打破边界：我们星球的科学（2021）

系统的湿润度 所必备的最低径流水量
any given river basin must have to maintain the wetness in the system
这样就会得到蓬勃发展的生态系统
so that you have thriving ecosystems,
充足的水源充足以及良好运作的水域
good supply of water, functioning river basins.
目前 从每条河中抽取的水量
The volume of water currently being extracted from each river
揭示了为什么现在很多河流有干涸的危险
reveals why many are now in danger of running dry.
在全球范围内就我们如今的评估来看
Globally, we’re still, as far as our assessment shows today,
我们依然处于淡水安全区域
in the safe zone on fresh water,
但是我们正迅速向危险区域移♥动♥
but we’re rapidly moving towards a danger zone.
最后一条生物圈界限
The last of the biosphere boundaries
涉及到营养物、氮和磷的流动
involves the flow of nutrients, nitrogen, and phosphorus.
它们是所有生物的基本组成部分
They are the essential components of all living things,
也是肥料的关键成分
the key ingredients in fertilizers.
约翰亲眼目睹了增加使用量带来的影响
Johan has witnessed firsthand the impacts of their increasing use.
他在波罗的海的一个小岛上度过了童年的夏天
He spent his childhood summers on an island in the Baltic Sea.
我们喜欢钓鱼
We loved fishing.
我经常跟我最亲密的朋友安德斯
Most often, I fished with my closest friend here, Anders,
还有我弟弟尼克劳斯一起钓鱼而且…
and my little brother Nicklaus. And…
所以我们三个几乎经常
So there was often the three of us.
问我父母
Almost being able to tell my mother and dad that,
“晚餐你想吃点鱼吗？”
“So you want some fish for dinner?”
基本上我们回家时都会有收获
and we would come home with a catch, basically.
其中一次冒险
One of the adventures was going out
是在开阔的波罗的海一、二海里之外
one, two nautical miles out in the open Baltic,
我们可以在那里徒手抓鳕鱼
and that’s where we could, by hand, fishing cod.
我当时最擅长洗鱼
I was, at that time, the best at rinsing the fish,
一小时后 我不得不放弃钓鱼
so, after one hour, I had to abandon the fishing,
因为我们捕到特别多鳕鱼
because we got so much cod that the only way to bring it home
把它们带回家的唯一办法是在现场杀鱼
was that we would actually cut up the fish on site.
海鸥都快把我们吞没了
So we would have the seagulls just engulfing us,
因为有那么多内脏和鱼块
because there was so much, er, you know, entrails
我会把它们切下来
and then pieces of fish that I was then cutting off
装进船中
just to fit in the boat.
作为小孩子 这样做是非常兴奋的
And that was a cause of great, great excitement as a kid to do that.
几十年后的今天 情况完全不同了
A few decades later, today, it’s a completely different situation,
你会发现 没有人去捕鳕鱼
and you see nobody trying to go out to catch cod,
因为它们在这儿几乎绝迹了
because, er, it’s just literally empty.
顺便说一句 当你从上面看时它看起来与20世纪70、80年代
It looks exactly the same, by the way, as it did in the 1970s, 1980s
完全一样
when you look at it from above,
但是如果你从下面看时它就完全不同了
but when you look at it from below, it’s something completely different.
在约翰小时候 波罗的海是以鳕鱼等掠食性鱼类为主的
When Johan was a boy, the Baltic was a healthy environment
健康环境
dominated by predatory fish like cod.
虽然过度捕捞 导致许多鱼类死亡
But while overfishing removed many of the fish,
正是从周围农田冲刷下来的肥料
it was fertilizers washed off the surrounding fields
使波罗的海陷入了灾难
that tipped the Baltic into disaster.
它现在是世界上污染最严重的海洋
It’s now the world’s most polluted sea.
当这个星球上有很多跟波罗的海类似的地方时
It is when you have many Baltic Sea equivalents across the planet
我们有理由深切关注
that there is reason for deep concern,
因为这是个信♥号♥♥
because it’s a…
表明整个星球正在失去恢复能力
It’s a signal that the entire planet is gradually losing its resilience
而且渐渐变得越来越弱
and gradually becoming weaker and weaker.
埃琳娜贝内特是研究肥料影响的专家
Elena Bennett is an expert on the impacts of fertilizers.
我们从空气中提取氮气通过化学方法
We take nitrogen out of the air and chemically convert it
将其转化为能被植物利用的形式
into a form that is able to be used by plants,
或者 就磷而言我们把它从地下挖出来
or, in the case of phosphorus, we dig it up out of the ground.
我们把它开采出来
We mine it.
我们开♥发♥了化学途径或方法对磷进行开采
We developed these chemical pathways or ways to mine phosphorus
这些是更有效的做法
that were much, much more efficient,
基本上使世界各地
and that basically doubled, tripled,
食物生产增加了两倍、三倍 甚至四倍
or even quadrupled the production of food around the world.
这对养活不断增长的人口是非常宝贵的
This was invaluable in feeding a growing population,
但我们养成了施用更多肥料的习惯
but we got into the habit of applying far more fertilizer
这远远多于作物实际的施用量
than the crops could actually use.
