food that arrived in the country last year it will have an impact in what we call the lean season."
The lean season is this spring, when last year's harvest will start to run out. International contributions to feed North Korea dropped dramatically after Pyongyang tested a nuclear weapon last fall. Major supporters — the U.S., Japan and South Korea — suspended food aid entirely.
Smolinsky says he's not worried about helping a dictatorship. He's thinking about hungry children.
"During Hitler's time and afterward, I remember how hard it was on everyone," he says. "I lived it as a child and wouldn't wish that on my worst enemy. I hope through the rabbits I can help a little bit, and that Korea might wake up and start caring more for its people than for the bomb."
Even if international sales grow, Smolinsky is keeping his favorite rabbit, the 18-pound Robert the Second, son of the first. He's hoping this spring to go visit his dozen already breeding at an agricultural enterprise near Pyongyang.

La ecología, otra gran víctima de la crisis


http://www.elpais.com/articulo/opinion/ecologia/gran/victima/crisis/elpepiopi/20080722elpepiopi_12/Tes?print=1

La necesidad de dar respuesta política a los precios del petróleo y los alimentos amenaza las causas ecologistas. Muchos Gobiernos piensan en nucleares, transgénicos y otras soluciones poco o nada verdes
PAUL KENNEDY 22/07/2008


Hay muchos perdedores en nuestro nuevo mundo de gasolina y alimentos caros: los pobres en casi todas partes, las clases medias bajas, las compañías aéreas, las empresas de importación de alimentos... Y ahora aparece una nueva víctima: el sueño ecologista de conseguir un mundo más sostenible, equilibrado y equitativo. Esa visión de una Tierra armoniosa está amenazada por todas partes.
A algunos puede extrañarles esta conclusión. ¿Acaso los elevados precios del petróleo no recortan nuestras costumbres gastadoras? ¿No es positivo que entremos en un mundo sin Hummers? ¿No se nos está empujando a tomar medidas de ahorro energético? ¿No se nos está obligando a buscar fuentes de energía alternativas y más inteligentes: la energía solar y la térmica, la energía eólica y la de las olas?
Sí, todo eso es verdad. Pero, al mismo tiempo, también se está obligando a la población y las autoridades a adoptar políticas a las que el movimiento ecologista se ha opuesto, a menudo con éxito, desde hace 40 años. Desesperados por amortiguar el golpe que supone un petróleo a 130 dólares o más el barril y por prevenir el descontento popular, los Gobiernos están tomando medidas que dejan helados a casi todos los ecologistas.
La lista de retrocesos es larga. Mientras en el norte hay familias que vuelven a las estufas de leña, en los trópicos hay comunidades que talan bosques con más intensidad que nunca, y en India los más pobres queman estiércol y un queroseno de dudosa procedencia. Aún más, el Congreso de Estados Unidos recibe fuertes presiones para incrementar las perforaciones y extracciones en plataformas marinas delicadas desde el punto de vista ambiental, como el norte de Alaska y una franja del norte del Estado de Nueva York. Muchos Gobiernos quieren volver a la energía nuclear y preven construir decenas de nuevos reactores, que se unirán a numerosas nuevas plantas alimentadas por carbón.
Como es natural, los ecologistas se oponen, pero es dudoso que puedan oponerse en estos tiempos turbulentos a las presiones, los argumentos y las campañas en contra. Los argumentos sobre la seguridad nacional y la necesidad de reducir la dependencia de fuentes energéticas extranjeras e inseguras, las presiones para aumentar los subsidios a los combustibles en los países en vías de desarrollo y las campañas para reducir los impuestos sobre el petróleo y el gasóleo para los pescadores, los camioneros y las pequeñas empresas en los países industrializados.
Hasta hace poco, era posible alegar que una gran subida de los impuestos sobre el combustible podía ayudar a reducir nuestra afición a los todoterrenos devoradores de gasolina (además de incrementar las arcas del Gobierno). Hoy día, salvo entre las poblaciones más progresistas y acomodadas, sería imprudente el político que propusiera una cosa así.
Y luego está la decisión, muy controvertida, de incrementar la energía alternativa de moda, el etanol, sobre todo en su modalidad menos sensata, que es la de producir el combustible a partir de maíz. No sólo es mucho menos eficaz que el proceso a partir de caña de azúcar, y no sólo beneficia de forma desproporcionada a determinados intereses especiales agrarios y empresariales, sino que -al menos en el caso de Estados Unidos- ha tenido un efecto de sustitución negativo. Ahora que los agricultores del Medio Oeste de EE UU se han pasado al monocultivo y han convertido miles de hectáreas de soja y trigo en maíz, el precio de los primeros ha subido.
