VOA慢速英语2021--科学家担心冰川正在消失

Scientists Concerned About Shrinking Glaciers²

Scientists are racing³ to collect ice cores as the earth's warming melts large areas of ice known as glaciers and ice sheets. Some scientists say there is very little time left. And, in some cases, it is already too late.

Late last year, chemist Margit Schwikowski and a team of international scientists attempted to gather ice cores from the Grand Combin glacier¹.

In 2018, they had visited the area and took a small test core. The core was in good shape, said Schwikowski, head of a chemistry group at the Paul Scherrer Institute in Villigen, Switzerland.

The core had well-preserved atmospheric⁴ gases and chemical evidence of past climates.

But, in the two years it took for the scientists to return with a full drilling set-up, some of the information that had been trapped in the ice had disappeared.

The sudden change "tells us exactly how sensitive these glaciers are," said Schwikowski. "We were just two years too late."

The mission on Grand Combin shows the major difficulty scientists face today in collecting ice cores.

Some glaciers are disappearing faster than expected, leading scientists to do missions sooner, rethink where to target next, and plan about increased storage.

The United Nations says almost all of the world's glaciers are becoming smaller. In its most complete climate report to date, published in August, the UN said that human actions are "very likely the main driver of the near-universal retreat of glaciers globally since the 1990s."

About 10 percent of the land area on earth is currently covered with glacial ice, says the National Snow and Ice Data Center in Boulder⁵, Colorado.

If a glacier is melting, it means it also is not storing atmospheric gases from today for scientists to study in the future.

Beyond gases, scientists say they may be able to use ice cores to study the DNA⁶ of ancient bacteria and viruses that could come back as the world warms. Frozen insects and plant material could also reveal histories of the world's forests.

Another team of scientists, whose findings were published in July in Microbiome, found viruses nearly 15,000 years old in two ice core samples taken from the Tibetan Plateau in China. The findings identified genetic⁷ codes for 33 viruses. At least 28 of them were new to scientists.

That team of scientists included U.S.-based ice core experts Lonnie Thompson and Ellen Mosley-Thompson, who are husband and wife.

Lonnie Thompson said he plans to increase his ice core storage facilities at Ohio State University.

Some of the cores Thompson and his team have collected are the only remaining ice from some glaciers.

Thompson used the term archive – meaning a place where records or materials are kept - to talk about ice.

"Ice has a wonderful archive of not only the climate, but also the forcings of climate," the major causes of climate change, Thompson said. "Those histories are at risk as the earth warms and the glaciers retreat."

Words in This Story

core – n. technical : a part that has been removed from a material for scientific study

well-preserved – adj. kept in good condition over a long period of time

code – n. a set of letters, numbers, symbols, etc., that identifies or gives information about something or someone

sensitive – adj. changing in response to something; easily affected by something in a way that is not pleasant or good

1 glacier   

n.冰川，冰河

参考例句：

• The glacier calved a large iceberg.冰河崩解而形成一个大冰山。
• The upper surface of glacier is riven by crevasses.冰川的上表面已裂成冰隙。

2 glaciers   

冰河，冰川( glacier的名词复数 )

参考例句：

• Glaciers gouged out valleys from the hills. 冰川把丘陵地带冲出一条条山谷。
• It has ice and snow glaciers, rainforests and beautiful mountains. 既有冰川，又有雨林和秀丽的山峰。 来自英语晨读30分（高一）

3 racing   

n.竞赛，赛马；adj.竞赛用的，赛马用的

参考例句：

• I was watching the racing on television last night.昨晚我在电视上看赛马。
• The two racing drivers fenced for a chance to gain the lead.两个赛车手伺机竞相领先。

4 atmospheric   

adj.大气的，空气的；大气层的；大气所引起的

参考例句：

• Sea surface temperatures and atmospheric circulation are strongly coupled.海洋表面温度与大气环流是密切相关的。
• Clouds return radiant energy to the surface primarily via the atmospheric window.云主要通过大气窗区向地表辐射能量。

5 boulder   

n.巨砾；卵石，圆石

参考例句：

• We all heaved together and removed the boulder.大家一齐用劲，把大石头搬开了。
• He stepped clear of the boulder.他从大石头后面走了出来。

6 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

7 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。