万物简史(MP3+中英字幕) 第380期:进入对流层(21)
日期:2018-03-21 23:04

(单词翻译:单击)

Altogether there is about twenty thousand times as much carbon locked away in the Earth's rocks as in the atmosphere. Eventually much of that limestone will end up feeding volcanoes, and the carbon will return to the atmosphere and fall to the Earth in rain, which is why the whole is called the long-term carbon cycle. The process takes a very long time—about half a million years for a typical carbon atom—but in the absence of any other disturbance it works remarkably well at keeping the climate stable.
总的来说,被关在地球岩石里的碳,大约相当于大气里的2000倍。那些灰岩中的很大一部分最终会成为火山的原料,破将回到大气层,以雨的形式落在地球上。因此,整个过程被称之为长时碳循环。该过程要花很长的时间才完成——对一个普通的碳原子来说,大约要花50万年,在没有别的因素干扰的情况下,这对保持气候稳定很起作用。
the ocean

Unfortunately, human beings have a careless predilection for disrupting this cycle by putting lots of extra carbon into the atmosphere whether the foraminiferans are ready for it or not. Since 1850, it has been estimated, we have lofted about a hundred billion tons of extra carbon into the air, a total that increases by about seven billion tons each year. Overall, that's not actually all that much. Nature—mostly through the belchings of volcanoes and the decay of plants—sends about 200 billion tons of carbon dioxide into the atmosphere each year, nearly thirty times as much as we do with our cars and factories. But you have only to look at the haze that hangs over our cities to see what a difference our contribution makes.
不幸的是,人类却随意打乱这个循环,把大量额外的碳排放到大气里,不顾有孔虫是否有了准备。据估计,自1850年以来,我们已经额外向空气里排放了大约1000亿吨碳,这个数字又以每年大约70亿吨的速度增加。总的来说,那实际上不算很多。大自然——主要通过火山喷发和树木腐烂——大约每年向大气里投放2000亿吨二氧化碳,差不多是我们的汽车和工厂排放量的30倍。但是,你只要看一眼我们雾蒙蒙的城市或者科罗拉多大峡谷,有时候甚至是多佛尔的白垩,你就会明白,我们的参与造成了多大的差别。
We know from samples of very old ice that the "natural" level of carbon dioxide in the atmosphere—that is, before we started inflating it with industrial activity—is about 280 parts per million.
我们从非常古老的冰样得知,大气里二氧化碳的“自然”浓度——也就是说,在我们的工业活动开始雪上加霜之前的浓度——大约是百万分之二百八十。

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重点单词
  • typicaladj. 典型的,有代表性的,特有的,独特的
  • predilectionn. 偏好
  • decayv. (使)衰退,(使)腐败,腐烂 n. 衰退,腐败,腐
  • limestonen. 石灰石
  • eventuallyadv. 终于,最后
  • contributionn. 贡献,捐款(赠)
  • carelessadj. 粗心的,疏忽的 n. 不关心的,粗心的[反]a
  • overalladj. 全部的,全体的,一切在内的 adv. 总的来说
  • stableadj. 稳定的,安定的,可靠的 n. 马厩,马棚,一批