打破边界：我们星球的科学（2021）

我们仍然处于海洋酸化的安全区域
We are still in the safe zone for ocean acidification,
但是我们正在向危险区域推进
but we’re pushing towards the danger zone
并有可能发生灾难性的大规模灭绝
and potentially a catastrophic mass extinction.
对于地球上所有的复杂情况
For all the complexities of Earth,
约翰和他的同事发现只有九个系统
Johan and his colleagues discovered that there are just nine systems
能让我们的星球维持稳定
that keep our planet stable.
但是他们还没有确定 这两者之间的界限在哪里
But they’ve not yet identified where the boundaries lie for two of them.
第一个是人为制♥造♥的各种污染物
The first one is an assortment of human-made pollutants.
我们称之为“ 新实体”涵盖的东西应有尽有
We call it “novel entities,” and it is everything from nuclear waste
核废料到持久性有机污染物
to persistent organic pollutants
到重金属含量
to loading of heavy metals
再到微塑料
to microplastics.
人类创造了10万种新材料
Humans have created 100,000 new materials,
其中任何一种都可能以灾难性的方式与环境相互影响
any number of which could interact with the environment in catastrophic ways.
到目前为止 这个界限还没有被量化
As of yet, this boundary is not quantified.
我们只是不知道这些污染物质的长♥期♥
We simply don’t know the long-term or cumulative impacts
或累积性影响
of these polluting substances.
但如果不以某种方式加以控制
But most have the potential to cause planet-wide disruption
大多数都可能造成全球范围内的破坏
if not controlled in some way.
有一种形式的污染物已经对全球造成了影响
There’s one form of pollutant that is already having a global impact.
以致于它有了自己的界限
So much so that it has a boundary of its own.
气溶胶基本上是大气中的颗粒物
Aerosols are basically particles in the atmosphere.
它们就是所谓的空气污染颗粒物
They are what’s called air pollution particulates.
气溶胶
75％的气溶胶污染来自化石燃料燃烧
75% of the aerosol pollution is from fossil fuel combustion.
我们把它们看成是朦胧的天空
We see them as hazy sky,
因为它们拦截阳光然后像镜子一样把阳光散射开来
because they intercept sunlight and just scatter it like mirrors.
它们造成了所谓的”全球变暗现象”
And they cause what’s called “global dimming.”
维拉布哈德兰一生都在研究 我们周围和上方的空气
Veerabhadran has spent a lifetime studying the air around and above us.
气溶胶对气候影响的另一种方式
The other way aerosols impact climate,
因为你在阻断阳光这个驱动地球温度的
because you’re cutting sunlight, which is the major energy source
主要能源而这些气溶胶造成了一些降温
for driving the temperature of the planet, these aerosols have caused some cooling.
当你听到像我这样的气候科学家说气溶胶正在给这个星球降温
When you hear climate scientists like me say that aerosols are cooling the planet
并且掩盖了升温你可能会想：“这是件好事”
and mask the warming, you may think, “That’s a good thing.”
但不幸的是 这不是件好事
But unfortunately, it’s not.
因为这种掩盖
Because of this masking,
我们依然没有看到温室怪兽的全貌
we are still not seeing the full greenhouse beast.
气溶胶的冷却效应正在掩盖
This cooling effect from aerosols is masking
全球变暖约40%的影响
about 40% of the effects of global warming.
而这需要付出高昂的代价
And it comes at a high price.
空气污染每年造成700多万人死亡
Air pollution kills over seven million people every year
并让我们所有人的平均预期寿命减少三年
and takes, on average, three years off the life expectancy of each one of us.
空气污染的界限
Where the boundary for air pollution lies
还没有科学判定
has not yet been scientifically determined.
仅仅根据这些颗粒物
Just based on the 7.5 million deaths by these particles,
造成750万人死亡这个事实 可以说
I would say we have already crossed the boundary
我们已经越过了气溶胶的界限
as far as aerosols are concerned.
最后 第九条界限是臭氧层
Finally, the ninth boundary is the ozone layer.
它的独特之处在于 它是我们朝着
It has the unique distinction of being the only boundary
正确方向前进的唯一界限
where we’re moving in the right direction.
臭氧会拦截有害的紫外线辐射
The ozone intercepts harmful ultraviolet radiation,
紫外线辐射会直接影响我们的DNA
which directly impacts our DNA
并导致诸如皮肤癌的致命疾病
and causes deadly diseases like skin cancer.
这就是
That is why,
为什么20世纪80年代 在南极洲发现臭氧层空洞时
when the Antarctic ozone hole was discovered in the 1980s,
出现了全球性的恐慌
there was a global panic.
臭氧层空洞
The discovery of the ozone hole
是由释放到大气中的化学污染物造成的
caused by chemical pollutants being released into the atmosphere
这一发现说服各国逐步淘汰了这些化学品
persuaded nations to phase out these chemicals.
把科学警告转化为政♥治♥行动
It was quite fantastic how the scientific warnings
真的很神奇
translated into political action.
这是第一个 也是唯一一个例子
This is the first and only example
证明我们可以真正管理好整个星球
that we can actually manage the whole planet.
我们实际上可以回到地球界限的安全运行空间
We can actually return into a safe operating space
因为我们真的已经进入了高风险区
for a planetary boundary that we had seriously gone into the high-risk zone,
然后我们又回到了安全运行空间
and we returned back into a safe operating space.
这的确是神奇的见证
It was indeed fantastic to witness.
