Reading

The little ice age was a period of usually cold temperature in many parts of the world that lasted from about the year 1350 until 1900.

There were unusually harsh winters, and glaciers grew larger in many areas. Scientists have long wondered what caused the Little Ice Age. Several possible causes have been proposed.

First, the cooling may have been caused by disrupting of ocean currents. Before the Little Ice Age, there was a period of unusually warm weather during which glaciers melted. These melted glaciers sent a large amount of cold freshwater into the Gulf Stream, a large ocean current that strongly affects Earth\'s climate. Some scientists believe that this freshwater was enough to temporarily disrupt the Gulf Stream. Such a disruption could have caused the Little Ice Age.

Second, volcanic eruption could have caused the Little Ice Age. When volcanoes erupt, they send dark clouds of dust and sulfur gas into the atmosphere. These clouds, which can spread over great areas, block some sunlight from reaching Earth\'s surface. This can decrease the global temperatures. Scientists know of several volcanic eruptions that took place during the Little Ice Age. Third, Substantial decreases in human populations may have contributed indirectly to the cooling of the climate. For a variety of reasons (disease, warfare, social disruption), the human population just before the Little Ice Age and during the early part of it was lower than it had been in a long time. Forest trees started growing on fields that were no longer used for agriculture. Since trees absorb carbon dioxide, a greenhouse gas, they decrease the greenhouse effect that keeps Earth warm. With more forest trees absorbing carbon dioxide, Earth became cooler.

Listening

Unfortunately, the arguments of the reading passage are a little out of date. Scientists now have new information that shows that none of the ideas the reading passage discusses could account for the Little Ice Age.First, about the Gulf Stream. Scientists now know that disrupting the Gulf Stream would cause cooling only in Europe and North America, but the Little Ice Age also affected the Southern hemisphere, in places like New Zealand and South Africa for example. Since the disruption of the Gulf Stream cannot explain why these southern areas became colder, it cannot explain the Little Ice Age.

Second, the volcanoes theory. It’s true that if volcanic eruptions put enough dust into the atmosphere, the result can be a cooler climate. But large amounts of volcanic dust in the atmosphere would have also produced striking visual effect that people would have noticed at the time. For example, dramatically colorful sunsets or snow being grey or brown instead of white. But there are almost no reports of anything like that routinely happening during the Little Ice Age. So it seems that the volcanic eruptions during that period were simply not strong enough to release the large amounts of dust needed to lower global temperatures. Third, about forests on farmland stopping the warming greenhouse effect by removing carbon dioxide. There just was not enough time for this effect to work. The human population grew back to previous levels fairly quickly, which meant that forests were soon being cut down again to clear fields for the crops needed to feed the growing population. As a result, we know that the forests mentioned in the reading passage were not there long enough to cause the long‐term global cooling of the climate.

一、阅读听力要点概括

Reading Passage

1、The cooling may have been caused by disrupting of ocean currents.

2、Second, volcanic eruption could have caused the Little Ice Age.

3、Third, Substantial decreases in human populations may have contributed indirectly to the cooling of the climate.

Lecture

1、The Gulf Stream would cause cooling disrupting only in Europe and North America, but the Little Ice Age also affected the Southern hemisphere.

2、Large amounts of volcanic dust in the atmosphere would have also produced striking visual effects that people would have noticed at the time. But there are almost no reports of anything like that routinely happening during the Little Ice Age.

3、There was not enough time for forests on farmland to stop the warming greenhouse effect by emoving carbon dioxide.

二、范文逐段赏析

Paragraph 1

In the reading passage, the author claims that the cause of the Little Ice Age was due to three main reasons. The lecturer, however, refutes the writer’s opinion one by one with strong arguments.

此段功能

首段是总领段，指出了文章与讲座存在不同观点，为接下来的论述做好了铺垫。

此段结构

此段是并列结构，提出了双方争论的焦点。

Paragraph 2

Firstly, the passage argues that the Gulf Stream formed in the previous warm period was responsible for the appearance of the unexpected Little Ice Age. Yet, the speaker argues that the so‐called Gulf Stream only contributed to the cooling weather in Northern hemisphere while Little Ice Age took place all over the world. Thus, global Little Ice Age cannot be attributed to the Gulf Stream in some parts of the planet like New Zealand and South Africa.

此段功能

此段提出阅读材料与演讲中的第一个矛盾点。阅读材料认为之前暖季出现的墨西哥湾洋流是导致意外小冰期出现的原因。然而演讲中反驳道，墨西哥湾洋流只可能导致北半球的冷气候，而小冰期事实上在全球范围内都有发生，因此在新西兰和南非等地的小冰期无从解释。

此段结构

此段是并列结构，分别论述。

Paragraph 3

Next, according to the reading material, dust and sulfur gas caused by volcanic eruptions would block sunlight, and thus resulted in the Little Ice Age. The lecturer, however, holds that volcanic eruptions should have led to other visual phenomena than cooling weather, like colorful sunsets or grey snow. But unfortunately none of them were reported. If this is taken into consideration, volcanic eruptions do not seem strong enough to release the large amounts of dusts needed to lower global temperatures.

此段功能

在此段中阅读材料指出另一个观点，即火山爆发引起的灰尘气体等遮住了太阳，进而导致了小冰期。而演讲中指出，如果火山爆发足够巨大，那么应该会有相关报道。因为历史上并没有此方面报道，则说明火山爆发没有那么大规模，也就不可能导致将整个地球温度降低的强度。

此段结构

此段并列结构，就文章与演讲中的不同观点进行论证。

Paragraph 4

Last but not least, the writer states that the substantial decrease in human population may cause the unusual Little Ice Age. Again the speaker argues that there was not enough time for this effect to work. Forests were soon being cut down to meet the need of growing back of human forests. The short‐time appearance of forests should not take the responsibility of the Little Ice Age.

此段功能

此段指出，阅读材料认为人口的减少也可能导致小冰期。然而演讲中指出，这样的影响会花费很长的时间，树木被砍伐得很快，短期的树林不可能导致小冰期。

此段结构

此段并列结构，分别论证了阅读材料和演讲中的矛盾点。

三、范文全篇总评

1、逻辑结构

全文采用总‐分的结构，在文章第一段先提出了文章与演讲观点的冲突，然后分三个方面分别一一指出阅读材料的观点，并陈述了演讲中的观点进行了论证反驳。

2、语言表达

在文章的第二段，有两个词组值得注意。

….the speaker argues that the so‐called Gulf Stream only contributed to the cooling weather in Northern hemisphere……

…global Little Ice Age cannot be attributed to the Gulf Stream in some parts of the planet…

其中，contribute to 意为“导致，促成，有助于”等。而 attribute to 意为“把…归因于…..”其中，原因部分放在 to 的后面，而在文中，即为 attribute Little Ice Age to the Gulf Stream。