Argument47 【CSMY作文互改小组】请狂拍，必回拍

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Argument47 【CSMY作文互改小组】第五次作业

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.

提纲：
1.      可能是小型星撞击地球导致地球温度下降。记录丢失的原因有很多。
2.      巨大的隆隆声不一定是火山爆发发出的。
3.      作者未考虑其他可能导致地球温度下降的原因。
In this argument, the author cites the fact that a large meteorite is not attributed to the cooling of the earth because of no such flash mentioned in the extant historical records, and that a volcanic eruption contributes to the cooling of the earth, in that a loud sound consistent with a volcanic eruption was reported. Based primarily on the evidence, the author asserts that a volcanic eruption results in the cooling of the earth. Nonetheless, the author’s argument relies on a large majority of indecisive assumption which render it entirely indefensible as it stands.

First of all, since no extant historical records are reported the flash created by a large meteorite when it collided with earth, the author arbitrarily infer that a large meteorite is not attributive to the cooling of the earth. It is wholly possible that a large meteorite actually collided with the earth and the earth became cooler after this occurrence, but the records are destroyed because of war or lost because the flash solely took place at the areas such as South Pole where people cannot live or write. In short, without considering these facets, the author cannot hastily substantiate the conclustion.

Furthermore, the author fails to establish strong correlation between a volcanic eruption and a loud boom. They take place by coincidence but there is no evidence to prove that there exists firm relationship between them. Perhaps a loud boom is not brought by a volcanic eruption, instead of other alternatives, such as thunder. With insufficient evidence, the author has trouble proving the conclusion that volcanic eruption leads to the cooling.

The author simply assumes that a volcanic eruption is the solely available reason of the cooling. Nonetheless, this is often not the case. A variety of other causes should be taken into account to better bolster the conclusion. For instance, the nuclear reaction of the sun was not active as before in the mid-sixth century, so there is so much sun arrived at the surface of the earth. It might also be the case that another huge planet coincidently pass through the earth and sun and prevent the light of sun from reaching the earth. Therefore, the author’s assumption that only a large meteorite and a volcanic eruption result in the cooling is not convincing.

Overall, the conclusion that the cooling of the earth was possibly resulted from a volcanic eruption seems sound at first glance. Nevertheless, before any conclusion was drawn, the author should provide better proof in reference to the strong correlation between a volcanic eruption and a loud boom. Also, it would be useful to include particular information about other possible causes of the cooling of the earth.