难以忽视的真相（2006）

这是荷兰的一项研究
Here is a study from the Netherlands.
鸟类迁徙的高峰期
The peak arrival date for migratory birds
25年前是4月25日
25 years ago was April 25th,
6月3日雏鸟孵化出壳
and their chicks hatched on June the 3rd.
此时毛虫刚好出来活动
Just at the time when the caterpillars were coming out.
配合得天衣无缝
Nature’s plan.
20年的升温
But 20 years of warming later,
造成毛虫活跃高峰期提前2周
the caterpillars peaked two weeks earlier,
尽管雏鸟试图适应 却无法跟上
and the chicks tried to catch up with it, but they couldn’t.
这样就带来了问题
And so, they’re in trouble.
现在有无数这样的生态位
And there are millions of ecological niches
正受到全球变暖的影响
that are affected by global warming in just this way.
这是过去100年
This is the number of days with frost in Southern Switzerland
瑞士南部结冰的天数
over the last 100 years.
正急剧下降 但是请看这个
It has gone down rapidly. But now watch this.
这是入侵的外来物种
This is the number of invasive exotic species
急剧增长 填补增加的生态位
that have rushed in to fill the new ecological niches that are opening up.
在美国有同样的情形
That’s happening here in the United States, too.
各位都听说过”松树甲虫”事件
You’ve heard of the pine beetle problem?
过去 这些松树甲虫会被严冬冻死
Those pine beetles used to be killed by the cold winters,
但结冰的天数减少
but there are fewer days of frost,
松树于是遭到破坏
and so the pine trees are being devastated.
在阿♥拉♥斯加有1400万亩云杉
This is part of 14 million acres of spruce trees in Alaska
被皮蠹虫破坏 是一样的现象
that have been killed by bark beetles. The exact same phenomenon.
有的城市得以建立
There are cities that were founded
是因为高于蚊子活跃区
because they were just above the mosquito line.
如奈洛比 哈拉雷 以及其他一些城市
Nairobi is one, Harare is another. There are plenty of others.
如今随着温度升高 蚊子飞到更高的地方
Now the mosquitoes, with warming, are climbing to higher altitudes.
一些令人不安的传染病
There are a lot of vectors for infectious diseases that are worrisome to us
也传播得越来越广
that are also expanding their range.
除了蚊子 还有其余这些
Not only mosquitoes, but all of these others as well.
在过去的25年里
And we’ve had 30 so-called new diseases
又发现了30种所谓的”新疾病”
that have emerged just in the last quarter century.
比如造成了严重影响的”非♥典♥”
And a lot of them, like SARS, have caused tremendous problems.
就是肺结核的新变种 还有其他的疾病
The resistant forms of tuberculosis. There are others.
还有一些疾病死灰复燃
And there’s been a re-emergence of some diseases
尽管曾经被人类征服
that were once under control.
众人熟知的禽流感 就是一个严重的例子
The avian flu, of course, quite a serious matter, as you know.
西尼罗热
West Nile Virus.
1999年登陆马里兰东岸
It came to the eastern shore of Maryland in 1999.
2年后就越过了密西西比
Two years later, it was across the Mississippi.
又是2年过去 它已经肆虐整个大♥陆♥
And two years after that, it had spread across the continent.
这都是很隐蔽的信♥号♥♥
But these are very troubling signs.
世界各地的珊瑚礁
Coral reefs all over the world,
由于全球变暖等原因
because of global warming and other factors,
正逐渐褪色 变成这个样子
are bleaching and they end up like this.
那些依赖珊瑚礁的鱼类
And all the fish species that depend on the coral reefs
也濒临灭绝
are also in jeopardy as a result.
总的来说 现在物种灭绝的速度
Overall, species loss is now occurring
超过自然速度的1000倍以上
at a rate 1,000 times greater than the natural background rate.
这也引出了第二大”警钟”
This brings me to the second canary in the coal mine.
南极
Antarctica.
目前地球上最大面♥积♥的冰层
The largest mass of ice on the planet by far.
我的一位朋友1978年说
A friend of mine said in 1978,
“要是你看到南极半岛的冰架裂开”
“If you see the breakup of ice shelves along the Antarctic peninsula,
“要小心”
“watch out
“这应该看作是全球变暖的征兆”
“because that should be seen as an alarm bell for global warming.”
事实上 要是仔细观察南极半岛
And actually, if you look at the peninsula up close,
这些绿斑所在之处
every place where you see one of these green blotches here
就是过去15到20年里断裂的冰架
is an ice shelf larger than the state of Rhode Island
它们的规模都超过了罗得岛州
that has broken up just in the last 15 to 20 years.
我想关注一个冰架
I want to focus on just one of them.
它叫做拉森-B
It’s called Larsen B.
请各位看这里的黑块
I want you to look at these black pools here.
