(Beeps)

（嗶嗶聲）

[Countdown]

[倒數計時]

(Clapboard claps)

（場記板打板）

Ten years is a long time for us humans on earth.

對地球上的我們來說，十年很長。

Ten turns around the sun.

我們繞太陽轉十圈。

When I was on the TED stage a decade ago,

十年前，我在 TED 演講時，

I talked about planetary boundaries

我談論了「地球承載界限」，

that keep our planet in a state that allowed humanity to prosper.

它能讓人類在地球上維持昌盛的狀態。

The main point is that once you transgress one,

其重點在於， 一旦超越了一項承載界限，

the risks start multiplying.

風險便開始大幅增加。

The planetary boundaries are all deeply connected,

每項地球承載界線都息息相關，

but climate, alongside biodiversity, are core boundaries.

其中以氣候、生物多樣性為核心，

They impact on all others.

進而影響其他承載界線。

Back then we really thought we had more time.

那個時候，我們真的以為還有很多時間。

The warning lights were on, absolutely,

警示燈的確是亮了，

but no unstoppable change had been triggered.

但不可挽回的變化尚未觸發。

Since my talk, we have increasing evidence

自從我上次的演講， 有越來越多證據顯示

that we are rapidly moving away

我們正在加速遠離

from the safe operating space for humanity on earth.

人類在地球上所能安全運作的空間。

Climate has reached a global crisis point.

氣候已經到達全球危機的程度。

We have now had 10 years of record-breaking climate extremes:

我們已經連續十年 出現破記錄的極端氣候，

fires blaze in Australia, Siberia, California and the Amazon,

烈火在澳洲、西伯利亞、 加州、亞馬遜蔓延；

floods in China, Bangladesh and India.

洪水在中國、孟加拉、印度肆虐。

We're now enduring heat waves across the entire northern hemisphere.

如今整個北半球也正遭受熱浪襲擊。

We risk crossing tipping points

我們就快要跨過那個臨界點；

that shift the planet from being our best resilient friend,

原本地球用超強復原能力

dampening our impacts,

幫我們減緩氣候衝擊，

to start working against us, amplifying the heat.

現在變成跟我們作對，升高氣溫。

For the first time, we are forced to consider the real risk

這是我們第一次被逼著正視

of destabilizing the entire planet.

破壞整個星球平衡所帶來的真正風險。

Our children can see this.

我們的下一代都意識到了。

They are walking out of school to demand action,

他們走出學校，要求有所行動，

looking with disbelief at our inability to deviate away

對我們無能為力帶著他們 遠離潛在的災難風險，

from potentially catastrophic risks.

他們感到不可置信。

The next 10 years, to 2030,

到 2030 年的下個十年內，

must see the most profound transformation the world has ever known.

這個世界一定會經歷史上最嚴峻的轉變

This is our mission.

這是我們的使命。

This is the countdown.

這是倒數計時。

(Clock ticks)

（時鐘滴答響）

When my scientific colleagues summarized, about a decade ago,

一開始，大約十年前，

for the first time,

我的科學家同儕當時的結論是，

the state of knowledge on climate tipping points,

從目前對氣候臨界點的認知看來，

just one place had strong evidence that it was on a serious downward spiral.

只有一個地方有強烈證據顯示 情勢在迅速惡化，

Arctic sea ice. (Water sounds)

那就是北極海冰層； （水聲）

Other tipping points were long way off --

其他的臨界點都還離我們很遠——

50 or 100 turns around the sun.

還要再繞太陽 50 或 100 圈。

Just last year we revisited these systems,

但就在去年，我們重新審視這些系統，

and I got the shock of my career.

我感到職涯中前所未有的震驚：

We are only a few decades away from an Arctic without sea ice in summer.

再幾十年，北極的夏天就不會有海冰。

In Siberia, permafrost is now thawing at dramatic scales.

現在，西伯利亞永凍層 正以驚人速度融化；

Greenland is losing trillions of tons of ice

格陵蘭流失數兆噸的冰，

and may be approaching a tipping point.

可能就快接近其臨界點；

The great forests of the North

北方森林大火，

are burning with plumes of smoke the size of Europe.

產生的煙霧範圍有歐洲大陸之大；

The Atlantic ocean circulation is slowing.

大西洋洋流循環變慢；

The Amazon rainforest is weakening

亞馬遜雨林正在衰退，

and may start emitting carbon within 15 years.

十五年內可能開始排碳；

Half of the coral of the Great Barrier Reef has died.

大堡礁有半數珊瑚已經死亡；

West Antarctica may have crossed the tipping point already today.

