您现在的位置: VOA >> VOA双语新闻 >> 双语新闻 >> 正文

阿拉斯加冻土大消融时代来临

更新时间:2017/11/8 19:17:58 来源:本站原创 作者:佚名

The great thaw of america's north is coming
阿拉斯加冻土大消融时代来临

Vladimir Romanovsky walks through the dense black spruce forest with ease. Not once does he stop or slow down to balance himself on the cushy moss beneath his feet insulating the permafrost.

弗拉基米尔·罗曼诺夫斯基(Vladimir Romanovsky)轻松稳步地穿过茂密的黑云杉树林,脚下踩着的是隔绝着冻土层的松软苔藓。

It’s a warm day in July, and the scientist is looking for a box that he and his team have installed on the ground. It’s hidden nearly six miles (10km) north of the Geophysical Institute at the University of Alaska in Fairbanks, where he’s a professor of geophysics and heads the Permafrost Laboratory.

这是七月里温暖的一天,这位科学家正在寻找一个他和他的小组安放在地下的盒子。这个盒子隐藏在阿拉斯加大学费尔班克斯分校(University of Alaska Fairbanks)地球物理研究所(Geophysical Institute)以北近六英里(10公里)的某处,而罗曼诺夫斯基则是该研究所的地球物理学教授和永冻土实验室(Permafrost Laboratory)主任。

The box, which is covered by tree branches, contains a data collector connected to a thermometer installed below ground for measuring permafrost temperature at different depths. Permafrost is any earth material that remains at or below 0C (32F) for at least two consecutive years.

这个由树枝覆盖的盒子里装有一个与安装在地下的温度计相连的数据采集器,温度计用于测量不同深度的永冻土温度。永冻土是至少连续两年维持在0摄氏度(32华氏度)或低于0摄氏度的土壤。

Romanovsky connects his laptop to the data collector to transfer the temperature data for this location – called Goldstream III – which he will later add to an online database accessible to both scientists and interested individuals.

罗曼诺夫斯基将他的笔记本电脑与数据采集器相连,并将这一称为金溪三号(Goldstream III )的地点的温度数据上传,稍后他会将这些数据添加到一个在线数据库,供科学家和感兴趣的个人访问。

“Permafrost is defined on the basis of temperature, the parameter that characterises its stability,” Romanovsky says.

"永冻土层的定义基于温度,这项参数直接反映了其稳定性,"罗曼诺夫斯基说。

When the temperature of permafrost is below 0C (32F), for example -6C (21F), it is considered stable and will take a long time to thaw or to change. If it's close to 0C, however, it's considered vulnerable.

当温度低于摄氏零度(或32华氏度),例如摄氏零下6度(或21华氏度),冻土被认为是稳定的,需要很长时间才能解冻或发生改变。然而如果温度接近0摄氏度,这时冻土则被认为是脆弱的。

Every summer the portion of soil overlaying the permafrost, called the active layer, thaws, before refreezing the following winter. At Goldstream III, on this July day, the summer thaw currently ends at 50cm depth.

每年夏天,称为活性层的永冻土层之上的那部分土壤会解冻,活性层在接下来的冬天会再次冻结。在七月的这一天,金溪三号这个地点的夏季解冻深度达到50厘米。

As the Earth warms and summer temperatures climb, the thaw is deepening and expanding, causing the permafrost underneath to become less stable.

随着地球变暖和夏季气温上升,解冻深度正在加深,解冻范围在扩大,导致下面的永久冻土变得不那么稳定。

The consequences, if this thawing continues, will be profound, for Alaska – and for the world. Nearly 90% of the state is covered in permafrost, which means entire villages will need to be relocated, as the foundations of buildings and roads crumble. And if this frozen cache releases the millennia of accumulated carbon it has locked within, it could accelerate the warming of our planet – far beyond our ability to control it.

如果这种融化继续下去,对阿拉斯加乃至全世界而言,其后果都将是深远的。该州90%的面积被永久冻土覆盖,这意味着由于建筑物和道路的地基崩塌,整个整个的村庄需要搬迁。如果冻土层释放几千年来封存并积聚其内的碳物质,这将加速我们星球的变暖速度——远远超出我们控制的能力。

A vulnerable state

脆弱的状态

As permafrost thaws, houses, roads, airports and other infrastructure built on the frozen ground can crack and even collapse.

