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  3. Planes may account for only 2 per cent of the world’s carbon emissions, but it is a figure destined to rise. The aviation indust

Planes may account for only 2 per cent of the world’s carbon emissions, but it is a figure destined to rise. The aviation indust

admin2015-04-10  90
问题     Planes may account for only 2 per cent of the world’s carbon emissions, but it is a figure destined to rise. The aviation industry is expanding at a dramatic rate, around 5% a year. Twice as many passengers are likely to be passing through British airports in 2020 compared with today, and three times by 2030.
    As the developed world acknowledges climate change warnings, the carbon emissions from other industries will fall. The aviation industry’s output will therefore account for an even larger percentage of emissions. One calculation, by the Climate Change Research(CCR), suggests the U. K. aviation industry could end up accounting for every gram of our carbon quota by 2040. Such calculations suppose aircraft designers cannot clean up their act, a suggestion firmly rejected by experts who point to a massive research program aimed at cutting fuel use by planes by around 50% by 2020, a move that would also halve their carbon emissions.
    To reach that aim, a key factor will be lightweight composites, materials made of several components, including carbon fibers. These are as strong and flexible as metal but as light as plastic. Planes such as the Airbus A340 are already made of material that is 10 per cent carbon composite. This cuts weight, decreases fuel use and reduces carbon emissions. The next generation of aircrafts, will make even more use of composites: a tremendous saving in weight, fuel and carbon.
    Then there is the simple matter of air traffic control. At present, individual countries have their own routes for aircraft crossing their airspaces. "Essentially aircraft travel on doglegs across Europe, and that is very inefficient in terms of fuel use," said Dr. John Green, of the Royal Aeronautical Society. "We need to rationalize air traffic control so that planes fly in straight, energy-efficient lines, an idea that is now being discussed in the EU. "
    Finally, there is aviation fuel. Making it ecologically friendly poses the greatest challenges of all. Biofuels can be used as petrol and diesel substitutes for cars and lorries, but not in planes. "Biofuel is essentially alcohol, and that burns at the wrong temperature for aircraft engines," says Green. "We can use coal to make kerosene, which we could burn in aircraft engines, but that does not help the issue of global warming, of course. " But this does not stop scientists from dreaming. One idea, put forward by the U. S. geneticist Craig Venter last week, would be to create micro-organisms, fitted with artificial chromosomes, which could convert sunlight into fuels that could be burnt in aircraft. These would not involve burning fossil carbon and would be the perfect green fuel. It is still a far-off prospect but realistic, say biologists.
The experts in aviation industry disapproved the claim by the CCR because
选项 A、the calculation of aviation industry’s carbon emission is based on prediction instead of facts.
B、the figure calculated is much more than the experts in aviation industry expected.
C、airlines are also making great efforts to reduce their oil consumption and carbon emissions.
D、the experts didn’t agree with the way of their calculation of the carbon emissions by planes.
答案C
解析 航空业的专家们不赞成“气候变化研究”小组的说法，因为[A]航空业碳排放量的计算是基于预测而非事实。[B]计算结果比航空业专家们的预期多得多。[C]航空公司也在努力降低油耗和减少碳排放量。[D]专家们不认同“气候变化研究”小组计算飞机碳排放量的方法。根据题干信号词CCR可以快速定位到第二段中关于其对航空业碳排放量的预估。根据第二段最后一句，该计算没有考虑到飞机设计师以及航空公司在减少污染上做出的努力，因此遭到了有关专家的强烈反对，故选[C]。[A]、[B]和[D]均为臆测的混淆选项，文章并未提及，可以很容易排除。
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