Scientistshavelongunderstoodthekeyrolethatoceansplayinr...

问题详情：

Scientists have long understood the key role that oceans play in regulating the Earth’s climate. Oceans cover 70 percent of the globe and store a thousand times more heat than the atmosphere does. What’s newer is the understanding of how this key component of our climate system responds to global warming.

A brake on global warming—for now

One of the ocean’s most important climate functions is absorbing heat and carbon dioxide (CO2), one of the gases that cause global warming. Acting as a heat sponge (海绵), the oceans have absorbed huge amounts of heat and CO2 in the last forty years.

Fujita explains that “the oceans are saving us from faster climate change—they are a big flywheel that delays rapid overheating of the earth, putting a brake on the climate system.”

“That’s the good news,” he adds. “The bad news is that the oceans only slow the atmospheric warming. Once the oceans come to balance with a greenhouse-gas warmed earth, the extreme heat will remain in the atmosphere and things will get much hotter.” But where and how the oceans release this accumulated (积累) heat is uncertain. And as the ocean stores heat, fragile underwater ecosystems are struggling.

The most recent scientific report from the Intergovernmental Panel on Climate Change (IPCC) also notes with concern that the ocean is acidifying because of increased absorption of atmospheric CO2, and thus causing a threat for shell-forming species. Sharp increases in carbon dioxide levels will cause further acidification of the ocean.

Currents distributing heat

Another important role the oceans play is that of distributor. Oceans deliver heat and life-sustaining nutrients around the globe. Just as blood vessels bring oxygen and nutrients to cells in the human body, the ocean’s currents carry oxygen, nutrients and heat throughout the Earth. The ocean distributes 25 to 50 percent of the energy the planet receives from the sun. For example, the Gulf Stream carries heat across the Atlantic. This warm current gives northwestern Europe a milder climate than it would normally have so far north. A change to the ocean’s circulation (循环) patterns could throw Europe into a colder period, even as the rest of world experiences warmer temperatures.

12. We can infer from the passage that _____.

A. the oceans cause global warming          B. the oceans stop global warming

C. the oceans release nutrients and heat      D. the ocean ecosystems face more dangers

13. From the passage we can learn that the ocean’s currents _____.

A. produce oxygen and nutrients everywhere B. absorb 25~50% of the energy from the sun

C. distribute heat and nutrients around     D. change the ocean’s circulation patterns

14. Which of the following is NOT the result of the ocean absorbing heat and carbon dioxide?

A. It causes further acidification.         B. It affects shell-forming species.

C. It makes the atmosphere hotter.          D. It regulates the Earth’s climate.

15. This passage mainly talks about ______.

A. the roles of oceans  B. global warming  C. ocean currents     D. carbon dioxide

【回答】

DCCA

知识点：科普环保类阅读

题型：阅读理解