Lee Hotz: 南极时间机器

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http://dotsub.com/view/9dd000c5-e9c8-4d00-816e-ea8b73916ec4
Lee Hotz: 南极时间机器
请与我一起来到世界的最底部 南极洲， 最高，最为干燥，风力最为强劲的区域 并且也是地球上最为寒冷的地方-- 比撒哈拉沙漠更为干燥 并且在部分区域比火星还要寒冷。 南极洲的冰块 在阳光的照耀下非常刺眼， 它甚至可让你失明。 早期的探险者把可卡因涂在眼睛里面 以抑制那难以忍受的疼痛。 南极洲庞大冰块的大部分重量 隐藏于海平面之下。 同时，南极洲的冰块 还是记录气候变化的日历。 它记录了从冰河时代开始至今 每年温室气体和温度 的增长和下降。 地球上没有任何一个其它地方可以 为我们提供如此良好的历史记录。 在这里，科学家们正在钻探着 我们星球过去的历史 以寻找到通向 未来气候变化的线索。
在刚过去的一月里， 我来到了名为南极洲西部冰原区， 一个大约位于距离南极点600英里处的区域。 很多人说这里是探索星球的最佳地点， 可以探索研究气候变化的历史。 这里约有45名来自威斯康辛大学， 内华达的沙漠研究中心和其它机构的科学家， 他们正致力于回答关于 全球变暖的关键疑问。 在温室气体程度 和星球温度之间 到底存在什么样的关系？ 这是非常紧迫的工作．我们知道温度在不断上升。 刚过去的五月是有记录以来最温暖的五月。 并且我们也知道温室气体在不断增加。 但是我们还不了解的是 这些变化将会给 自然气候带来 怎样精确即时的影响-- 比如暴风，海洋流， 沉淀率，风云信息等， 这些因素影响着 亿万人民健康和生活水平。
他们整个研究所，包括每个齿轮 都是从位于美国在南极洲海岸 设立的供应基地 ---麦克默多站 横渡搬运885公里到此。 虽然南极洲西部冰原区仅是 位于大雪中的一圈帐篷， 在暴风雪中，帐篷将会被钢丝绳连接在一起， 这样人们可以感觉到 从最近的冰屋 到最近的外屋而更有安全感。 在这里暴风雪非常惊人， 设施曾经几乎在一瞬间被毁。 确实，研究学者们之所以挑选这里 是因为在这里冰和雪的积累速度 比南极洲的其它任何地方都快十倍。 每天他们都得把自己从雪中挖出来。 这可是一条很奇异 并且很寒冷的通行路。
(笑声)
但是在这表面之下， 他们围绕着一台八百万美元的钻机正进行着积极的工业 探索。 每隔一段时间这台钻机就像活检针检查一样 深入上千英尺的冰层中 抽取出气体的精华 和同位体以应用于分析。 每天十次，他们提取 十英尺长的压缩冰晶柱 其中包含了 在经过了上千年的历史更迭之后雪层下 未经污染的气体和轨迹化学物。 它就像一台时间机器。 在今年早些时候的探索高峰期时， 研究者们把钻头再往冰层中 多钻探了一百多英尺， 从而了解了 比之前更早的365年的历史。 他们定期地 除去冰柱 就像看守员从钻头的外壳上 除掉老化的外壳。 他们对其进行检测以检查， 是否有裂缝，有钻头破损裂开等。
更为重要的是， 他们为位于美国和欧洲的 27个独立实验室提供样品以 进行检测和分析， 他们可以检测到与气候相关的 四十种不同的轨迹化合物， 有的含量仅为百万的四次乘方（一千万亿）之一。 是的，我是指这个百万的四次乘方（一千万亿）。 他们将冰柱分割成为三英尺的小块 为离钻头点约8000英里外的这些实验室中提供更为方便的 操作和冰柱搬运 。 每个冰柱都是 时间的真实记录。
这些冰块大约 15800年前形成雪， 那个时候我们祖先还在玩弄着涂料 并在思考着关于 字母的新技术。 在极光的浸沐下 被切成截面的 这古代的冰块 展示出了某种马塞克色彩， 每一个都展现出在冰块中的深度 如何影响了这种材料 在不同深度时 压力可达到每平方英寸一吨。 每年都下雪， 从而钻探进入最新鲜的雪层， 今天可以看到这个过程是如何进行的。 在未经开采的雪层下， 太阳光所造成的背光 映射出冬雪和夏雪的条纹， 一层接着一层。 每次暴风雪席卷着大气， 冲洗掉灰尘，煤烟， 踪迹化学物， 并将其沉淀于雪层上 年复一年， 成千上万年， 形成了 在这里 超过11000英尺厚的雪层中的这种时代周期表。 从中我们可以检测到种类繁多的物质。 我们可以找到 来自世界沙漠的钙， 来自遥远野火的煤烟， 来自太平洋雨季的指示物甲烷， 它们都从温暖的地方 来到这遥远寒冷的地方。
最为重要的是， 这些冰柱和雪层 可捕捉气体。 每个冰柱大约含有10%的古代气体 是关于温室气体的 原始纯净信息---二氧化碳， 甲烷和氧化氮-- 从雪形成且落下的那天开始 便未曾发生变化。 这便是他们的调查对象。 但是难道我们不是已经知道了 关于温室气体所需要知道的信息吗？ 为什么我们还需要进一步研究它呢？ 难道我们不是已经知道它如何影响气温吗？ 难道我们不是已经知道了变化的气候 所带来的结果将如何影响我们的文明社会吗？ 事实是，我们仅仅知道其大致轮廓， 并非是完全彻底理解， 甚至我们不能完好地对其进行修复。 事实上，我们还冒着把事情弄得更糟的风险。
20世纪最为成功的 国际环境保护条例， 蒙特利尔法案 旨在联合世界各国以保护我们的星球免于 受到当时在空调，电冰箱和其它冷却设备中 广泛使用中的 臭氧破坏化学物的影响。 我们禁止了这些化学物 而使用了其它我们未知的物质 进行了替换, 而每一个新物质分子 都比二氧化碳 更为可能成为 传热的温室气体。
这样的过程需要 特别的谨慎预防。 科学家们必须确保 冰层未受到污染。 并且在这长达8000英里的旅途中， 他们必须得确保冰不会融化。 想象一下夹着雪球穿过热带地区吧。 他们必须得确保 冰不会变得 高于零下20度， 否则其中的关键气体就会挥发。 因此在地球最为寒冷的地区 他们就像在电冰箱中工作一样。 当他们操作冰雪时，事实上 他们还预留一双置于烤箱中的手套， 因为当他们的工作手套冻结时， 他们的手指变得僵硬， 他们可以更换上预备手套来暖手。 他们与时间和温差进行着斗争。
目前为止，他们已经堆积了 大约4500英尺的冰雪， 这些冰雪都将会被运回美国。 在刚过去的季节中， 他们将这些冰雪搬运出冰层 以等待空中运送飞机。 109号空军护卫队 将最近的冰雪运到 南极洲海岸， 在这里将会被搬上货轮， 穿过热带以来到加利福尼亚， 卸货并装运上货车， 穿过沙漠 抵达位于科罗拉多州丹佛的国家冰雪中心研究室， 在那里，正于我们所说的那样， 科学家将材料切成片 以制成样品用于分析， 再将样品分送到 全国各地和欧洲 的实验室里。
南极洲是星球上 最后的--- 不断扩张的世界中 唯一的盲点。 早期的探险家们 航海来到了地图的这边缘地带南极洲， 并且他们找到某个 似乎传统的时间和温度规则 都不再有效的区域。 在这里，冰雪就如同活生生的存在。 暴风雪不断地侵蚀着南极洲， 赐于它独特的魅力。 这是一种有魅力的体验。 而这正是我们所需要的嗓音。
谢谢你们。
(掌声)


