题目内容
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 oceans’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), oceans have absorbed huge amounts of heat and CO2 in the last forty years.
Fujita explains that "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 oceans only slow the atmospheric warming. Once 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 oceans release this accumulated (积累的) heat is uncertain. And as oceans store heat, fragile underwater ecosystems are struggling.
The most recent scientific report from the Intergovernmental Panel on Climate Change (IPCC) also notes with concern that oceans are 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 oceans.
Currents distributing heat
Another important role 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, oceans’ currents carry oxygen, nutrients and heat throughout the Earth. Oceans distribute 25 percent 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 oceans’ circulation (循环) patterns could throw Europe into a colder period, even as the rest of world experiences warmer temperatures.
1.We can infer from the passage that .
A.oceans cause global warming
B.oceans stop global warming
C.oceans release nutrients and heat
D.ocean ecosystems face more dangers
2.From the passage we can learn that oceans’ currents .
A.produce oxygen and nutrients everywhere
B.absorb 25% to 50% of the energy from the sun
C.distribute heat and nutrients around the globe
D.change oceans’ circulation patterns
3.Which of the following is NOT the result of oceans 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.
4.This passage mainly talks about .
A.the roles of oceans B.global warming
C.ocean currents D.carbon dioxide
1.D
2.C
3.C
4.A
【解析】
试题分析：本文主要讲述了海洋对地球气候的调节作用。
1.小题1】逻辑推理题。从全文特别是第四段的最后一句可知,海洋生态系统面临着诸多威胁,所以选D项。
2.小题2】事实细节题。从最后一段的第二句和第三句可知,海洋的洋流会将营养物质和热量全球性地分布开来,故答案选C项。
3.小题3】正误判断题。从倒数第三段中的"oceans only slow the atmospheric warming"可知,海洋会减缓气候变暖,而不是使大气变得更热,所以选C项。
4.小题4】主旨大意题。文章第一段的第一句就点明了文章主旨,同时结合全文可知,本文主要讲述了海洋对地球气候的调节作用,所以答案选A项。
考点：环保类文章
