PBS高端访谈:气候变化对大堡礁造成致命威胁

 　　JUDY WOODRUFF: The Great Barrier Reef along the coast of Australia is considered one of the greatest natural wonders of the world. It actually consists of more than 2,900 smaller reefs and 900 islands and countless¹ species of fish.

　　But its health and future are very much in doubt.

　　Miles O'Brien has the story for our weekly segment on the Leading Edge of science and technology.

　　MILES O'BRIEN: Half the size of Texas, spanning 1,400 miles, Australia's Great Barrier Reef is the largest living structure on the planet. It is rich in beauty and diversity, but it is dying, as the ocean waters steadily² warm.

　　DAVID WACHENFELD, Great Barrier Reef Marine³ Park Authority: It's a very confronting situation. And I hope the people of the world take this as a call to action to do more about climate change.

　　MILES O'BRIEN: Coral reef ecologist David Wachenfeld is director for reef recovery at the Great Barrier Reef Marine Park Authority. It's the second consecutive⁴ summer of extensive coral destruction, or bleaching⁵, on the reef.

　　DAVID WACHENFELD: We are using aerial surveys and underwater surveys to try and cover that whole enormous area of the Great Barrier Reef to get a handle on the extent and severity of the event. But, certainly, this year is shaping up to be another very bad year, as was last year.

　　MILES O'BRIEN: Last year, two-thirds of the corals in the northern part of the Great Barrier Reef died, the worst die-off in history. As for this year, it is too early to tell. But the outlook is grim, as this is one big piece of an unprecedented⁶ global coral crisis.

　　C. MARK EAKIN, National Oceanic and Atmospheric⁷ Administration Coral Reef Watch: Since June of '14, we have had continuous bleaching somewhere in the world. Globally, over 70 percent of the coral reefs around the globe have been exposed to the high temperatures that cause bleaching.

　　MILES O'BRIEN: Coral reef ecologist Mark Eakin is the coordinator⁸ for the National Oceanic and Atmospheric Administration's Coral Reef Watch.

　　He relies on data from scientific satellites operated by NOAA, the Europeans, and the Japanese that measure ocean water temperature. He, along with David Wachenfeld, is co-author of a new study published in the journal "Nature" documenting the link between warm waters and dying coral in the Great Barrier Reef.

　　C. MARK EAKIN: What we did here at Coral Reef Watch was to provide the satellite data that gives the information on the areas where the high temperatures occurred.

　　So, there are charts in there showing where the bleaching was worst and where the temperatures were highest for the longest time, and the correlation⁹ between that heat stress and where the bleaching occurred was very high.

　　气候变化对大堡礁造成致命威胁

　　MILES O'BRIEN: Coral reefs are the rain forests of the sea, brimming with mind-boggling diversity that is still not fully¹⁰ explored.

　　JENNIFER SMITH, Scripps Institution of Oceanography, UCSD: Despite the fact that coral reefs occupy a very small footprint of the overall Earth's surface, less than 0.1 percent, an area about the size of the country of France, they're home to more species of marine organisms than any other marine ecosystem¹¹ on the planet.

　　MILES O'BRIEN: Jen Smith is associate professor in marine biology at the Scripps Institution of Oceanography at the University of California, San Diego.

　　We met at Scripps' Birch Aquarium¹², home to some spectacular displays of reef ecosystems¹³ to nurture¹⁴ curious minds and, behind the scenes, an extensive nursery to nurture the coral itself.

　　Most corals are nourished through a symbiotic¹⁵ relationship with algae¹⁶, that convert sunlight into energy, which the corals tap into.

　　JENNIFER SMITH: So, it's like having a garden growing in your stomach where 90 percent of your daily nutrition comes directly from that garden in your stomach.

　　MILES O'BRIEN: The pigments¹⁷ in the algae are the source of the vivid rainbow of colors in a healthy coral reef. But the algae are very temperature-sensitive. A few degrees warmer than normal, and their photosynthesis¹⁸ is enhanced. That may sound good, but the unfortunate byproduct is a toxin¹⁹.