随着永久冻土融解,建在冻土土层之上的房屋、道路、机场和其他基础设施将开裂甚至倒塌。

“We are seeing some increased maintenance on existing roads over permafrost,” says Jeff Currey, materials engineer for Northern Region of the Alaska Department of Transportation Public Facilities. “One of our maintenance superintendents recently told me his folks are having to patch settling areas on the highways he's responsible for more frequently than they were 10 or 20 years ago.”

"我们注意到,修建在永冻土层上的道路的维护工作在增加,"阿拉斯加州交通运输部公共设施处(Alaska Department of Transportation Public Facilities)北部地区(Northern Region)的材料工程师杰夫·库里(Jeff Currey)说,"我们的一个维修主管最近告诉我,相比10年或20年前,他们对高速公路区域内的地面沉降进行的修补更为频繁。"

Similarly, infrastructure built underground – such as those for utilities – is suffering as temperatures rise.

同样的,修建在地下的基础设施(比如公用事业设施)也因气温上升而受到影响。

“In Point Lay – on the coast in northwest Alaska – for instance, they're having all sorts of trouble with their water and sewer lines buried in permafrost soil,” says William Schnabel, director of the Water & Environmental Research Center at the University of Alaska Fairbanks. “The permafrost soil has thawed and we get water and line breaks because the ground shifts.”

"例如在阿拉斯加西北海岸的波因特莱(Point Lay),那里建在永久冻土中的自来水管线和下水道遇到了各式各样的麻烦,"阿拉斯加大学费尔班克斯分校的水与环境研究中心(Water & Environmental Research Center )主任威廉·施纳贝尔(William Schnabel)说:"永久冻土的融化,导致地层移位,使得输水管道破裂。"

The concern is even more pronounced for those living in rural areas who don't have enough funds to combat the effects of thawing permafrost. For those residents it's not just about collapsing buildings, which is common now, but also water supply.

对于那些没有足够资金应对冻土融化影响的农村居民来说,这种担忧更为明显。对于那些居民来说,这不仅仅是目前颇为常见的建筑物倒塌问题,也包括供水。

Often as permafrost thaws on the side of a lake that a village might use as water supply, there’s a breach and a lateral drain occurs. “It usually requires pretty expensive infrastructure to take water from a lake, bring it to a village and store it and all the components of this infrastructure are vulnerable to thawing permafrost,” Romanovsky says.

当被某个村庄当作水源地的湖岸一侧发生永冻土融化,通常会出现裂口和侧漏。"从湖中取水、引到村里并存储起来通常需要相当昂贵的基础设施,而这一基础设施的所有部件对于永冻土解冻而言都显得非常脆弱,"罗曼诺夫斯基说。

If a village depends on an affected lake for water, the community members would have to move their infrastructure and sometimes their entire village to another lake, which can be very costly.

如果一个村庄依赖供水的湖泊受到影响,那么社区成员就不得不把他们的基础设施,有时甚至整个村庄搬到另一个湖泊附近,这可能是非常昂贵的举措。

According to research conducted by US Geological Survey, villages like Kivalina in north-west Alaska will have to move within the next 10 years, Romanovsky explains. “But estimates show cost of moving is about $200m (£150m) per village of 300 people.”

据美国地质调查局(US Geological Survey)进行的研究,在阿拉斯加西北部的那些村庄,例如基瓦利纳村(Kivalina),不得不在未来10年迁走,罗曼诺夫斯基解释说,"但是估算显示,一个300人的村子的搬家成本约为2亿美元(1.5亿英镑)。"

Those kinds of sums are only possible with federal government funding – but there are also no guarantees that a new location wouldn’t be affected eventually too.

只有联邦政府的资助才可能负担如此大的费用,而且谁也保证不了新的定居点最终不会受到影响。

“I think by now there are 70 villages who really have to move because of thawing permafrost,” Romanovsky says. “But moving villages to another location on permafrost is very difficult to guarantee for 30 years or so and the federal government doesn't want to pay for something they have to pay for again.”

"我认为现在有70个村子的人不得不因为永冻土融化而迁走,"罗曼诺夫斯基说,"但是将村庄迁移到永冻土带的另一个地点很难保证30年内不出问题,如果有出问题,联邦政府可能不愿意买单。"

It’s possible that building Alaskan settlements on permafrost may also be making the problem worse. “When you think about water and sewers you have to keep those above freezing and when you have permafrost you have to keep that below freezing,” Schnabel says. “So you're running relatively warm water through the permafrost and there's going to be some heat dissipation in there.”

