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Argument47 第7篇 让砖头来得更猛烈些吧!
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作者:寄托家园作文版普通用户 共用时间:63分23秒 320 words
从2006年5月15日11时8分到2006年5月15日12时63分
------题目------
Scientists studying historical weather patterns have discovered that in the mid-sixth century, Earth suddenly became significantly cooler. Although few historical records survive from that time, some accounts found both in Asia and Europe mention a dimming of the sun and extremely cold temperatures. Either a huge volcanic eruption or a large meteorite colliding with Earth could have created a large dust cloud throughout Earth's atmosphere that would have been capable of blocking enough sunlight to lower global temperatures significantly. A large meteorite collision, however, would probably create a sudden bright flash of light, and no extant historical records of the time mention such a flash. Some surviving Asian historical records of the time, however, mention a loud boom that would be consistent with a volcanic eruption. Therefore, the cooling was probably caused by a volcanic eruption.
------正文------
The argument asserts that the cooling of the Earth in the mid-sixth century was probably cause by a volcanic eruption. To support this conclusion, the argument demonstrates some relative clues, including a dimming of the sun, a loud boom, and the absence of a sudden bright flash, according to some surviving historical records. However, the current information, which is provided by the argument, cannot powerfully back up the conclusion.
First of all, no evidence indicates that the cooling is mainly caused by the dimming of the sun. Though some accounts found in Asia and Europe mention a dimming of the sun and extremely cold temperatures, the global situation in the mid-sixth century is not clear, since few historical records survive from that time. The sunlight might have been brighter in other areas, and the extremely cold temperatures in Asia and Europe could have been induced by other factors, such as the internal variability of the Earth, the change of greenhouse gases, and the characteristics of the land surface. All can be inferred from those historical records is that the dimming of the sun might have been a reason of the extremely cold temperatures in Asia and Europe, but whether the dimming is a main cause of the global cooling still remains a question.
Besides, even if the cooling of the Earth is significantly influenced by the dimming of the sun, it is unreasonable to assume that the dimming of the sun in Asia and Europe was induced by a large dust cloud. Although a large dust cloud throughout Earth's atmosphere that would have been capable of blocking enough sunlight to lower global temperatures significantly, no additional information mentions such a dust cloud, and the dimming of the sun could have been caused by other events, for example, the internal alternation of the sun. Thus it is too arbitrary to attribute the dimming of the sun to a large dust cloud, which might have been caused by a huge volcanic eruption or a large meteorite colliding with Earth.
Furthermore, even if the dimming of the sun was related to a large dust cloud, it is uncertain that the dust cloud was exactly caused by a volcanic eruption. Although no extant historical records of the time mention a sudden bright flash of light, which would probably be created by a large meteorite collision, the possibility of the meteorite collision, which can also cause a large dust cloud, cannot be ignored, since few records survive today. Moreover, though some surviving Asia historical records mention a loud boom that would be consistent with a volcanic eruption, a large meteorite collision would also induce such a loud boom. Even if the boom was exactly caused by a volcanic eruption, no evidence indicates that the eruption is powerful enough to create a dust cloud throughout the global atmosphere. Additionally, the dust cloud could have been cause by other factors except an eruption or a collision, such as earthquakes, hurricanes, and dust storms. Therefore, it is unwise to claim that the large dust cloud was induced by a large volcanic eruption.
In conclusion, the causes of the global cooling in the mid-sixth century are still unknown, and neither the happening of a large dust cloud nor the existence of a large volcanic eruption can be attested. As a result, the conclusion of the argument that the cooling was caused by a volcanic eruption is unverified and unreasonable. |
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