BBC.地平线.2012.全球怪象

蓝色是什么意思 它代表低温预警
What does all the blue mean? Well that's a freeze warning...
这是一场罕见的大旱
We are seeing an incredible drought.
罗恩·罗伯茨
气象学家
这是该地区有史以来最严重的干旱
This is the worst drought in climate history for this region.
只有10厘米的降水
Only four inches of precipitation.
在此之前最严重的那次
The worst drought before this -
即70年前的干旱也有20厘米的降水
eight inches about 70 years ago.
这下你知道这次干旱有多严重了
That should give you a pretty good idea of how severe this is.
从没有过这样的干旱
We've never had a drought like this.
确保您
Also make sure that you...
这又是一个打破天气纪录的例子
It's yet another example of a weather record being broken.
早上出去遛宠物
pets out there in the morning...
预报天气并没有因此变得简单
It doesn't make forecasting the weather any easier.
我觉得这是最难预报的几年
Actually I think this is one of the toughest years to forecast.
因为这是场干旱
Because it is a drought,
而大家都希望它尽快结束
but everybody wants the drought to end.
什么时候才会下雨
When's it going to rain? When's it going to rain?
干旱时压力大多了
There's more pressure during a drought.
因为人们迫切想知道该做什么
There's more pressure to know what they need to do.
情况已经不能更糟了
The stakes couldn't be higher.
一位世界顶级的气候学家
Trying to get to the bottom of this
想要一探事情的究竟
is one of the world's leading climate scientists.
凯瑟琳·海霍教授
Professor Katharine Hayhoe
想要了解大旱原因 这不仅出自学术兴趣
has a more than academic interest in figuring out what's happening.
她就在西德州居住和工作
She lives and works in West Texas.
我们从日常生活中
What we are experiencing ourselves,
凯瑟琳·海霍教授
德州理工大学
可以明显感受到
in the places where we live our day-to-day lives,
我们习惯的天气在发生变化
is changes in the average conditions that we're used to.
我们最先看到的就是极端天气的变化
One of the first things we're seeing is changes in our extremes.
这就是"全球怪象"
We're seeing global weirding.
她帮助普及了"全球怪象"这一说法
Global weirding is a phrase she helped popularise.
西德州古怪天气成因的一个线索
One of the clues to the weirding of the West Texas weather
就藏在她脚下
lies right under her feet.
这是些西德州的泥土
What we got here's some West Texas dirt,
很好的泥土
and this is good dirt
尽管风吹起来就像沙子一样
even though it's blowing away like sand,
那是因为太干了
it's just very very dry.
现在比正常情况要干燥太多
Right now we're below 99%, below average right now -
比平均值低太多都无法测量有多干
so far below average we can't measure how dry it is.
随着土地越来越干
As the soil becomes drier and drier,
干旱也越来越严重
the drought gets worse and worse.
由于土壤中没有水分蒸发形成降雨
And that gets amplified because there's no moisture left in the soil
旱情恶性循环
to evaporate into rain.
但西德州气候奇怪之处在于
But the weird thing about the weather in West Texas
这场史无前例大旱出现的前一年
is that the year before this record-breaking drought,
西德州干旱的大地曾被倾盆大雨浸透
these bone-dry fields were awash in rain.
当时降雨量之大同样史无前例
So much rain that it broke all records.
连续两年出现极端天气
Two record-breaking years back-to-back
在这片土地上还是头一遭
is unheard of in this part of the world.
我们担心的是
The thing that we are concerned about
露点 空气湿度达到饱和时的温度
露点会有所升高
is that the dew points are going to be a little higher...
拉伯克 美国德克萨斯州城市
我们记录了拉伯克近一百年来的气候
We have 100 years of climate history in Lubbock.
在这期间从未在两年内
In those 100 years we've never had
出现如此剧烈的降水波动
this kind of steep oscillation go from one year to the next.
正常的降水变动
So something obviously is impacting
明显受到某种因素的影响
our natural variabilities that we have every year.
多年来
Over the years,
当地气候在干燥与湿润间自然交替
the weather here naturally swings between wet and dry.
但交替从未如此极端
But the swing has never been this extreme,
以至在一年内彻底颠覆了气候记录
rewriting the record books in the space of 12 months.
究竟为何极端的旱涝天气
So how can it be record-breaking wet and dry
会几乎同时出现
at virtually the same time?
