【you are not alone】小组提纲作业 Argument47

Luise8891UID: 2906459

47Scientists 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.

Luise8891UID: 2906459

)the few historical records are insufficient to prove the assumption that either a huge volcanic eruption or a large meteorite colliding with Earth created this phenomenon.除了这两种原因之外是否就不再存在其他可能性了，论者没有告诉我们是否只有这两种情况会造成全球气温突然下降.
2)Even granted that it was either a huge colcanic eruption or a large meteority colliding with earth that gave rise to the cooling of temperatures, the arguer fails to convince us that the cooling was caused by a volcanic eruption.

刘文奇UID: 2850560

研究历史上气候变化的学者发现在六世纪中叶，地球突然变冷了很多。尽管那个时期很少有历史记录被保存下来，一些在亚洲和欧洲所发现的记录提到了太阳变暗和极度的寒冷。要么是巨大的火山喷发，要么是撞击地球的大型小行星导致地球大气形成一大片尘埃云层，这阻止了一定的阳光导致全球温度显著下降。然而，大型小行星的撞击可能产生突然的强闪光，而现存的那时的历史记录中没有提到过这样的闪光。然而那时遗留下来的一些亚洲历史纪录提到过与一次火山喷发相一致的巨大隆隆声。因此，那时的温度下降多半是火山喷发导致的。
一）        太阳变暗和极度的寒冷并不能说明变冷。
二）        隆隆声不一定是说明是火山喷发。
三）        没有记录强光，不一定没有。