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Lee Hotz: Inside an Antarctic time machine
Come with me to the bottom of the world, Antarctica, the highest, driest, windiest, and yes, coldest region on Earth -- more arid than the Sahara and, in parts, colder than Mars. The ice of Antarctica glows with a light so dazzling, it blinds the unprotected eye. Early explorers rubbed cocaine in their eyes to kill the pain of it. The weight of the ice is such that the entire continent sags below sea level, beneath its weight. Yet, the ice of Antarctica is a calendar of climate change. It records the annual rise and fall of greenhouse gases and temperatures going back before the onset of the last ice ages. Nowhere on Earth offers us such a perfect record. And here, scientists are drilling into the past of our planet to find clues to the future of climate change.

This past January, I traveled to a place called WAIS Divide, about 600 miles from the South Pole. It is the best place on the planet, many say, to study the history of climate change. There, about 45 scientists from the University of Wisconsin, the Desert Research Institute in Nevada and others have been working to answer an essential question about global warming. What is the exact relationship between levels of greenhouse gases and planetary temperatures? It's urgent work. We know that temperatures are rising. This past May was the warmest worldwide on record. And we know that levels of greenhouse gases are rising too. What we don't know is the exact, precise, immediate impact of these changes on natural climate patterns -- winds, ocean currents, precipitation rates, cloud formation, things that bear on the health and well-being of billions of people.

