2022-06-24 10:06:14 来源:中国教育在线
一、Reducing Carbon Dioxide in the Atmosphere 听力原文:
As we saw in the last lecture, a major cause of climate change is the rapid rise in the level of carbon dioxide in the atmosphere over the last century.
If we could reduce the amount of CO2, perhaps the rate of climate change could also be slowed down.
One potential method involves enhancing the role of the soil that plants grow in, with regard to absorbing CO2.
Rattan Lal, a soil scientist from Ohio State University, in the USA, claims that the world's agricultural soils could potentially absorb 13 per cent of the carbon dioxide in the atmosphere - the equivalent of the amount released in the last 30 years.
And research is going on into how this might be achieved.
Lal first came to the idea that soil might be valuable in this way not through an interest in climate change, but rather out of concern for the land itself and the people dependent on it.
Carbon-rich soil is dark, crumbly and fertile, and retains some water.
But erosion can occur if soil is dry, which is a likely effect if it contains inadequate amounts of carbon.
Erosion is of course bad for people trying to grow crops or breed animals on that terrain.
In the 1970s and'80s, Lal was studying soils in Africa so devoid of organic matter that the ground had become extremely hard, like cement.
There he met a pioneer in the study of global warming, who suggested that carbon from the soil had moved into the atmosphere.
This is now looking increasingly likely.
Let me explain.
For millions of years, carbon dioxide levels in the atmosphere have been regulated, in part, by a natural partnership between plants and microbes - tiny organisms in the soil.
Plants absorb CO2 from the air and transform it into sugars and other carbon-based substances.
While a proportion of these carbon products remain in the plant, some transfer from the roots to fungi and soil microbes, which store the carbon in the soil.
The invention of agriculture some 10,000 years ago disrupted these ancient soil-building processes and led to the loss of carbon from the soil.
When humans started draining the natural topsoil, and ploughing it up for planting, they exposed the buried carbon to oxygen.
This created carbon dioxide and released it into the air.
And in some places, grazing by domesticated animals has removed all vegetation, releasing carbon into the air.
Tons of carbon have been stripped from the world's soils - where it's needed - and pumped into the atmosphere.
So what can be done?
Researchers are now coming up with evidence that even modest changes to farming can significantly help to reduce the amount of carbon in the atmosphere.
Some growers have already started using an approach known as regenerative agriculture.
This aims to boost the fertility of soil and keep it moist through established practices.
These include keeping fields planted all year round, and increasing the variety of plants being grown.
Strategies like these can significantly increase the amount of carbon stored in the soil, so agricultural researchers are now building a case for their use in combating climate change.
One American investigation into the potential for storing CO2 on agricultural lands is taking place in California.
Soil scientist Whendee Silver of the University of California, Berkeley, is conducting a first-of-its-kind study on a large cattle farm in the state.
She and her students are testing the effects on carbon storage of the compost that is created from waste - both agricultural, including manure and cornstalks, and waste produced in gardens, such as leaves, branches, and lawn trimmings.
In Australia, soil ecologist Christine Jones is testing another promising soil-enrichment strategy.
Jones and 12 farmers are working to build up soil carbon by cultivating grasses that stay green all year round.
Like composting, the approach has already been proved experimentally;
Jones now hopes to show that it can be applied on working farms and that the resulting carbon capture can be accurately measured.
It's hoped in the future that projects such as these will demonstrate the role that farmers and other land managers can play in reducing the harmful effects of greenhouse gases.
For example, in countries like the United States, where most farming operations use large applications of fertiliser, changing such long-standing habits will require a change of system.
Rattan Lal argues that farmers should receive payment not just for the corn or beef they produce, but also for the carbon they can store in their soil.
Another study being carried out ...
