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There is a type of rock with a voracious appetite for carbon dioxide

ONE way of helping to reduce emissions of carbon dioxide into the atmosphere is to pump the gas into underground caverns or old oil fields. But there is also a rock that is happy to gobble it up, and according to the latest research its appetite for the greenhouse gas is not only massive but could also be increased by a little human intervention.

The rock is peridotite, which is one of the main rocks in the upper mantle, an area that provides a girth below the Earth’s crust. The rock occurs some 20km or more down, although in areas where plate tectonics have forced up some of the mantle, peridotite reaches the surface. This happens in part of the Omani desert which Peter Kelemen and Juerg Matter, both from Columbia University, New York, have studied for years.

Geologists have long known that when peridotite is exposed to the air it can react quickly with carbon dioxide to form carbonates like limestone or marble. Some people have looked at the idea of grinding up peridotite and using it to soak up emissions from power stations, but the process turns out to be expensive, partly because of the costs of transporting all the rock. The transportation would also create emissions. InProceedings of the National Academy of Sciences, Messrs Kelemen and Matter suggest an alternative: pumping the gas from places where it is produced and into underground strata of peridotite.

The team has shown that the Omani peridotite absorbs tens of thousands of tonnes of carbon dioxide a year, far more than anyone had thought. By drilling and fracturing the rock they believe they can start a process to increase the absorption rate by 100,000 times or more. They estimate this would allow the Omani outcrop, which extends down some 5km, alone to absorb some 4 billion tonnes of carbon dioxide a year, which is a substantial part of the annual 30 billion or so tonnes of the gas that humans send into the atmosphere, mostly by burning fossil fuels.

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photo credit: mujitra (´･ω･)

The world’s carmakers have mapped out their route to a greener future

THERE is nothing like high oil prices, panic-selling of big cars and the prospect of swingeing new penalties on carbon-spewing vehicles to concentrate the minds of the world’s carmakers. In less than two years something remarkable has happened. Technologies once regarded by horsepower-obsessed marketing departments as politically correct public-relations fluff, never likely to see the light of day, are entering the mainstream just as fast as the car firms can get them there.

Only 18 months ago it was common to hear Toyota’s pioneering Prius hybrid joked about as a funny-looking niche vehicle with which Hollywood stars could painlessly flaunt their green credentials. Although General Motors (GM) had exhibited a plug-in hybrid concept car, called the Chevrolet Volt, early in 2007, hardly anyone took seriously the claim that it might reach production in 2010. And just ten months ago carmakers in America were lining up to lobby Congress against proposed legislation that would oblige them to achieve a fleet-average fuel consumption of 35 miles per gallon (mpg) by 2020. It simply could not be done, they wailed.

In Europe a similar campaign, with the German carmakers to the fore, was being waged against a plan by the European Commission to impose financial penalties by 2012 on companies if their fleets emitted, on average, over 130 grams of carbon dioxide per kilometre (g/km). It was, they said, technically impossible to comply with the new rules, which they saw as a wicked plot to emasculate a proud and successful industry.

The grumbling about tighter emissions laws will continue, but spurred on by rocketing prices at the pump and changing customer preferences, the manufacturers have quietly got on with the job of transforming the fuel and CO2 efficiencies of their vehicles. Moreover, the blue-sky thinking of the recent past which, encouraged by large government subsidies and conveniently elastic time horizons, appeared to favour the hydrogen fuel-cell, has been dumped for the practical and achievable. Although carmakers differ over the details of the coming revolution in efficiency, there is now a consensus across the industry about its thrust, and about both the role of the underlying technologies and when they will be on sale.

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In the world of alternative fuels, there may be nothing greener than pond scum.

Algae are tiny biological factories that use photosynthesis to transform carbon dioxide and sunlight into energy so efficiently that they can double their weight several times a day.

As part of the photosynthesis process algae produce oil and can generate 15 times more oil per acre than other plants used for biofuels, such as corn and switchgrass. Algae can grow in salt water, freshwater or even contaminated water, at sea or in ponds, and on land not suitable for food production.

On top of those advantages, algae — at least in theory — should grow even better when fed extra carbon dioxide (the main greenhouse gas) and organic material like sewage. If so, algae could produce biofuel while cleaning up other problems.

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photo credit: BrokenBat

Environmental Engineers Use Algae To Capture Carbon Dioxide

Engineers have designed a simple, sustainable and natural carbon sequestration solution using algae. A team at Ohio University created a photo bioreactor that uses photosynthesis to grow algae, passing carbon dioxide over large membranes, placed vertically to save space. The carbon dioxide produced by the algae is harvested by dissolving into the surrounding water. The algae can be harvested and made into biodiesel fuel and feed for animals. A reactor with 1.25 million square meters of algae screens could be up and running by 2010.