科学家们发出了警报而世界也采取了行动
Scientists raised the alarm, and the world acted.
感谢约翰与他的同事
Thanks to Johan and his colleagues,
我们现在知道这个星球有九条界限
we now know the planet has nine boundaries
以及我们越过它们所面临的风险
and the risks we face by crossing them.
加上臭氧层 我们至少现在
Together with the ozone layer, we are, at least for now,
处于海洋酸化和淡水的安全区域内
within the safe zone for ocean acidification and fresh water.
我们还不知道距离空气污染或所有其它污染物
We don’t yet know how close we are to the danger zone for air pollution,
这些新型实体的危险区域有多远
or for all the other pollutants, the novel entities.
但是最令人担心的是 我们已经越过了
But most worryingly, we have already exceeded
九条界限中至少四条
at least four of the nine boundaries.
它们是气候、森林流失营养物质和生物多样性
Climate, forest loss, nutrients, and biodiversity.
我们现在正在越过不可逆转的临界点
We are now crossing irreversible tipping points,
我们正在冒着危险 接近让地球进入无法支持
and we are perilously close to tipping the Earth
我们自身文明的状态
into a state that is unable to support our own civilizations.
我们今天所看到的 证实了地球界限框架
What we’re seeing in the world today verifies the planetary boundary framework.
我们可以看到很明显的证据
We can see so clear evidence that,
因为我们处在气候的危险区域
because we’re in the danger zone on climate,
因为我们处在生物多样性丧失的深度高危区
because we’re in the deep high-risk zone on biodiversity loss,
我们开始看到日益增多的旱灾 对雨林的影响
we start seeing increased drought, impacts on the rain forest,
澳大利亚与亚马逊的森林火灾
the forest fires in Australia and in the Amazon,
加速的冰层消融 以及珊瑚礁系统的崩塌
the accelerated ice melt, the collapse of coral reef systems.
对于见证地球这些变化的科学家而言
For the scientists bearing witness to these planetary changes,
损失的不仅仅只是数字
the loss is much more than just numbers.
特里休斯一生致力于研究珊瑚礁
Terry Hughes has spent a lifetime studying coral reefs.
白化的珊瑚病得很厉害
A bleached coral is very, very sick.
当珊瑚周围的水温过高时 就会发生白化现象
Corals bleach when the waters around them get too warm,
作为全球变暖的结果 这种情况发生的频率和强度
something that’s happening with increasing frequency and intensity
与日俱增
as a consequence of global warming.
在极端高温下 就像我们最近几十年
In big thermal extremes, like we’ve been seeing
在大规模白化事件中看到的那样
during mass bleaching events in recent decades,
它们会很快死去
they can actually die very, very quickly.
它们遭到了高温破坏
They cook.
白化事件的足迹比最极端的第五类
The footprint of a bleaching event is ten times bigger
热带气旋大十倍
than the most extreme Category 5 tropical cyclone.
所以就影响的大小和发生的频率而言
So they’re off the scale in terms of the size of the impact,
它们已经超出了设定范围
and in terms of how frequently they are occurring.
特里对世界上最大的珊瑚礁系统
Terry studies the Great Barrier Reef,
大堡礁进行了研究
the largest reef system in the world.
白化事件曾经是局部性的而且很罕见
Bleaching events used to be localized and rare,
但是在过去的20年间
but over the past two decades,
海洋热浪造成了广泛的白化现象
marine heatwaves have caused widespread bleaching.
在过去五年里 发生了五起最大白化事件中的三起
Three of the five biggest bleaching events have occurred in the past five years.
我们对两次白化事件之间
We’re worried about that shrinking gap
不断缩小的间隔深感忧虑
between one bleaching event and the next one.
我们已经看到大堡礁在2016和2017年
We’ve already seen back-to-back bleaching events
连续两个夏天 第一次发生了
occur for the first time on the Great Barrier Reef
连续白化事件
in two consecutive summers in 2016 and 2017.
那些间隔对珊瑚的恢复非常重要
Those gaps are critically important if the corals are to recover.
珊瑚礁的一半珊瑚已经死亡
Half the reef’s corals have already died.
特里的工作包括进行航♥空♥测量
Terry’s work involves conducting aerial surveys
记录每次白化事件的程度
to record the extent of each bleaching event.
当我们进行航♥空♥测量时 我们尽可能飞得很慢
When we do our aerial surveys, we fly as slowly as we can,
也尽可能飞得很低这样我们就能看到单个珊瑚
as low as we can, so we can see individual corals,
我们可以评估其中有多少白化或未白化的珊瑚
and we can assess how many of them are bleached white or not.
所有珊瑚均已白化
All the coral’s bleached.
是的 很糟糕
Yeah, that’s bad.
你可以在几公里外看到一片白化的珊瑚礁
You can actually see a bleached reef from kilometers away,
因为它会发光 上面有很多白色的珊瑚
because it virtually glows.There’s so much white coral on it.
我在非常开阔的高处看到几乎所有珊瑚都白化了
So I’ve got very broad crest, and just about everything’s bleached.
现在那些测量已经进行了五次
Those surveys have now been done five times,
我领导了其中的三次
and I have led three of those.
最后三次是在2016年2017年和2020年进行的
The last three in 2016, 2017, and 2020.
这是我希望自己永远不必做的工作
It’s, um…,It’s a job I’d hoped I’d never have to do,
因为威胁近在眼前