Esto nos lleva al derrumbe de la esperanza ecologista en que avancemos hacia una producción de alimentos más benigna con el medio ambiente (es decir, "orgánica"), con unos agricultores locales que cobran precios decentes (es decir, "comercio justo") a unos consumidores agradecidos y más sanos. No sólo la crisis energética está colocando a muchos agricultores y pescadores contra las cuerdas, sino que el aumento de los costes de los alimentos en general y la demanda creciente de 1.000 millones más de asiáticos están reavivando los llamamientos a tomar unas medidas que los ecologistas siempre han detestado.
Así que no tengo la menor duda de que los argumentos en favor de la producción de alimentos transgénicos tienen muchas más posibilidades de ser aceptados hoy que hace 10 años; si hay que escoger entre las necesidades dietarias de 6.500 millones de personas (en 2050, quizá 9.000 millones) y los temores sobre los alimentos transgénicos, el resultado parece claro.
La demanda de alimentos permitirá vencer las aprensiones sobre el método de producción. Lo mismo ocurrirá probablemente con los llamamientos de algunas empresas agroquímicas para que se utilicen más fertilizantes y pesticidas. Cada lado asegurará tener la ciencia de su parte y recurrirá a sus propios expertos. Pero, al final, es muy posible que las consideraciones políticas y de seguridad pesen más que las preocupaciones ecológicas y de salud.
Las inseguridades sobre el abastecimiento de alimentos ya han hecho que los grupos agrarios de presión de tipo proteccionista, desde Francia hasta Japón, afirmen que sus políticas de altos aranceles sobre las importaciones de alimentos han estado muy justificadas, porque sólo con el mantenimiento (o incluso el refuerzo) de esas barreras pueden los países tener garantizada la presencia en la mesa de pan y manzanas en momentos de crisis.
Estas afirmaciones interesadas preocupan a los economistas del desarrollo, que dicen que la mejor forma de que Europa ayudara a África a prosperar sería permitir la importación de alimentos y, de esa forma, mejorar el nivel de vida de millones de cultivadores africanos de frutas, aceite de oliva, cereales, vino y otros productos. Pero por sólido que sea este argumento, las posibilidades de que se haga realidad y de que se establezca un régimen de libre comercio agrario mundial han disminuido.
Y aún no hemos hablado de las posibilidades de agitación política y social como consecuencia del encarecimiento del combustible y los alimentos, algo de lo que el Banco Mundial y la Organización Mundial de Alimentos llevan tiempo advirtiendo.
Se podría escribir otra media docena de artículos sobre todos los aspectos del problema. Lo único que hemos hecho aquí es señalar que las nuevas tendencias, con sus repercusiones tanto en los países ricos como en los pobres (salvo unos cuantos exportadores de petróleo), están erosionando, y van a erosionar aún más, muchas de las victorias conseguidas y de las teorías sostenidas por el movimiento ecologista.
La intensificación de las perforaciones de petróleo en zonas delicadas, el regreso de la energía nuclear, las presiones sobre los bosques tropicales y boreales, la preferencia por el etanol procedente de maíz, la posibilidad creciente de que se recurra a la agricultura transgénica y a un mayor uso de fertilizantes y el impulso dado al proteccionismo agrario del Primer Mundo son elementos que suscitan pesimismo entre los amigos de la tierra. Y deberían suscitarlo entre nosotros también.
Por supuesto, los ecologistas resistirán y, a largo plazo, es incluso probable que los desorbitados precios energéticos sirvan de aliciente para crear fantásticas tecnologías alternativas. A los lectores que vivan en comunidades con alto nivel de educación y de conciencia ecológica (y de renta), desde Seattle hasta Estocolmo, y que ya disfruten de las nuevas tecnologías inteligentes, este artículo puede parecerles demasiado sombrío. Pero es posible que no se den cuenta de lo privilegiada que es su situación en comparación con la mayor parte de la humanidad. En estos momentos, los tremendos aumentos de los costes del combustible y los alimentos están haciendo que muchos reclamen una rebaja de las exigencias en muchos frentes. Si esa tendencia prevalece, es muy probable que nuestro mundo se aleje cada vez más del sueño ecologista sobre una humanidad capaz de ordenarse de otra manera.
Quizá ese sueño no podía hacerse realidad ante nuestra continua expansión demográfica, el increíble aumento de la demanda de bienes y servicios que la acompaña y el agotamiento de varias reservas clave de materias primas. Sea o no así, la desagradable realidad actual es que las cosas no están mejorando, sino todo lo contrario, para los defensores de un planeta más limpio y acogedor.
© 2008, Tribune Media Services, Inc.

