原文已被隐藏，你可用 快捷键 - 或点击 显示原文 按钮来查看原文
第1段
1 .<-NARRATOR:->Listen to part of a lecture in an environmental science class.
旁白：听一段关于环境科学的讲座。
第2段
1 .<-FEMALE PROFESSOR:->When land gets developed for human use, the landscape changes.
教授：当土地被开发为人类使用，景观就会改变。
2 .We don't see as many types of vegetation, trees, grasses and so forth.
我们不再能看到那么多的植被，树木，草地等等。
3 .This in turn leads to other losses: the loss of animal that once lived there.
这接着就导致了其他损失：那些曾经在那里居住的动物。
4 .Err... but these are the obvious changes, but there are also less obvious changes, like the climate.
但这些都是显著的变化。还有一些变化并不那么显眼，比如气候变化。
5 .One interesting case of this... of changes in the local land use causing changes in climate, specifically the temperature is in Florida.
一个关于当地土地变化导致气候变化，特别是温度变化的有趣例子是在佛罗里达州。
6 .Now what comes to mind when you think of the state of Florida?
现在，当提到佛罗里达州的时候，首先你想到了什么？
第3段
1 .<-MALE STUDENT:->Sunshine, beaches.
学生：阳光，沙滩。
第4段
1 .<-FEMALE STUDENT:->Warm weather, oranges...
学生：暖和的气候，橙子
第5段
1 .<-FEMALE PROFESSOR:->Yes, exactly.
教授：正是如此。
2 .Florida has long had a great citrus industry—large growth of oranges, lemons and the like.
佛罗里达一直以来有很好的柑橘属水果产业，大量种植橙子、柠檬和类似水果。
3 .Florida's winter is very mild; the temperature doesn't often get below freezing.
佛罗里达的冬天非常温和，气温很少会掉到零度以下。
4 .But there are some areas of Florida do freeze.
但佛州的一些地方会达到结冰点。
5 .So in the early 1900’s farmers moved even further south in Florida to areas that were even less likely to freeze.
在二十世纪早期，农民们搬到了佛州南部，那里很少会结冰。
6 .Obviously, freezing temperatures are a danger to the crops.
很明显，低温对农作物是一种威胁。
7 .A bad bout of cold weather... a long spell of frosts... could ruin a farmer’s entire crop.
寒冷气候和冻霜可能毁掉一个农场的所有庄稼。
8 .Anyway, before the citrus growers moved south, much of the land in south Florida was what we call “wetlands.”
无论如何，在柑橘种植者向南迁移之前，南佛罗里达的大部分土地就是我们所说的“湿地”。
9 .Wetlands are areas of marshy... swampy land... areas where water covers the soil, or is present either at or near the surface of the soil, for a large part of the year.
湿地是沼泽区…沼泽的土地……在一年的大部分时间里，水覆盖土壤，或存在于土壤表面或接近土壤表面。
10 .Wetlands have their own unique ecosystems, with plants and animals with special and interesting adaptations.
湿地有自己独特的生态系统，这里的植物和动物都有特别有趣的适应性。
11 .Very exciting, but it's not what we are talking about today.
非常令人兴奋，但已经不是我们今天所谈论的样子了。
12 .Emm... where was I?
嗯⋯⋯我说到哪了？
第6段
1 .<-MALE STUDENT:->Farmers moved south? [rising intonation]
学生：农民移到南部了？
第7段
1 .<-FEMALE PROFESSOR:->Oh, yes. Farmers moved south. But the land was not suitable for farming.
教授：噢，对。农民南下了。但那里的土地不适合耕种。
2 .You can't grow oranges in wetland, so farmers had to transform the wetlands into lands suitable for farming.
不能在湿地上种植柑橘，所以农民们要把湿地转换成一种可以耕种的土地。
3 .To do that, you have to drain the water from the land, move the water elsewhere, and divert the water sources such as rivers.
为了达成这个目的，我们得把水从土地中引出来，把它移到别的地方，使它转而流向其他水源，比如河流。
4 .Hundreds of miles of drainage canals were built in the wetlands.
上百英里的水渠在湿地上挖好了。
5 .Now these areas, the new areas the farmers moved to, used to be warm and unlikely to freeze, however, recently the area has become susceptible to freezes.
