Not every breakthrough sounds like rocket science. Simple but novel ideas can work wonders. A radical new way to tackle clima

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问题    Not every breakthrough sounds like rocket science. Simple but novel ideas can work wonders.
   A radical new way to tackle climate change is to pump CO2 into the volcanic rock under Iceland and speed up a natural process where the basalts (玄武岩) react with the gas to form carbonate minerals, which make up limestone. Such carbon capture and storage (CCS) is thought to be essential to halting global warming.
   The Iceland project has already been increased in scale to bury 10, 000 tons of CO2 a year and the basalt rocks used are common globally, forming the floor of all the oceans and parts of the land too. One potential challenge for the new technique is that it requires large amounts of water: 25 tonnes for each tonne of CO2 buried. But seawater could be used, which would be in plentiful supply at coastal sites.
   The research, called the Carbfix project, took place at Iceland’s Hellisheidi power plant, the world’s largest geothermal facility. The plant pumps up volcanically heated water to run electricity-generating turbines but this also brings up volcanic gases, including carbon dioxide and nasty-smelling hydrogen sulphide.
   The researchers re-injected 230 tonnes of the gas, which was dissolved in water to prevent it from escaping, down into the basalt to a depth of 400m-500m. They used tracer chemicals to show that over 95% of CO2 was turned into stone within two years.
   In conventional CCS, the CO2 is stored as a gas in sedimentary rocks such as exhausted oil fields under the North Sea. Unlike basalt, these rocks lack the minerals needed to convert CO2 into stone. Such sedimentary reservoirs could potentially leak and therefore have to be monitored, which adds to costs. Unlike the basalt-based CCS, conventional CCS also requires the CO2 to be separated from the mix of gases emitted by power stations and industrial plants, which is expensive.
   Stuart Haszeldine, a professor of CCS, said: "It may well provide a low-cost and very secure remedy for parts of the world where the suitable rocks exist. But other existing propositions need to be used, because the problem to be solved of millions of tonnes of CO2 emissions per year worldwide is immense and no single remedy is anywhere near big enough or fast enough."
   Other innovative approaches to CCS are being explored, including a project using fuel cells to make capturing CO2 cheaper and one from Ford which uses CO2 to make foam for use in their vehicles. Groups are also working on chemical advances to capture CO2 more easily.
The problems with conventional CCS include the following except______.

选项 A、an extremely high cost
B、potential leaks to be monitored
C、separation of CO2 from other gases
D、consumption of large amounts of water

答案D

解析 第六段没有提到使用大量的水。
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