在永久冻土带修建阿拉斯加人定居点的活动也可能使问题更加恶化。"当你想到供水和下水道时,你必须使这些水保持在冰点以上;而当有永冻土层时,又必须保持在冰点以下。"施纳贝尔说,"所以当在冻土带中有相对温暖的水流动时,又会有一些热量散发出去。"

Similarly, when a road is built, a lot of the vegetation that insulates the permafrost is cleared and then paved over with black covering that increases the amount of absorbed solar radiation. So although the maintenance burden has increased for those like Currey, not all the distress that comes with infrastructure can be solely attributed to a changing climate.

同样,当修建一条道路,大量为冻土层保温的植被被清除,然后铺上黑色的路面,这会增加对太阳辐射的吸收。所以虽然对于像库里这样的人而言,维护工作增加了,并非所有基础设施维护的压力应该归咎于气候变化。

Defrosting a freezer full of carbon

将盛满碳物质的冻土解冻

Alaska, no doubt, is on the front lines of climate change, but the issues related to permafrost aren’t just specific to The Last Frontier. What happens to the frozen earth material in the 49th state will affect the lower 48, as well as the entire globe.

毫无疑问,阿拉斯加是气候变化影响的前沿,但对这个最后的边疆(指阿拉斯加州)而言,与冻土层有关的问题并非独一无二。在这第49个州发生的冻土问题也会影响到之前的所有48个州,乃至全球。

According to Romanovsky, half of the state’s and 90% of interior Alaska’s permafrost will thaw if there’s a global average rise of 2C in air temperature.

据罗曼诺夫斯基所说,如果全球平均气温上升2摄氏度,那么阿拉斯加一半以及阿拉斯加州内陆90%面积的永冻土将全部融化。

This is especially worrying because an enormous amount of organic carbon is sequestered in permafrost and the overlaying active layer. Since there’s not enough heat in frozen soil to help microbes to decompose dying vegetation, over thousands of years organic matter has accumulated in permafrost. Some estimates say the amount of carbon in the permafrost is more than two times than there is in atmospheric carbon dioxide.

由于大量的有机碳被封存在永久冻土层和覆盖于其上的活动层中,这一点尤其令人担忧。由于冻土中没有足够的热量帮助微生物分解垂死的植被,冻土中积聚了几千年来的有机物。一些人估计,永久冻土中的碳含量是大气中二氧化碳的两倍之多。

“If we maintain our current course of operation, business as usual they call that, then it's pretty certain by 2100 a significant fraction of the permafrost in the upper five metres would thaw out and with it all the organic matter that is currently frozen in the permafrost,” says Kevin Schaefer, a research scientist at the National Snow and Ice Data Center at the University of Colorado. “That would indicate a release of carbon dioxide and methane, which would amplify the warming due to the burning of fossil fuels.”

"如果我们保持目前的行为方式不变,那么可以肯定的是,到2100年,地表上层5米深度的一大部分永久冻土会解冻,连带现在冻结在其中的所有有机物,"科罗拉多大学(University of Colorado)国家雪冰数据中心( National Snow and Ice Data Center)的科学家凯文·谢佛(Kevin Schaefer)说,"这意味着二氧化碳和甲烷的释放,这将加剧化石燃料燃烧造成的气候变暖。"

In fact, in a 2012 report published in the journal Nature, Schaefer and his co-authors indicated that past sudden warming events were essentially triggered by the release of carbon dioxide and methane from permafrost some 50 million years ago in Antarctica.

事实上,《自然》杂志2012年发表的一份报告中,谢佛和他的合著者指出过去的那些突发变暖事件基本上是由大约5000万年前南极洲永久冻土中释放的二氧化碳和甲烷引起的。

And the projected numbers don’t look promising: “Theoretically if this carbon is released to the atmosphere, the amount of CO2 will be three times more than what is in there [in the atmosphere] now,” says Romanovsky.

而且预期的数据也不乐观。"从理论上讲如果这些碳释放到大气中,二氧化碳的含量会比现在[大气中的]含量高三倍。"罗曼诺夫斯基说。

So it's a true feedback loop as it amplifies the warming due to the burning of fossil fuels. And despite the fact that the warming is accelerating, the feedback effects will be gradual, taking time to be noticeable. “It's a very slow feedback,” Schaefer says.  “Imagine trying to steer a steam ship with a canoe paddle, that's the kind of feedback we're talking about.”

