VOA标准英语2011--The Science of Climate Change

The Science of Climate Change

Climate negotiators are meeting in Durban, South Africa beginning from November 28-December 9 to discuss the planet's changing climate.

The first decade of this century was the hottest on record.

Polar ice is melting.

Global sea levels are rising.

And the vast majority of scientists attribute the changes to greenhouse gases, both natural from water vapor¹ and man-made from burning fossil fuels, that trap heat in the lower atmosphere.

"Since roughly the 1850s or so, we've seen an increase globally of about eight-tenths of a degree Celsius², so that's roughly 1.4 degrees Fahrenheit," said Todd Sanford, a climate scientist at the Union of Concerned Scientists in Washington.

A one-degree difference is not noticeable in daily temperatures, but a one-degree change in global average temperature is significant.

"One way to put that in perspective is that in the last Ice Age when there was, you know, a mile of ice above much of North America, the temperature difference between then and now was only roughly five or six degrees Celsius," Sanford said.

Alden Meyer, the director of climate strategy and policy at the Union of Concerned Scientists, says global warming affects weather and water cycles.

"You have increased flooding and extreme downpours combined with droughts and desertification in some regions of the world. So there's tremendous variability here, and we're seeing that with extreme weather events on the increase, not only here in the U.S. but around the world," Meyer said.

A U.N. report shows that climate change hits poorer countries hardest.

William Orme with the United Nations Development Program explains:

"They tend to be arid³, they tend to be rural, and they tend to be therefore most vulnerable to extreme weather events, drought, typhoons and deteriorating⁴ productivity of their soil resources, forest resources and fisheries," Orme said.

And global efforts to curb⁵ emissions⁶ and slow change have not helped yet. Again climate scientist Todd Sanford:

"Last year saw the largest single increase in history to the largest emissions amounts," Sanford said.

NASA satellite evidence shows solar fluctuations⁷ have only a slight impact on global temperatures.

And while the vast majority of climate scientists agree that human activities play a role in climate change, they are not certain how that affects the planet.

Fred Singer is a well known climate change skeptic⁸. He says there is not enough evidence to link human activities, climate change and environmental impacts.

"Supposing the other side is wrong? They are forcing us to make tremendous economic sacrifices which will induce poverty in the world," Singer said.

Other climate change scientists counter that argument, saying greener technologies can be viable⁹ -- environmentally and economically.

1 vapor   

n.蒸汽，雾气

参考例句：

• The cold wind condenses vapor into rain.冷风使水蒸气凝结成雨。
• This new machine sometimes transpires a lot of hot vapor.这部机器有时排出大量的热气。

2 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。

3 arid   

adj.干旱的；(土地)贫瘠的

参考例句：

• These trees will shield off arid winds and protect the fields.这些树能挡住旱风,保护农田。
• There are serious problems of land degradation in some arid zones.在一些干旱地带存在严重的土地退化问题。

4 deteriorating   

恶化，变坏( deteriorate的现在分词 )

参考例句：

• The weather conditions are deteriorating. 天气变得越来越糟。
• I was well aware of the bad morale and the deteriorating factories. 我很清楚，大家情绪低落，各个工厂越搞越坏。

5 curb   

n.场外证券市场，场外交易；vt.制止，抑制

参考例句：

• I could not curb my anger.我按捺不住我的愤怒。
• You must curb your daughter when you are in church.你在教堂时必须管住你的女儿。

6 emissions   

排放物( emission的名词复数 )； 散发物（尤指气体）

参考例句：

• Most scientists accept that climate change is linked to carbon emissions. 大多数科学家都相信气候变化与排放的含碳气体有关。
• Dangerous emissions radiate from plutonium. 危险的辐射物从钚放散出来。

7 fluctuations   

波动，涨落，起伏( fluctuation的名词复数 )

参考例句：

• He showed the price fluctuations in a statistical table. 他用统计表显示价格的波动。
• There were so many unpredictable fluctuations on the Stock Exchange. 股票市场瞬息万变。

8 skeptic   

n.怀疑者，怀疑论者，无神论者

参考例句：

• She is a skeptic about the dangers of global warming.她是全球变暖危险的怀疑论者。
• How am I going to convince this skeptic that she should attention to my research?我将如何使怀疑论者确信她应该关注我的研究呢？

9 viable   

adj.可行的，切实可行的，能活下去的

参考例句：

• The scheme is economically viable.这个计划从经济效益来看是可行的。
• The economy of the country is not viable.这个国家经济是难以维持的。