看起来就像穿过了冰层
It makes it seem almost as if we’re looking through the ice
看到了下面的海洋 但这只是错觉
to the ocean beneath. But that’s an illusion.
这些都是正在融化的冰水
This is melting water that forms in pools,
要是坐在直升机上飞过
and if you were flying over it in a helicopter,
你会看到它高达700尺
you’d see it’s 700 feet tall.
无比宏伟
They are so majestic, so massive.
远处是冰山 而冰山前面
In the distance are the mountains and just before the mountains
就是冰架
is the shelf of the continent, there.
这是浮冰
This is floating ice,
这是陆地沿着山坡延伸的冰层
and there’s land-based ice on the down slope of those mountains.
从这里到冰山有大约20到25英里
From here to the mountains is about 20 to 25 miles.
人们原以为尽管全球变暖
Now they thought this would be stable for at least 100 years,
这里不会有什么变化
even with global warming.
但是研究这个的科学家
The scientists who study these ice shelves
看到这些画面时
were absolutely astonished
大吃一惊
when they were looking at these images.
从2002年1月31日起
Starting on January 31, 2002
短短35天内
in a period of 35 days
冰架完全消失了
this ice shelf completely disappeared.
他们都弄不明白 世界变化怎会如此之快
They could not figure out how in the world this happened so rapidly.
他们回过头来检查
And they went back to try to figure out where they’d gone wrong.
结果发现了这些融化的冰水
And that’s when they focused on those pools of melting water.
就在他们还没有弄明白究竟时
But even before they could figure out what had happened there,
又发生了别的事情
something else started going wrong.
当漂浮的海基冰层破裂
When the floating sea-based ice cracked up,
它不能再保持陆地的冰层
it no longer held back the ice on the land,
结果陆基冰层开始掉入海洋
and the land-based ice then started falling into the ocean.
就像是瓶塞被顶出酒瓶一样
It was like letting the cork out of a bottle.
浮冰和陆基冰层并不相同
And there’s a difference between floating ice and land-based ice.
就好比杯子里的冰块
That’s like the difference between an ice cube floating in a glass of water,
一个浮在水面 融化之后不会使水位升高
which when it melts doesn’t raise the level of water in the glass,
另一个堆在水里
and a cube that’s sitting atop a stack of ice cubes
融化后使水漫了出来
which melts and flows over the edge.
这就是为什么 太平洋沿岸的人♥民♥
That’s why the citizens of these Pacific nations
得疏散到新西兰
have all had to evacuate to New Zealand.
现在我想关注南极洲西部
But I want to focus on West Antarctica
因为它体现了陆基和海基冰层两大要素
because it illustrates two factors about land-based ice and sea-based ice.
它两者兼有 因为它其实是由许多小岛组成
It’s a little of both. It’s propped up on tops of islands,
而海洋就在其下面
but the ocean comes up underneath it.
所以海洋升温会对其产生影响
So as the ocean gets warmer, it has an impact on it.
如果它消失了
If this were to go,
全球海面会升高20英尺
sea level worldwide would go up 20 feet.
人们监测了冰原底层的异常变化
They’ve measured disturbing changes on the underside of this ice sheet.
对于另一个 相同大小的冰层而言
It’s considered relatively more stable, however,
它的变化还算相对稳定的
than another big body of ice that’s roughly the same size.
若格陵兰消失 同样可以使海面上升20尺
Greenland would also raise sea level almost 20 feet if it went.
我的一个朋友刚刚带回来一组照片
A friend of mine just brought back some pictures
关于格陵兰的近况
of what’s going on on Greenland right now.
戏剧性地 这里也有类似的冰泊
Dramatic changes. These are the same kinds of pools
同南极的冰架情形一样
that formed here, on this ice shelf in Antarctica.
科学家以为
And the scientists thought
水一遇到冰 就会冻起来
that when that water seeped back into the ice, it would just refreeze.
但他们发现事实上
But they found out that actually what happens
水一直往里流 一直延伸到底部
is that it just keeps on going. It tunnels to the bottom
整个冰架就像一块瑞士奶酪一样
and makes the ice like Swiss cheese,
或是白蚁洞
sort of like termites.
这里展示了裂隙造成的后果
This shows what happens to the crevasses,
一旦形成了湖 就会产生冰川蜗穴
and when lakes form, they create what are called moulins.
水一直流到底部
The water goes down to the bottom
在底部的冰和基岩之间起到润滑作用
and it lubricates where the ice meets the bedrock.
这里是一群人在勘测
See these people here for scale.
而这不是在格陵兰岛边缘 而是在冰层正中间
This is not on the edge of Greenland, this is in the middle of the ice mass.
出现了冰雪融水组成的湍急水流
This is a massive rushing torrent of fresh melt water
穿透格陵兰的冰层
tunneling straight down through the Greenland ice
直流入底部的基岩
to the bedrock below.
尽管冰层一直都有季节性的融化
Now, to some extent, there has always been seasonal melting