由于这将加重化石燃料燃烧而引起的气候变暖,所以这是一个真正的循环反馈。尽管气候变暖正在加速,但反馈效应却是逐步显现的,需要时间让它变得更为明显。"这是一个非常缓慢的反馈过程,"谢佛说,"想象一下用独木舟桨来让一艘蒸汽船转向,这就是我们正在谈论的反馈效应。"

Unfortunately, once permafrost starts to thaw, it’ll be hard to refreeze it again – at least in our lifetime. Furthermore, once the decay is out of the ground and into the atmosphere, there’s no easy way to put that carbon back into the ground.

不幸的是,一旦冻土开始融化,至少在我们的有生之年很难再把它们冻起来。此外,一旦腐败的物质脱离地表进入大气层,就没那么没有容易再将碳捕捉回土壤里。

“The only way to do that would be to lower the global temperature and refreeze the permafrost, which would mean you're removing carbon dioxide from the atmosphere,” Schaefer says.

"唯一的办法就是降低全球温度和并让永冻土重新冻结,这将意味着需要从大气中去除二氧化碳,"谢佛说。

Climate models show that current intergovernmental commitments to reduce warming – as laid out by the Paris Climate Accord – may not be enough, Romanovsky explains.

气候模型表明,巴黎气候协定所规定的减缓全球变暖的现行政府间的合作承诺可能是不够的,罗曼诺夫斯基解释说。

In a 2016 report published in Nature Climate Change, researchers Sarah Chadburn and colleagues estimate that even if the climate was stabilised as agreed upon by the 196 parties in 2015, “the permafrost area would eventually be reduced by over 40%”.

在一篇2016年发表在《自然气候变化》(Nature Climate Change)上的报告中,研究人员萨拉·查德博恩(Sarah Chadburn)和她的同事们估计,即使按照196个缔约方在2015年所达成的协议,并且气候最终稳定下来,"永久冻土区域最终将缩水40%以上"。

However, with US President Donald Trump’s announcement of withdrawal from the Paris agreement last June, more permafrost loss is likely on the horizon.

然而,随着美国总统唐纳德·特朗普去年六月宣布退出巴黎气候协定,可能会有更多的永久冻土消失。

The blame game

相互指责的游戏

Alaska is a politically conservative state, so outsiders might assume that residents reject the idea that the planet is warming beyond our control. The truth is more complex.

阿拉斯加是一个政治上保守的州,所以局外人可能会觉得居民们会拒绝接受地球变暖的想法。真相其实更为复杂。

According to a poll of 750 participants conducted earlier this year by the Alaska Dispatch News, more than 70% of Alaskans are concerned about the effects climate change.

根据《阿拉斯加递信报》(Alaska Dispatch News)今年早些时候对750名参与者所做的一项民意调查,超过70%的阿拉斯加人关注气候变化的影响。

“In Alaska anybody you ask will say ‘yes there's warming,’” Romanovsky says. “The farther north you go, northwest especially, the stronger that feeling. Because it's happening, you see it. Of course, the question of who's responsible depends on political beliefs.”

"在阿拉斯加,你问到的任何一个人都会说'是啊,确实在变暖',"罗曼诺夫斯基说,"越往北走,特别是往西北,那种感觉就越强烈。因为它正在发生,你可以看得到。当然,谁该对此负责取决于政治信仰。"

At Denali National Park & Preserve, park ranger Anna Moore has witnessed warming affect wildlife across only a couple of years. She’s noticed that the Arctic hare, which switches between brown and white coat colours with the seasons can’t seem to keep up with the changes as a result of temperature rise, essentially putting itself at risk.

在丹奈利国家公园保护区(Denali National Park & Preserve),公园的护林员安娜·摩尔(Anna Moore)见证了气候变暖在过去两三年间对野生动物的影响。她注意到原本随着季节的变化而在棕色和白色毛皮颜色之间切换的北极兔,由于气温上升,似乎赶不上季节的变化,实际上把自己置于危险境地。

“In the wintertime they get white tips to their hair,” Moore says. “As it gets warmer, the snow is melting faster, but their bodies are acclimatised to certain temperature change and so even though the snow is already melting they're still white and in more danger from predators.”

"在冬季,他们的皮毛尖端会变白,"摩尔说,"随着天气变暖,雪融化得更快,但他们的身体早已适应了温度变化的节奏,所以即使雪已经融化,他们还是披着白色的毛皮,更容易遭受掠食者的威胁。"

Moore says though she believes in climate change and is watching it affect flora and fauna at the park, she considers it a result of both human activities and a natural cycle.