　　So, the coral is forced to spit out its food source, revealing its white color, thus the term bleaching. Jen Smith showed me Birch's display of an unhealthy bleached²⁰ coral reef.

　　JENNIFER SMITH: As long as you still see white skeleton, that's usually an indication that the coral is still alive, because, as soon as the tissue starts dying, your seaweed will start settling on that skeleton and start growing over it.

　　So, within a matter of a few weeks or even a month during a bleaching event, you will have an idea of whether that coral is dead and getting overgrown by seaweed, or whether it's on its way to recovery.

　　MILES O'BRIEN: The sustained global bleaching event is not giving corals a chance to recover. Many coral reefs are further stressed by other types of human activity: runoff from sewage, agriculture, and overfishing.

　　But scientists say the current bleaching is happening whether those local factors are present or not. It is clear warming water is the culprit, and reducing our use of fossil fuels is the only solution.

　　Scientists say the world must adhere to obligations to do just that made by 195 nations in Paris in 2015.

　　C. MARK EAKIN: This is really the only thing that's going to deal with this global coral bleaching problem. Even if we do, though, we're going to lose a lot of coral reefs.

　　MILES O'BRIEN: But the Trump²¹ administration is filled with climate change skeptics pushing to roll back Obama-era regulations aimed at reducing greenhouse gases.

　　So, what if we do nothing to slow climate change?

　　JENNIFER SMITH: Corals reefs as we know them will not exist in the next 10, 20, 30 years. We could single-handedly be responsible for the extinction²² of an entire ecosystem.

　　MILES O'BRIEN: Coral reefs are more than spectacular, vivid examples of nature's beauty. The fish they harbor are also a food source for a half-billion people, and natural barriers against storms and floods.

　　But, before too long, they may only exist behind glass.

　　Miles O'Brien, the PBS NewsHour, La Jolla, California.

　　JUDY WOODRUFF: Clearly, they are a global treasure. Let's hope more attention is paid to how to save them.

1 countless   

adj.无数的，多得不计其数的

参考例句：

• In the war countless innocent people lost their lives.在这场战争中无数无辜的人丧失了性命。
• I've told you countless times.我已经告诉你无数遍了。

2 steadily   

adv.稳定地；不变地；持续地

参考例句：

• The scope of man's use of natural resources will steadily grow.人类利用自然资源的广度将日益扩大。
• Our educational reform was steadily led onto the correct path.我们的教学改革慢慢上轨道了。

3 marine   

adj.海的；海生的；航海的；海事的；n.水兵

参考例句：

• Marine creatures are those which live in the sea. 海洋生物是生存在海里的生物。
• When the war broke out,he volunteered for the Marine Corps.战争爆发时，他自愿参加了海军陆战队。

4 consecutive   

adj.连续的，联贯的，始终一贯的

参考例句：

• It has rained for four consecutive days.已连续下了四天雨。
• The policy of our Party is consecutive.我党的政策始终如一。

5 bleaching   

漂白法，漂白

参考例句：

• Moderately weathered rock showed more intense bleaching and fissuring in the feldspars. 中等风化岩石则是指长石有更为强烈的变白现象和裂纹现象。
• Bleaching effects are very strong and show on air photos. 退色效应非常强烈，并且反映在航空象片上。

6 unprecedented   

adj.无前例的，新奇的

参考例句：

• The air crash caused an unprecedented number of deaths.这次空难的死亡人数是空前的。
• A flood of this sort is really unprecedented.这样大的洪水真是十年九不遇。

7 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。

8 coordinator   

n.协调人

参考例句：

• The UN Office for the Coordination of Humanitarian Affairs, headed by the Emergency Relief Coordinator, coordinates all UN emergency relief. 联合国人道主义事务协调厅在紧急救济协调员领导下，负责协调联合国的所有紧急救济工作。
• How am I supposed to find the client-relations coordinator? 我怎么才能找到客户关系协调员的办公室？

