VOA慢速英语2021--科学家担心冰川正在消失

（单词翻译）

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