二、Reducing Carbon Dioxide in the Atmosphere 听力中文翻译:
正如我们在上一次演讲中所看到的,气候变化的一个主要原因是上个世纪大气中二氧化碳水平的迅速上升
如果我们能够减少二氧化碳的排放量,也许气候变化的速度也可以减缓
一种可能的方法是增强植物生长的土壤在吸收二氧化碳方面的作用
美国俄亥俄州立大学(Ohio State University)的土壤科学家拉坦·拉尔(Rattan Lal)声称,世界农业土壤可能吸收大气中13%的二氧化碳,相当于过去30年释放的二氧化碳量
目前正在研究如何实现这一目标
拉尔首先想到土壤的价值,不是因为对气候变化感兴趣,而是出于对土地本身和依赖土地的人民的关注
富含碳的土壤是黑色的、易碎的和肥沃的,并且保留了一些水分
但是,如果土壤干燥,就会发生侵蚀,如果土壤含碳量不足,可能会产生影响
侵蚀当然对试图在该地区种植作物或繁殖动物的人不利
在20世纪70年代和80年代,拉尔研究了非洲的土壤,因为土壤中缺乏有机物质,以至于地面变得非常坚硬,就像水泥一样
在那里,他遇到了一位全球变暖研究的先驱,他认为土壤中的碳已经进入了大气
现在看来,这种可能性越来越大
让我解释一下
数百万年来,大气中的二氧化碳水平在一定程度上是由植物和微生物——土壤中的微生物——之间的自然伙伴关系调节的
植物从空气中吸收二氧化碳并将其转化为糖和其他碳基物质
虽然这些碳产物中有一部分留在植物中,但一些从根转移到真菌和土壤微生物中,这些微生物将碳储存在土壤中
大约一万年前,农业的发明破坏了这些古老的造土过程,导致土壤中碳的流失
当人类开始排干天然表层土并将其翻耕种植时,他们将埋藏的碳暴露在氧气中
这产生了二氧化碳并释放到空气中
在一些地方,家畜放牧已经清除了所有植被,将碳释放到空气中
全世界需要碳的地方,有成吨的碳被从土壤中剥离出来,并注入大气
那么我们能做些什么呢?
研究人员现在正在拿出证据,证明即使对农业进行适度的改变,也能显着帮助减少大气中的碳含量
一些种植者已经开始使用一种称为再生农业的方法
这旨在通过既定的做法提高土壤肥力并保持土壤湿润
这些措施包括全年种植农田,以及增加正在种植的植物种类
像这样的策略可以显着增加土壤中储存的碳量,因此农业研究人员现在正在构建一个利用这些策略应对气候变化的案例
美国正在加利福尼亚州进行一项关于农业用地储存二氧化碳潜力的调查
加州大学伯克利分校的土壤科学家温迪·西尔弗正在该州的一个大型养牛场进行首次此类研究
她和她的学生正在测试由农业废物(包括粪肥和玉米秸秆)以及花园中产生的废物(如树叶、树枝和草坪修剪物)产生的堆肥对碳储存的影响
在澳大利亚,土壤生态学家克里斯汀·琼斯正在测试另一种有希望的土壤富集策略
琼斯和12位农民正在通过种植全年保持绿色的草来增加土壤碳
就像堆肥一样,这种方法已经被实验证明了;
琼斯现在希望证明它可以应用于工作农场,并且由此产生的碳捕获可以准确测量
人们希望,今后此类项目将展示农民和其他土地管理者在减少温室气体有害影响方面可以发挥的作用
例如,在美国这样的国家,大多数农业经营都使用大量化肥,改变这种长期存在的习惯需要改变制度
RattanLal认为,农民不仅应该为他们生产的玉米或牛肉获得报酬,还应该为他们可以在土壤中储存的碳获得报酬
正在进行的另一项研究
三、Reducing Carbon Dioxide in the Atmosphere 听力问题:
Question 31-40
Complete the notes below.