摩尔说,尽管她相信气候变化,并且正在观察它对公园里动植物的影响,她认为这是人类活动和自然循环的结果。

Her colleague Ashley Tench also echoes the sentiment: “I agree with her [on] how it's part man-made and also natural.” To that effect, Tench doesn’t believe the United States’ pullout of the Paris Agreement makes a difference in the climate.

她的同事艾什莉·坦奇(Ashley Tench)也呼应了这种想法:"她关于部分人为和部分由于自然的观点我也赞同。"为此,坦奇不相信美国退出巴黎气候协定对气候变化有什么影响。

But not everyone in Alaska is on board with that sentiment. To Bill Beaudoin, a retired submariner and educator who’s now the proprietor of a bed and breakfast in Fairbanks, it’s obvious that humans are to blame and that we should work on reversing the effects of our actions.

但并不是每个阿拉斯加人都是这种想法。比尔·博多恩(Bill Beaudoin),是一位现在费尔班克斯市经营民宿的退休潜艇水兵和教育家。他觉得很明显,人类是罪魁祸首,我们应该努力扭转我们行为的影响。

“I think the Paris climate accord was necessary,” he says. “In fact, I didn't think [it was] enough. There's one country, Nicaragua, that didn't sign on to the agreement because they didn’t think it was strong enough. I would probably side with Nicaragua on that issue.”

"我认为巴黎气候协定是必要的,"他说,"事实上我认为这还不够。有一个国家,尼加拉瓜,没有签署协议,因为他们认为协议不够强。我在这一问题上可能会站在尼加拉瓜一边。"

No matter who is to blame for the warming and resulting thaw of permafrost, Alaskans are for the most part concerned about their future.

不管全球变暖导致的永冻土层解冻该责备谁,绝大多数阿拉斯加人都关切自己的未来。

“People are worried, because of course there's no insurance for thawing permafrost,” Romanovsky says. “Insurance is not covering damage from permafrost like it does in California for earthquakes.”

"人们担心,是因为还没有关于永冻土层融化的保险,"罗曼诺夫斯基说,"(这里的)保险不像加利福尼亚州的保险承保地震那样,会承保永冻土融化导致的损失。"

Back at Goldstream III, Romanovsky notes that at 50cm depth, the temperature of the soil is -0.04C (31.9F). At one metre it’s -0.23C (31.5F).  The last time he checked the data was in March, where at one metre, the soil temperature measured -1.1C (30F).

回到金溪三号地点,罗曼诺夫斯基发现在50cm深处,土壤的温度是零下0.04摄氏度(31.9华氏度)。而在一米深处,温度为零下0.23摄氏度(31.5华氏度)。他最后一次检查的数据是在3月份,一米深度测量的土壤温度为零下1.1摄氏度(30华氏度)。

He takes his shovel and makes a hole in the ground to look at the soil and check for carbon within. Darker soil indicates accumulated organic carbon. The further down he digs, the colder the soil gets. Romanovsky digs until the shovel hits the permafrost and seemingly can’t go any further.

他拿着铲子在地上挖了一个洞,看看泥土,检查其中的碳。更深的土壤颜色表明有机碳的积聚越多。他挖得越深,土壤就越冷。罗曼诺夫斯基直挖到永冻土层,似乎已经挖不动的地方。

He pushes down a bit more and manages to dig up a bit of the permafrost – about the size of a small coin. Seconds after he holds the frozen soil between his fingers it melts as if it were an ice cube. He returns the dug up dirt back into the hole, disconnects his laptop from the data collector, closes up the box and covers it up with branches and packs up to leave the site. In a week he’ll head up north to log the temperature at other sites adding yet more data to one of the most comprehensive permafrost databases in the world.

他再向下挖了一点,设法挖了一点冻土,大约有一枚硬币那么大。他用手指夹住几秒钟之后,冻土就像冰块那样融化了。他将挖出的泥土填回洞里,将笔记本电脑与数据采集器断开,关闭箱盖,并覆盖上树枝,装好背包离开现场。一周后,他将前往北方其他记录温度的地点,并将更多的数据添加到世界上最全面的永久冻土数据库之一。

Meanwhile, bit by bit, America’s frozen north is thawing and what happens next is unknown. What’s certain is the great thaw will forever change a once-familiar landscape – and likely a planet and its inhabitants too.

同时,一点点地,美国冰封的北方正在融化,接下来将发生什么尚未可知。可以肯定的是,这场大解冻将永远改变我们所熟悉的地表形态——很可能是整个星球还有它的居民。

相关文章列表