题型：阅读理解 题类：常考题 难易度：普通
江苏省盐城中学2016-2017学年高二下学期英语5月阶段性检测试卷
For years, scientist and others concerned about climate change have been talking about the need for carbon capture and storage(CCS).
That is the term for removing carbon dioxide from, say, a coal-burning power plant's smokestack and pumping it deep underground to keep it out of the atmosphere, where it would otherwise contribute to global warming.
However, currently, only one power plant in Canada captures and stores carbon on a commercial scale (and it has been having problems). Among the concerns about storage is that carbon dioxide in gaseous or liquid form that is pumped underground might escape back to the atmosphere. So storage sites would have to be monitored, potentially for decades or centuries.
But scientists at Lamont-Doherty Earth Observatory at Columbia University and other institutions have come up with a different way to store CO2 reacts with the rock to form a mineral call calcite(方解石). By turning the gas into stone, scientists can lock it away permanently. Volcanic rocks called basalts(玄武岩) are excellent for his process, because they are rich in calcium, magnesium and iron, which react with CO2.
The project called CarbFix started in Iceland, 2012, when the scientists pumped about 250 tons of carbon dioxide, mixed with water, about 1,500 feet down into porous basalt. Early sings were encouraging: The scientists found that about 95 percent of the carbon dioxide was changed into calcite. And even more importantly, they wrote, the change happened relatively quickly—in less than two years.
“It's beyond all our expectations,” said Edda Aradottir, who manages the project. Rapid change of the CO2 means that a project would probably have to be monitored for a far shorter time than a more conventional storage site.
There are still concerns about whether the technology will prove useful in the fight against global warming. For one thing, it would have to be scaled up enormously. For another, a lot of water is needed—25 tons of it for every ton of CO2—along with the right kind of rock.
But the researchers say that there is enough porous basaltic rock in Iceland, including in the ocean floors and along the margins of continents. And sitting a storage project in or near the ocean could potentially solve the water problem at the same time, as the researchers say seawater would work just fine.
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