Global warming’s effects can be seen worldwide, and many experts believe it’s only going to get worse. In fact, America is by far the largest contributor to global warming than any other country — releasing a quarter of the world’s carbon dioxide — the primary cause of global warming. But now engineers have found a natural way to eliminate one of the worst contributors to our environment’s decay.

What’s coming from power plants, traffic jams and industrial smog is causing our ozone to disappear, ice caps to melt, and temperatures to rise. The latest international report says carbon dioxide responsible for 60 percent of the greenhouse gases.

Now engineers say a simple, sustainable and natural solution may come from algae. “If this sort of technology can be developed, it can be deployed anywhere there’s sunlight,” David Bayless, a professor of mechanical engineering at Ohio University in Athens, tells DBIS.

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photo credit: fingle

In search of forever

As a source of power for cars, fuel cells have been a disappointment. For laptops and mobile phones, they are just about to take off.

METHANOL is nasty stuff. Careless distillation in many a backwoods still has caused it to blind the imbibers of “alternative” alcoholic drinks. Yet it has its uses, and one of them may be to restore fuel cells to their oft-vaunted role as the power packs of the future—but with a twist. The main role that has been discussed for fuel cells over the past few decades is as replacements for the internal-combustion engine. Their actual use may turn out to be to provide power for portable electronic devices.

A fuel cell is a device that combines hydrogen with oxygen to generate electricity. The traditional approach has been to use the gas itself in the cell—and that is the approach taken by the world’s carmakers in their so-far not very successful attempts to make a commercial fuel-cell-driven car. Since gaseous hydrogen is hard to store and handle, an alternative that some people have considered is to lock the hydrogen up in methanol, a liquid whose molecules are made of a carbon atom, an oxygen atom and four hydrogen atoms. Methanol will react with water in the form of steam to make hydrogen and carbon dioxide—a process known as steam reformation. Put a steam reformer in a car along with the fuel cell and you can fill the tank with methanol instead of hydrogen.

That idea has not gone very far, either. But it has provoked another thought. What if it were possible to decompose the methanol without steam, and within the fuel cell itself? And that has, indeed, turned out to be possible. The resulting cells are nowhere near powerful enough to run cars, but they are plenty powerful enough to stand in for small batteries. What is more, they last far longer than batteries and when they do need recharging, it is the work of a moment.

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photo credit: teejaybee

The other day I went to a meeting to hear Harrison Ford talk about saving the rain forests and ended up listening to a man who has a rain forest to save: Guyana’s president, Bharrat Jagdeo.

The occasion was the announcement of a new campaign to protect the world’s rain forests, Guyana’s included, organized by the environmental group Conservation International. (Mr. Ford, a board member, was in New York to promote his new movie and somehow got his schedule wrong.)

That left the spotlight where it belonged: on Mr. Jagdeo and his mission to get the world’s rich nations to help save Guyana’s huge rain forest from chainsaws and prevent the release of billions of tons of carbon dioxide, the main global-warming gas.

Mr. Jagdeo caused a stir last year when he offered to cede the management of his country’s entire rain forest — 40-plus million acres, covering 80 percent of Guyana’s land mass — to a British government agency in return for British economic assistance. Though the British have yet to take him up on the deal, Mr. Jagdeo continues to press the case for protecting not only his rain forest, but all of them.

photo credit: Robert Whitlock

Cod caught off Norway is shipped to China to be turned into filets, then shipped back to Norway for sale. Argentine lemons fill supermarket shelves on the Citrus Coast of Spain, as local lemons rot on the ground. Half of Europe’s peas are grown and packaged in Kenya.

In the United States, FreshDirect proclaims kiwi season has expanded to “All year!” now that Italy has become the world’s leading supplier of New Zealand’s national fruit, taking over in the Southern Hemisphere’s winter.

Food has moved around the world since Europeans brought tea from China, but never at the speed or in the amounts it has over the last few years. Consumers in not only the richest nations but, increasingly, the developing world expect food whenever they crave it, with no concession to season or geography.

Increasingly efficient global transport networks make it practical to bring food before it spoils from distant places where labor costs are lower. And the penetration of mega-markets in nations from China to Mexico with supply and distribution chains that gird the globe — like Wal-Mart, Carrefour and Tesco — has accelerated the trend.

But the movable feast comes at a cost: pollution — especially carbon dioxide, the main global warming gas — from transporting the food.

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