Their entire camp, every item of gear, was ferried 885 miles from McMurdo Station, the main U.S. supply base on the coast of Antarctica. WAIS Divide itself though, is a circle of tents in the snow. In blizzard winds, the crew sling ropes between the tents so that people can feel their way safely to the nearest ice house and to the nearest outhouse. It snows so heavily there, the installation was almost immediately buried. Indeed, the researchers picked this site because ice and snow accumulates here 10 times faster than anywhere else in Antarctica. They have to dig themselves out every day. It makes for an exotic and chilly commute.

(Laughter)

But under the surface, is a hive of industrial activity centered around an eight-million-dollar drill assembly. Periodically, this drill, like a biopsy needle, plunges thousands of feet deep into the ice to extract a marrow of gases and isotopes for analysis. 10 times a day, they extract the 10-foot long cylinder of compressed ice crystals that contain the unsullied air and trace chemicals laid down by snow, season after season for thousands of years. It's really a time machine. At the peak of activity earlier this year, the researchers lowered the drill an extra hundred feet deeper into the ice every day and another 365 years deeper into the past. Periodically, they remove a cylinder of ice, like gamekeepers popping a spent shotgun shell from the barrel of a drill. They inspect it, they check it for cracks, for drill damage, for spalls, for chips.

More importantly, they prepare it for inspection and analysis by 27 independent laboratories in the United States and Europe, who will examine it for 40 different trace chemicals related to climate, some in parts per quadrillion. Yes, I said that with a Q, quadrillion. They cut the cylinders up into three-foot sections for easier handling and shipment back to these labs, some 8,000 miles from the drill site. Each cylinder is a parfait of time.

This ice formed as snow 15,800 years ago, when our ancestors were daubing themselves with paint and considering the radical new technology of the alphabet. Bathed in polarized light and cut in cross-section, this ancient ice reveals itself as a mosaic of colors, each one showing how conditions at depth in the ice have affected this material at depths where pressures can reach a ton per square inch. Every year, it begins with a snowflake, and by digging into fresh snow, we can see how this process is ongoing today. This wall of undisturbed snow, back-lit by sunlight, shows the striations of winter and summer snow, layer upon layer. Each storm scours the atmosphere, washing out dust, soot, trace chemicals, and depositing them on the snow pack year after year, millennia after millennia, creating a kind of periodic table of elements that at this point is more than 11,000 ft. thick. From this, we can detect an extraordinary number of things. We can see the calcium from the world's deserts, soot from distant wildfires, methane as an indicator of a Pacific monsoon, all wafted on winds from warmer latitudes to this remote and very cold place.

Most importantly, these cylinders and this snow trap air. Each cylinder is about 10 percent ancient air, a pristine time capsule of greenhouse gases -- carbon dioxide, methane, nitrous oxide -- all unchanged from the day that snow formed and first fell. And this is the object of their scrutiny. But don't we already know what we need to know about greenhouse gases? Why do we need to study this anymore? Don't we already know how they affect temperatures? Don't we already know the consequenses of a changing climate on our settled civilization? The truth is, we only know the outlines, and what we don't completely understand, we can't properly fix. Indeed, we run the risk of making things worse.

Consider, the single most successful international environmental effort of the 20th century, the Montreal Protocol, in which the nations of Earth banded together to protect the planet from the harmful effects of ozone-destroying chemicals used at that time in air conditioners, refrigerators and other cooling devices. We banned those chemicals, and we replaced them, unknowingly, with other substances that, molecule per molecule, are a hundred times more potent as heat-trapping, greenhouse gases than carbon dioxide.

This process requires extraordinary precautions. The scientists must insure that the ice is not contaminated. Moreover, in this 8,000-mile journey, they have to insure this ice doesn't melt. Imagine juggling a snowball across the tropics. They have to, in fact, make sure this ice never gets warmer than about 20 degrees below zero, otherwise, the key gases inside it will dissipate. So, in the coldest place on Earth, they work inside a refrigerator. As they handle the ice, in fact, they keep an extra pair of gloves warming in an oven, so that, when their work gloves freeze and their fingers stiffen, they can don a fresh pair. They work against the clock and against the thermometer.

So far, they've packed up about 4,500 ft. of ice cores for shipment back to the United States. This past season, They manhandled them across the ice to waiting aircraft. The 109th Air National Guard flew the most recent shipment of ice back to the coast of Antarctica, where it was boarded onto a freighter, shipped across the tropics to California, unloaded, put on a truck, driven across the desert to the National Ice Core Laboratory in Denver, Colorado, where, as we speak, scientists are now slicing this material up for samples, for analysis, to be distributed to the laboratories around the country and in Europe.

Antarctica was this planet's last empty quarter -- the blind spot in our expanding vision of the world. Early explorers sailed off the edge of the map, and they found a place where the normal rules of time and temperature seem suspended. Here, the ice seems a living presence. the wind that rubs against it gives it voice. It is a voice of experience. It is a voice we should heed.

Thank you.

(Applause)