现在，那些农民们安顿下来的温和不结冰的地区却在最近开始变得容易冰冻了。
6 .And we are trying to understand why.
我们在试图寻找原因。
第8段
1 .<-FEMALE STUDENT:->Is it some global temperature change or weather pattern like El NiNO or something?
学生：是因为一些全球气温或者气候类型改变吗？比如厄尔尼诺现象？
第9段
1 .<-FEMALE PROFESSOR:->Well, there are two theories.
有两个理论。
2 .One idea, is as you suggest... that major weather patterns... something like El Niño... are responsible.
一个想法是，你所说的一些主要气候现象是主要原因，比如厄尔尼诺。
3 .But the other idea and this is the one that I personally subscribe to, is that the changes in the temperature pattern had been brought about by the loss of wetlands.
但另一个想法，也是我个人比较倾向于的想法，是由湿地的减少而产生的气温变化。
第10段
1 .<-MALE STUDENT:->Well, how would the loss of wetlands make a difference?
学生：为什么湿地的减少会改变气温呢？
第11段
1 .<-FEMALE PROFESSOR:->Well, think about what we've been studying so far.
教授：想想我们之前学过的东西。
2 .We discussed the impact of landscapes on temperature, right?
我们讨论过地貌对于气温的影响，对吧？
3 .What affects does the body of water have on an area?
水体对一个区域有什么影响?
第12段
1 .<-MALE STUDENT:->Oh, yeah. Bodies of water tend to absorb the heat during the day, and then they release the heat at night.
学生：哦，对，水会在白天吸收热量，在晚上再释放出来。
第13段
1 .<-FEMALE PROFESSOR:->Yes, exactly.
教授：对，就是这样。
2 .What you just said is what I want you all to understand.
你刚才说的就是我希望你们都能理解的道理。
3 .Bodies of water release heat—and moisture back into the environment.
水体将热量和水分释放回环境中。
4 .So places near large bodies of water are generally milder, err... slightly warmer than those without water.
所以接近水体的区域，总体来说比没有水的地方气候更温和。
5 .And what I... and others think is that the loss of the wetlands has created a situation where the local temperatures in the area are now slightly different, slightly colder, than they were a hundred years ago before the wetlands were drained.
有人认为，湿地的减少使得当地的温度比100 年前湿地还没有被抽干的时候的低了。
第14段
1 .<-FEMALE STUDENT:->Emm... do we know what the temperature was like back then?
学生：嗯，我们知道之前的温度是多少吗？
第15段
1 .<-FEMALE PROFESSOR:->Well, we were able to estimate this.
教授：嗯，我们可以估算它。
2 .We have data about South Florida's current landscape, emm... the plant cover.
我们有关于佛州南部的地貌⋯⋯嗯，覆盖的植被的数据。
3 .And we were able to reconstruct data about its landscape prior to 1900.
我们可以重新模拟二十世纪前的地貌数据。
4 .Then we enter those data, information about what the landscape look like before and after the wetlands were drained.
然后我输入这些数据，这些关于湿地失水前后的地形的信息
5 .We enter the data into a computer weather model.
我们把数据输入计算机气象模型。
6 .This model can predict temperatures.
这个模型可以预测气温。
7 .And when all the data were entered, an overall cooling trend was predicted by the model.
当所有的数据被输入进去，总体的降温趋势就被模型预测出来了。
第16段
1 .<-FEMALE STUDENT:->How much colder does it get now?
学生：现在气温变冷了多少？
第17段
1 .<-FEMALE PROFESSOR:->Well, actually the model shows a drop of only a few degrees Celsius...
教授：事实上，模型显示仅仅低了摄氏几度...
2 .But this is enough to cause dramatic damage to crops.
但这足够给农作物带来巨大的损失。
3 .If temperatures overnight are already very close to the freezing point, then this drop of just a few degrees can take the temperature below freezing.
如果晚上的温度本来就已经接近结冰点，那么下降几度有可能使温度到达冰点以下。
4 .And freezing causes frosts, which kill crops.
冻冰导致霜冻，这会杀死农作物。
5 .These damaging frosts wouldn't happen if the wetlands were still in existence, just a tiny temperature difference can have major consequences.
如果湿地仍然存在，这些破坏力大的霜冻就不会出现。仅仅是微小的气温差别就会导致严重的后果。