在过去的一个世纪中
Our planet has warmed by
全球气温上升了近一摄氏度
almost one degree Celsius over the last 100 years.
这是十分微小的温度变化
A tiny change in temperature.
这能有什么影响呢
How could that make a difference?
气温变化本身
That temperature change, in and of itself,
对我们的生活毫无影响
makes no difference at all to our lives.
却彻底改变了我们已习惯的气候
It makes a huge difference to what we're used to.
当地天气拥有全球怪象的所有特征
The weather here has all the hallmarks of global weirding.
这里或许不常降雨
It may not rain as often
雨水也不规律
or as regularly,
这使干旱成为可能
which makes droughts possible.
但降雨来临时
But when it does rain,
雨量却更大
it's heavier
来势也更猛烈
and more intense.
我们观察到的一个变化是全球平均湿度
One of the changes we've seen is that the average humidity
上升了百分之四
of our planet has increased by 4%.
温暖的大气能容纳更多水蒸气
Warmer air holds more water vapour.
因此平均来讲 大气较三四十年前
So, on average, our atmosphere is 4% more humid
湿度增加了4%
than it used to be 30 or 40 years ago.
这对西德州的居民♥意♥味着什么呢
What does this mean for us in West Texas?
这里的湿度大概是10%
Our humidity's what, 10% probably,
因此没有感觉到太大变化
so we don't feel that so much here.
但事实上大气中蕴含了更多水蒸气
But what happens is there's more water vapour in the atmosphere.
因此当风暴过境时
So when storms come through,
更多的水蒸气会进入风暴 形成降水
there's more water for them to pick up and dump.
正是这些风暴 或缺少这些风暴
It's these storms, or lack of them,
造成了西德州极端干旱或湿润的天气
that trigger the extreme dry and wet weather in West Texas.
科学家认为
In the future,
这种旱涝交替的极端气候
scientists expect this pattern of drought and flooding
将在未来影响全球
to be played out across the planet.
但平均气温的微小变化
But it's the small change in average temperature
才是增加极端气候发生频率的始作俑者
that's behind the predicted increase in some extreme weather events.
科学家认为平衡是关键
And scientists believe it's all a question of balance.
地球努力维持气候稳定的同时
As the Earth struggles for climate stability,
天气开始极端化
the weather begins to get extreme.
并变得反常
and weird.
地球十分复杂
Our planet's a really complex place.
我们造成气温上升的同时
So as we increase the temperature of our planet,
也改变了大气的动力学
we are changing the dynamics of our atmosphere,
以及天气系统在国内运动的方式
we are changing the way our weather systems move across the country.
我们在改变 亚♥热♥带在扩张
We're changing... our sub-tropical zones are expanding,
全球干旱地区在扩大
our dry areas of the world are actually growing.
我们改变了全球降水的分布
So we are changing how water gets distributed around our planet.
干旱地区更加干旱
Places that are already dry are getting drier.
湿润地区更加湿润
Places that are already wet are getting wetter.
两种天气都更加极端
And our extremes are getting stronger in both directions.
无论气候反常是自然引起的
Whether this warming is natural or man-made,
或像大部分科学家认为的那样 是人为的
as the vast majority of scientists believe,
反常的气候正在促成全球性的变化
it's triggering global changes.
英国也将受到波及
And they are expected to play out in Britain.
今年有关气候变化风险的政♥府♥报告指出
This year's government report on climate change risk
我们面对更多洪灾的同时
says we are likely to see more flooding on the one hand,
也将迎来更长的旱季
and longer drier spells on the other.
去年苏格兰地区史无前例的降水量
The record-breaking rains in Scotland last year
以及英格兰东部史上最严重的春旱
and the worst spring drought ever in parts of eastern England
或许是灾难的前兆
could be a taste of things to come.
但更引人关注问题是
But the intriguing question
这种气候对冬季可能产生的影响
is the effect it might have been having on our winters.
2009年圣诞将近时
As Christmas 2009 approached,
英国开始瑟瑟发抖了
Britain started to shiver.
今晚可能迎来史无前例的低温
Yeah, it could be a record-breaking cold night tonight...
寒冷日复一日
The cold went on, day after day.
气温将持续下降
Temperatures are going to plunge further as the day goes on...
那是三十年来最寒冷的冬天
It was the coldest winter for 30 years.
仅一年后 纪录再次被打破
Just a year later, records were being broken again.
2010年12月
December 2010 was the coldest