Paul Kennedy es director del Instituto de Estudios sobre Seguridad Internacional de Yale.

venerdì 1 agosto 2008

Scientists mimic essence of plants' energy storage system


http://web.mit.edu/newsoffice/2008/oxygen-0731.html

In a revolutionary leap that could transform solar power from a marginal, boutique alternative into a mainstream energy source, MIT researchers have overcome a major barrier to large-scale solar power: storing energy for use when the sun doesn't shine.


Daniel Nocera describes new process for storing solar energy
View video post on MIT TechTV
Until now, solar power has been a daytime-only energy source, because storing extra solar energy for later use is prohibitively expensive and grossly inefficient. With today's announcement, MIT researchers have hit upon a simple, inexpensive, highly efficient process for storing solar energy.
Requiring nothing but abundant, non-toxic natural materials, this discovery could unlock the most potent, carbon-free energy source of all: the sun. "This is the nirvana of what we've been talking about for years," said
MIT's Daniel Nocera, the Henry Dreyfus Professor of Energy at MIT and senior author of a paper describing the work in the July 31 issue of Science. "Solar power has always been a limited, far-off solution. Now we can seriously think about solar power as unlimited and soon."
Inspired by the photosynthesis performed by plants, Nocera and Matthew Kanan, a postdoctoral fellow in
Nocera's lab, have developed an unprecedented process that will allow the sun's energy to be used to split water into hydrogen and oxygen gases. Later, the oxygen and hydrogen may be recombined inside a fuel cell, creating carbon-free electricity to power your house or your electric car, day or night.
The key component in Nocera and Kanan's new process is a new catalyst that produces oxygen gas from water; another catalyst produces valuable hydrogen gas. The new catalyst consists of cobalt metal, phosphate and an electrode, placed in water. When electricity -- whether from a photovoltaic cell, a wind turbine or any other source -- runs through the electrode, the cobalt and phosphate form a thin film on the electrode, and oxygen gas is produced.
Combined with another catalyst, such as platinum, that can produce hydrogen gas from water, the system can duplicate the water splitting reaction that occurs during photosynthesis.
The new catalyst works at room temperature, in neutral pH water, and it's easy to set up, Nocera said. "That's why I know this is going to work. It's so easy to implement," he said.
'Giant leap' for clean energy
Sunlight has the greatest potential of any power source to solve the world's energy problems, said Nocera. In one hour, enough sunlight strikes the Earth to provide the entire planet's energy needs for one year.
James Barber, a leader in the study of photosynthesis who was not involved in this research, called the discovery by Nocera and Kanan a "giant leap" toward generating clean, carbon-free energy on a massive scale.
"This is a major discovery with enormous implications for the future prosperity of humankind," said Barber, the Ernst Chain Professor of Biochemistry at Imperial College London. "The importance of their discovery cannot be overstated since it opens up the door for developing new technologies for energy production thus reducing our dependence for fossil fuels and addressing the global climate change problem."
'Just the beginning'
Currently available electrolyzers, which split water with electricity and are often used industrially, are not suited for artificial photosynthesis because they are very expensive and require a highly basic (non-benign) environment that has little to do with the conditions under which photosynthesis operates. More engineering work needs to be done to integrate the new scientific discovery into existing photovoltaic systems, but Nocera said he is confident that such systems will become a reality. "This is just the beginning," said Nocera, principal investigator for the Solar Revolution Project funded by the Chesonis Family Foundation and co-Director of the Eni-MIT Solar Frontiers Center. "The scientific community is really going to run with this."
Nocera hopes that within 10 years, homeowners will be able to power their homes in daylight through photovoltaic cells, while using excess solar energy to produce hydrogen and oxygen to power their own household fuel cell. Electricity-by-wire from a central source could be a thing of the past.
The project is part of the
MIT Energy Initiative, a program designed to help transform the global energy system to meet the needs of the future and to help build a bridge to that future by improving today's energy systems. MITEI Director Ernest Moniz, Cecil and Ida Green Professor of Physics and Engineering Systems, noted that "this discovery in the Nocera lab demonstrates that moving up the transformation of our energy supply system to one based on renewables will depend heavily on frontier basic science." The success of the Nocera lab shows the impact of a mixture of funding sources - governments, philanthropy, and industry. This project was funded by the National Science Foundation and by the Chesonis Family Foundation, which gave MIT $10 million this spring to launch the Solar Revolution Project, with a goal to make the large scale deployment of solar energy within 10 years.