9 correlation   

n.相互关系，相关，关连

参考例句：

• The second group of measurements had a high correlation with the first.第二组测量数据与第一组高度相关。
• A high correlation exists in America between education and economic position.教育和经济地位在美国有极密切的关系。

10 fully   

adv.完全地，全部地，彻底地；充分地

参考例句：

• The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气，然后全部呼出。
• They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。

11 ecosystem   

n.生态系统

参考例句：

• This destroyed the ecosystem of the island.这样破坏了岛上的生态系统。
• We all have an interest in maintaining the integrity of the ecosystem.维持生态系统的完整是我们共同的利益。

12 aquarium   

n.水族馆，养鱼池，玻璃缸

参考例句：

• The first time I saw seals was in an aquarium.我第一次看见海豹是在水族馆里。
• I'm going to the aquarium with my parents this Sunday.这个星期天，我要和父母一起到水族馆去。

13 ecosystems   

n.生态系统( ecosystem的名词复数 )

参考例句：

• There are highly sensitive and delicately balanced ecosystems in the forest. 森林里有高度敏感、灵敏平衡的各种生态系统。 来自《简明英汉词典》
• Madagascar's ecosystems range from rainforest to semi-desert. 马达加斯加生态系统类型多样，从雨林到半荒漠等不一而足。 来自辞典例句

14 nurture   

n.养育，照顾，教育；滋养，营养品；vt.养育，给与营养物，教养，扶持

参考例句：

• The tree grows well in his nurture.在他的培育下这棵树长得很好。
• The two sisters had received very different nurture.这俩个姊妹接受过极不同的教育。

15 symbiotic   

adj.共栖的，共生的

参考例句：

• Racing has always had a symbiotic relationship with betting.赛马总是与赌博相挂钩。
• Engineering completely new symbiotic relationship is obviously not an imminent possibility.筹划完全新的共生关系显然是可能性不大。

16 algae   

n.水藻，海藻

参考例句：

• Most algae live in water.多数藻类生长在水中。
• Algae grow and spread quickly in the lake.湖中水藻滋蔓。

17 pigments   

n.（粉状）颜料( pigment的名词复数 )；天然色素

参考例句：

• The Romans used natural pigments on their fabrics and walls. 古罗马人在织物和墙壁上使用天然颜料。 来自辞典例句
• The original white lead pigments have oxidized and turned black. 最初的白色铅质颜料氧化后变成了黑色。 来自辞典例句

18 photosynthesis   

n.光合作用

参考例句：

• In apple trees photosynthesis occurs almost exclusively in the leaves.苹果树的光合作用几乎只发生在叶内。
• Chloroplasts are the structures in which photosynthesis happens.叶绿体就是光合作用发生的地方。

19 toxin   

n.毒素，毒质

参考例句：

• Experts have linked this condition to a build-up of toxins in the body.专家已把这一病症与体内毒素的积累联系起来。
• Tests showed increased levels of toxin in shellfish.检验表明水生有壳动物的毒素水平提高了。

20 bleached   

漂白的，晒白的，颜色变浅的

参考例句：

• His hair was bleached by the sun . 他的头发被太阳晒得发白。
• The sun has bleached her yellow skirt. 阳光把她的黄裙子晒得褪色了。

21 trump   

n.王牌，法宝；v.打出王牌，吹喇叭

参考例句：

• He was never able to trump up the courage to have a showdown.他始终鼓不起勇气摊牌。
• The coach saved his star player for a trump card.教练保留他的明星选手，作为他的王牌。

22 extinction   

n.熄灭，消亡，消灭，灭绝，绝种

参考例句：

• The plant is now in danger of extinction.这种植物现在有绝种的危险。
• The island's way of life is doomed to extinction.这个岛上的生活方式注定要消失。