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Now listen to part of a lecture on the topic you just read about.
现在来听一段有关你刚刚读到的话题的演讲。
Unfortunately, the arguments of the reading passage are a little out of date.
不幸的是，阅读文章里的观点有些过时了。
Scientists now have new information that shows that none of the ideas the reading passage discusses could account for the Little Ice Age.
科学家们现在有新的信息能证明，阅读文章里讨论的观点没有一个能解释小冰河期。
First, about the Gulf Stream.
首先，关于墨西哥湾流。
Scientists now know that disrupting the Gulf Stream would cause cooling only in Europe and North America,
科学家们现在知道，阻断墨西哥湾流只能引起欧洲和北美变冷，
but the Little Ice Age also affected the Southern hemisphere, in places like New Zealand and Southern Africa for example.
但是小冰河期还能影响南半球，像新西兰和南非这些地方。
Since the disruption of the Gulf Stream cannot explain why these southern areas became colder, it cannot explain the Little Ice Age.
因为墨西哥湾流的中断不能解释这些南部地区的变冷，它也不能解释小冰河期。
Second. the volcanoes theory.
第二，火山理论。
1t's true that if volcanic eruptions put enough dust into the atmosphere, the result can be a cooler climate.
诚然，如果火山爆发释放出足够多的尘土到大气层，会使气候变冷。
But large amounts of volcanic dust in the atmosphere would have also produced striking visual effect that people would have noticed at the time.
但是，同时大气层中大量的火山尘也会产生惊人的视觉效果，人们会注意到。
For example. Dramatically colorful Sunsets or snow being grey or brown instead of white.
就好比，戏剧化多彩的日落，又或者是雪变成了灰色或者棕色而不是白色。
But there are almost no reports of anything like that routinely happening during the Little Ice Age.
但是，在小冰河期，几乎没有任何相关的常规报道。
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.
所以，似乎那个时期的火山爆发不够猛烈，不能释放出降低全球气温所需要的大量尘土。
Third, about forests on farmland stopping the warming greenhouse effect by removing carbon dioxide.
第三，关于耕地上的森林通过去除二氧化碳阻止了气候变暖的温室效应。
There just was not enough time for this effect to work.
时间还不够引起这一效应的产生。
The human population grew back to previous levels fairly quickly,
人口增长回到以前的水平相当快，
which meant that forests were soon being cut down again to clear fields for the crops needed to feed the growing population.
这意味着，森林将很快被再次砍伐以清出土地给增长的人口所需的农作物。
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.
因此，我们知道，阅读文章中所提到的森林，存在的时间还不够长，不足以引起全球气候变冷这个长期效应。
