美国国家公共电台 NPR To Predict Effects Of Global Warming, Scientists Looked Back 20,000 Years

 

ARI SHAPIRO, HOST:

Climate scientists are struggling to figure out how a warming planet will affect different ecosystems¹ like forests, swamps and grasslands³. So researchers looked back at the end of the last ice age to see what might be in store for us. As NPR's Christopher Joyce reports, they suspect some ecosystems could change completely in a century.

CHRISTOPHER JOYCE, BYLINE⁴: Much of the Northern Hemisphere was covered by ice sheets 20,000 years ago. Then the Earth started warming up. By 10,000 years ago, it was warmer by about 7 to 12 degrees Fahrenheit⁵. Ecologist Stephen Jackson says that makes that period of Earth's history much like what greenhouse gases are doing to the Earth now.

STEPHEN JACKSON: The change over the next 100, 150 years is of similar magnitude globally to what we saw during the last ice retreat.

JOYCE: Jackson works for the U.S. Geological Survey. He and a team of more than 40 scientists examined fossil pollen⁶ and vegetation to figure out how that ancient warming affected⁷ various ecosystems. The researchers found huge changes after the ice age. In Jackson's neighborhood in Arizona, for example, it's now desert - cactus⁸ and shrubs⁹ mostly. Fifteen thousand years ago, though...

JACKSON: What we'd see there instead is juniper-pinyon woodland and evergreen¹⁰ woodland - utterly¹¹ different from the vegetation we'd find here.

JOYCE: So as climate changes, some forests may give way to woody shrubs or grassland², or grassland could convert to desert. Writing in the journal Science, the researchers say they can't predict exactly where and how fast these changes will happen. For one thing, the warming now is a lot faster than it was at the end of the ice age.

JACKSON: Instead of that happening over several thousand years, we're cramming¹² all of that climatic change into a century, century and a half.

JOYCE: And their historical record shows a climate going from frigid¹³ to warm. Now it's moving from warm to warmer. That may be different. But Jackson says one thing is likely - more predictability, maybe even ecosystems that are totally new. And that poses challenges for forests, wildlands and even fisheries and for people who depend on them.

JACKSON: That's going to create a great deal of chaos¹⁴, ecological¹⁵ chaos out there as they try to adapt and respond to those changes.

JOYCE: These changes are happening now. Some forests in the southwest are dying and being replaced by smaller plants and shrubs. Ecologist David Breshears at the University of Arizona says it's similar to what happened in the past.

DAVID BRESHEARS: These changes are very temperature-sensitive. And I think that's the most important takeaway message because that's what we're dealing¹⁶ with right now I think in contemporary times.

JOYCE: In the journal Scientific Reports, Breshears and scientists in Australia showed how quickly big changes can happen. A heat wave in western Australia in 2011 caused coral bleaching¹⁷ in the ocean as well as tree deaths, damaging insect outbreaks and die-offs of birds - all very different ecosystems, all responding to a warmer environment. Christopher Joyce, NPR News.

(SOUNDBITE OF BLUE IN GREEN'S "RAINY STREETS")

1 ecosystems   

n.生态系统( ecosystem的名词复数 )

参考例句：

• There are highly sensitive and delicately balanced ecosystems in the forest. 森林里有高度敏感、灵敏平衡的各种生态系统。 来自《简明英汉词典》
• Madagascar's ecosystems range from rainforest to semi-desert. 马达加斯加生态系统类型多样，从雨林到半荒漠等不一而足。 来自辞典例句

2 grassland   

n.牧场，草地，草原

参考例句：

• There is a reach of grassland in the distance.远处是连绵一片的草原。
• The snowstorm swept the vast expanse of grassland.暴风雪袭击了辽阔的草原。

3 grasslands   

n.草原，牧场( grassland的名词复数 )

参考例句：

• Songs were heard ringing loud and clear over the grasslands. 草原上扬起清亮激越的歌声。 来自《现代汉英综合大词典》
• Grasslands have been broken and planted to wheat. 草原已经开垦出来，种上了小麦。 来自《简明英汉词典》

4 byline   

n.署名；v.署名

参考例句：

• His byline was absent as well.他的署名也不见了。
• We wish to thank the author of this article which carries no byline.我们要感谢这篇文章的那位没有署名的作者。

5 Fahrenheit   

n./adj.华氏温度；华氏温度计(的)

参考例句：

• He was asked for the boiling point of water in Fahrenheit.他被问到水的沸点是华氏多少度。
• The thermometer reads 80 degrees Fahrenheit.寒暑表指出华氏80度。

6 pollen   

n.[植]花粉

参考例句：

• Hummingbirds have discovered that nectar and pollen are very nutritious.蜂鸟发现花蜜和花粉是很有营养的。
• He developed an allergy to pollen.他对花粉过敏。

7 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

8 cactus   

n.仙人掌

参考例句：

• It was the first year that the cactus had produced flowers.这是这棵仙人掌第一年开花。
• The giant cactus is the vegetable skycraper.高大的仙人掌是植物界巨人。

9 shrubs   

灌木( shrub的名词复数 )

参考例句：

• The gardener spent a complete morning in trimming those two shrubs. 园丁花了整个上午的时间修剪那两处灌木林。
• These shrubs will need more light to produce flowering shoots. 这些灌木需要更多的光照才能抽出开花的新枝。

10 evergreen   

n.常青树；adj.四季常青的

参考例句：

• Some trees are evergreen;they are called evergreen.有的树是常青的，被叫做常青树。
• There is a small evergreen shrub on the hillside.山腰上有一小块常绿灌木丛。

11 utterly   

adv.完全地，绝对地

参考例句：

• Utterly devoted to the people,he gave his life in saving his patients.他忠于人民，把毕生精力用于挽救患者的生命。
• I was utterly ravished by the way she smiled.她的微笑使我完全陶醉了。

12 cramming   

n.塞满，填鸭式的用功v.塞入( cram的现在分词 )；填塞；塞满；（为考试而）死记硬背功课

参考例句：

• Being hungry for the whole morning, I couldn't help cramming myself. 我饿了一上午，禁不住狼吞虎咽了起来。 来自《简明英汉词典》
• She's cramming for her history exam. 她考历史之前临时抱佛脚。 来自《简明英汉词典》

13 frigid   

adj.寒冷的，凛冽的；冷淡的；拘禁的

参考例句：

• The water was too frigid to allow him to remain submerged for long.水冰冷彻骨，他在下面呆不了太长时间。
• She returned his smile with a frigid glance.对他的微笑她报以冷冷的一瞥。

14 chaos   

n.混乱，无秩序

参考例句：

• After the failure of electricity supply the city was in chaos.停电后，城市一片混乱。
• The typhoon left chaos behind it.台风后一片混乱。

15 ecological   

adj.生态的，生态学的

参考例句：

• The region has been declared an ecological disaster zone.这个地区已经宣布为生态灾难区。
• Each animal has its ecological niche.每种动物都有自己的生态位.

16 dealing   

n.经商方法，待人态度

参考例句：

• This store has an excellent reputation for fair dealing.该商店因买卖公道而享有极高的声誉。
• His fair dealing earned our confidence.他的诚实的行为获得我们的信任。

17 bleaching   

漂白法，漂白

参考例句：

• Moderately weathered rock showed more intense bleaching and fissuring in the feldspars. 中等风化岩石则是指长石有更为强烈的变白现象和裂纹现象。
• Bleaching effects are very strong and show on air photos. 退色效应非常强烈，并且反映在航空象片上。