Write ONE WORD ONLY for each answer.The use of soil to reduce carbon
dioxide (CO2)in the atmosphere
Rattan Lal:
· Claims that 13% of CO2 in the atmosphere could be absorbed by agricultural soils
· Erosion is more likely in soil that is
· Lal found soil in Africa that was very
· It was suggested that carbon from soil was entering the atmosphere
Soil and carbon:
· plants turn CO2 from the air into carbon-based substances such as
· some CO2 moves from the of plants to microbes in the soil
· carbon was lost from the soil when agriculture was invented
Regenerative agriculture:
· uses established practices to make sure soil remains fertile and
· eg through year-round planting and increasing the of plants that are grown
California study:
· taking place on a big farm
· uses compost made from waste from agriculture and
Australia study:
· aims to increase soil carbon by using that are always green
Future developments may include:
· reducing the amount of fertilizer used in farming
· giving farmers for carbon storage, as well as their produce
四、Reducing Carbon Dioxide in the Atmosphere 听力答案:
31.dry
32.hard
33.sugar / sugars
34.roots
35.moist / damp / wet
36.variety
37.cattle
38.gardens / gardening
39.grasses
40.payment / payments / money
五、Reducing Carbon Dioxide in the Atmosphere 听力答案解析
31. dry 根据题干中的erosion, soil定位根据本题的前后内容,考生可以预判答案的词性为形容词或动词的过去分词录音中提到but erosion can occur if soil is dry本题在同义转换上存在难点:卷面的“more likely”表示可能性,录音中用的则是“if”,同样表示可能性故答案为dry
32. hard 根据题干中的soil in Africa定位与上一题相同,本题预判的答案词性为形容词或动词的过去分词录音中提到“…that the ground had become extremely hard…”其中ground与soil为同义替换;extremely与very为同义替换故答案为hard
33. sugar/sugars 根据题干中的plants, carbon-based substances定位根据本题上下文,考生可以预判出答案应该是某一种具体的物质录音中提到“plants absorb CO2 from the air and transform it into sugars and other carbon-based substances…”其中transform与turn为同义转换本题在同义转换上存在难点:卷面的举例短语“such as”在录音中没有直接对应的转换词,而是用“sugars and other…substances”这个结构表示糖是若干种被转换而成的物质之一;卷面空格前的“carbon-based substances”在录音中出现在了考点词的后面,这种倒置的现象在雅思听力考试中很常见,考生应该警惕故答案为sugar/sugars
34. roots 根据题干中的microbes定位根据本题的上下文考生应该很容易预判答案为植物的某一部分录音中提到“…some transfer from the roots to fungi and soil microbes…”其中transfer与move为同义替换故答案为roots
35. moist/damp/wet 根据题干中的established practices定位根据空格前的“…fertile and…”,考生应该可以预判出答案为描述土壤性质的形容词录音中提到“…this aims to boost the fertility of soil and keep it moist through established practices…”其中,keep与remain为同义替换本题在同义转换上存在难点:卷面的形容词“fertile”在语音中被转换为名词“fertility”;卷面空格前的“established practice”再次被倒置到了答案词的后面由于雅思听力考试在部分填空题中允许考生填写考点词的近义词,这道题考生也可以写“damp”或“wet”,但我们不建议大家这么做,因为考生对于哪些词是官方接受的近义词并不清楚,这么做有被判错的风险故本题答案为moist/damp/wet
36. variety 根据题干中的year-round planting, increasing定位本题考生只能预判答案为名词词性录音中提到“…keeping fields planted all-year-round and increasing the variety of plants being growing…”由于卷面考点词前的“increasing”在录音中没有被转换,本题相对简单
37. cattle 根据题干中的farm定位根据上下文信息考生应该可以预测本题的答案应该是名词或形容词词性,修饰“farm”录音提到“…is conducting a first-of-its-kind study on a large cattle farm in the state…”其中large与big为同义替换故答案为cattle
38. gardens/gardening 根据题干的compost, waste定位本题的上下文告诉我们,答案是与“agriculture”并列的一个名词本题的难度比较大,因为录音中出现了多个“and”结构,考生容易混淆当录音中出现多个并列结构时,考生一定要区分并列的层次录音中提到“She and her students are testing the effects on carbon storage of the compost that is created from waste – both agricultural, including manure and cornstalks, and waste produced in gardens, such as leaves, branches, and lawn trimmings.”这句话中有两层并列结构:第一层是“agricultural waste”与“waste produced in gardens”的并列;第二层则是在第一层的下面“manure and cornstalks”从属与“agricultural waste”,而“leaves, branches, and lawn trimmings”则是从属于“waste produced in gardens”题目要填写的是与“agriculture”并列的名词,因此答案自然就是“gardens”,或者其近义词“gardening”
39. grasses 根据题干中的soil carbon定位本题的答案预判为名词,并且是“常绿的”录音中提到“Jones and 12 farmers are working to build up soil carbon by cultivating grasses that stay green all year round.”其中build up与increase为同义转换;always与all year round为同义转换故答案为grasses
40. payment/payments/money 根据题干中的farmers, their produce定位本题的答案预判为名词录音中提到“…farmers should receive payment not just for corn or beef they produce, but also for the carbon they can store in their soil…”本句首先在句子结构上与卷面不同,卷面的“giving farmers sth.”在录音中被转换成了“farmers receive sth.”另外,卷面的并列结构在录音中发生了颠倒:卷面是“A as well as B”,而录音中是“not just B but also A”结构这样的转换在考试中并不罕见,考生应做好准备本题也允许考生填写“payment”的近义词“money”故本题答案为payment/payments/money
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