未使用的营养物质被冲入河流
The unused nutrients wash into rivers,
使得河流也过量施肥
over-fertilizing them too.
这个过程称为“富营养化”
A process called eutrophication.
我们看到的是这些藻华
What we see are these algal blooms.
它看起来像是湖顶上的蓝绿色浮渣
Sort of looks like a blue-green scum on top of the lake.
它们的气味通常很难闻
They often smell terrible
因为我们闻到的是藻类腐烂的味道
because we’re smelling the rotting of that algae.
它在腐烂时会消耗氧气
As it’s decomposing, it uses up oxygen.
减少的氧气会改变了
Reduced oxygen changes the chemical composition
湖底沉积物的化学成分导致它释放出更多的磷
of the sediment on the bottom of the lake, causing it to release more phosphorus.
一旦出现了富营养化问题
Soon as you have a eutrophication problem,
湖水会这样想
the lake sort of says,
“很好 我们会把情况弄得更糟”
“Oh good, we’re gonna make it worse,”
它就创造了一个正反馈循环
and it just creates a positive feedback cycle
这会产生越来越多的磷
that creates more and more and more phosphorus
进入湖中并从根本上使其保持这种状态
going into that lake and essentially keeps it in that state.
我们在海洋中 也有同样的富营养化问题
We also have the same issue of eutrophication in oceans,
我们从同样的营养物质中 得到所谓的死亡区
where we get what are called dead zones from the same nutrients,
在全世界几百个地方
and we see those dead zones now
都能看到死亡区
in a few hundred places around the world.
海洋中的富营养化可能是导致世界上
Eutrophication in the ocean may have been an important contributor
前五次大灭绝事件之一的重要因素
to one of the world’s five previous mass extinction events.
如今 一些死亡区已经扩大到
Already today, some dead zones have expanded
覆盖数万平方公里
to cover tens of thousands of square kilometers.
我们对磷和氮的过度使用
Our overuse of phosphorus and nitrogen
是我们对生物圈造成的最不为人知
is one of the least known, but most critical impacts
但又最关键的影响之一
we’re having on the biosphere.
我们已经深陷危险区域了
We are already deep into the danger zone.
我们已经越过营养物质界限了
We are well across the nutrient boundary.
这不是我们会经常想到的事
It’s… It’s not a thing that we think about very often.
我认为我们需要比现在更加认真地对待这个边界
I think we need to be taking this boundary much more seriously than we currently are.
营养物质、水、我们的森林 生物多样性和气候
Nutrients, water, our forests, biodiversity, and the climate.
是我们的星球调节稳定性 以及支撑我们自身生存的
Five big components of our planet that regulate stability
五大要素
and underpin our own survival.
但是约翰和他的同事知道 这还不是全部
But Johan and his colleagues knew that this still wasn’t the full picture.
他们还没有考虑到正在海洋中上演的
They hadn’t yet accounted for a little-known drama
一场鲜为人知的戏剧性事件
that’s playing out in the oceans.
它对我们星球稳定性的影响 可能会超过所有其它影响
Its impact on our planet’s stability could outplay all others.
当我们把二氧化碳排入大气时
When we emit CO2 into the atmosphere,
大约三分之一最终进入了海洋
about a third of that emissions has ended up in the ocean.
特里休斯多年来 一直与约翰
Terry Hughes has been a close collaborator with Johan
密切合作
over many years.
这已经改变了海洋的化学成分
That has changed the chemistry of the ocean.
它已经改变了酸碱度
It has changed the pH
使其碱性降低或酸性增强
and made it less alkaline, or more acidic.
因此被称为 “海洋酸化”
Hence the name “ocean acidification.”
当二氧化碳在水中溶解时
When carbon dioxide dissolves in water,
产生了碳酸
it creates carbonic acid.
较冷的水域有其脆弱性
The vulnerability is in colder waters.
在过去的几十年间
Over the past few decades,
世界海洋的酸度增加了26％
the world’s ocean has become 26% more acidic,
只要大气中的二氧化碳
and, for as long as carbon dioxide concentrations
浓度依然很高
in the atmosphere remain high,
海洋就会继续酸化
the ocean will continue acidifying.
酸与水中被称为碳酸离子的化学物质发生反应
The acid reacts with chemicals in the water called carbonate ions,
降低它们的浓度
reducing their concentration.
它会影响到各种各样的生物体
It affects a broad suite of organisms,
特别是那些需要碳酸盐
particularly those that need
让骨骼生长的生物体
carbonate to grow their skeletons.
像是软体动物、牡蛎和蚌类
Things like mollusks, oysters, mussels.
海洋酸化有一段不祥的历史
Ocean acidification has an ominous history.
海洋酸化和酸碱度的
Global changes in the acidification,
全球性变化实际上会导致大规模物种灭绝
the pH of the ocean, can actually cause mass extinctions.
我们在地质记录中多次看到了这种情况
We’ve seen that repeatedly in the geological record.
因此 当我们在操纵
So as we manipulate
这个星球的气候时我们实际上是在玩火
the planet’s climate, we’re literally playing with fire
因为越过这些地球界限
in terms of the unforeseen consequences
进入未知的领域 会造成不可预见的后果
of moving past these planetary boundaries into uncharted territory.