現在，西南極冰層 可能早已跨越臨界點。

And now, the most solid of glaciers on earth, East Antarctica,

如今，全世界最堅固冰河， 東南極大陸，

parts of it are becoming unstable.

有部份也開始變得不穩定。

Nine out of the 15 big biophysical systems that regulate climate are now on the move,

十五大調節氣候的生物物理系統中，

showing worrying signs of decline

有九個正在變動，出現令人憂心的徵兆，

and potentially approaching tipping points.

顯示它們正在衰退並且逼近臨界點。

Tipping points bring three threats.

臨界點會帶來三項威脅：

First, sea level rise.

第一、海平面上升。

We can already expect up to one meter this century.

在本世紀已經可以預期會上升一公尺，

This will endanger the homes of 200 million people.

兩億人的家園將受到威脅。

But when we add the melting ice from Antarctica and Greenland

但如果再加上南極及格陵蘭的融冰，

into the equation,

則將可能上看兩公尺，

this might lead to a two meter rise.

而且不會停下來，只會越來越糟。

But it won't stop there, it will keep on getting worse.

其次，

Second, if our carbon stores like permafrost and forest

如果永凍層和森林等 所貯存的碳開始釋出，

flip to belching carbon,

穩定溫度的工作將會變得非常困難。

then this makes the job of stabilizing temperatures so much harder.

第三、這些系統 就像骨牌一樣彼此關聯，

And third, these systems are all linked like dominoes:

其中一個到了臨界點， 下一個也不遠了。

If you cross one tipping point, you lurch closer to others.

讓我們停一下，看看目前的狀況。

Let's stop for a moment and look at where we are.

我們的文明開創於穩定氣候、

The foundation of our civilization is a stable climate

生物多樣性豐富的環境之下。

and a rich diversity of life.

每件事物都是架構在這個基礎上。

Everything, I mean everything, is based on this.

文明社會在宜居帶之中興盛：

Civilization has thrived in a Goldilocks zone:

既不太熱、也不太冷。

not too hot, not too cold.

從上次冰河期以來， 我們維持了一萬年的宜居狀態。

This is what we have had for 10,000 years since we left the last ice age.

讓我們把時間軸拉長一點。

Let's zoom out a little here.

有三百萬年的時間，

Three million years --

溫度從沒打破攝氏 2 度的上限。

temperatures have never broken through the two degrees Celsius limit.

地球自行調節的範圍很窄：

Earth has self-regulated within a very narrow range

上升攝氏 2 度，進入暖和的間冰期；

of plus two degrees in a warm interglacial,

下降攝氏 4 度，則是大冰河時期。

minus four degrees, deep ice age.

現在，我們走的路徑

Now, we are following a path

可能讓我們在三代內

that would take us to a three to four degree world

面臨上升攝氏 3 到 4 度的世界。

in just three generations.

我們可能會倒轉氣候時鐘 到不只是一、兩百萬年前，

We would be rewinding the climate clock, not one million, not two million,

而是五百萬到一千萬年前。

but five to 10 million years.

我們正在朝高溫溫室地球前進。

We are drifting towards hot-house earth.

溫度每上升一度，

For each one degree rise,

就會有十億人被迫居住在 現今標準認定不適居的地方。

one billion people will be forced to live in conditions

這不是氣候危機，是星球危機。

that we today largely consider uninhabitable.

我怕的不是 2030 年 1 月 1 號 地球會突然墜落懸崖；

This is not a climate emergency, it is a planetary emergency.

我怕的是我們按下地球系統 不可挽回的按鈕。

My fear is not that Earth will fall over a cliff

接下來十年所發生的事，

on the 1st of January, 2030.

可能將會決定 我們交給子孫怎樣的地球。

My fear is that we press unstoppable buttons in the Earth system.

他們必然會驚慌失措。

What happens in the next 10 years

我們必須嚴陣以待，設法穩定地球。

will likely determine the state of the planet we hand over

將會有兩道防線引導我們 度過這場大變動：

for future generations.

第一道防線是科學。

Our children have every reason to be alarmed.

這裡有個新的永續地球方程式：

We need to get serious about stabilizing our planet.

「地球承載界線」加「全球公域」

Two frontiers will guide this transformation.

等於「地球管理」。

The first one is in science.

我們需要為人類找到一條安全走廊、

Here's a new equation for a sustainable planet:

讓全民成為整個星球的管理員，

planetary boundaries plus global commons

不為保護地球， 而是為全人類提供更好的未來。

equals planetary stewardship.

第二道防線是社會。

We need to a safe corridor for humanity

我們需要建構在福祉之上的 經濟新思維；

to allow us all to become stewards of the entire planet,

我們需要為全球公域、 公司行號以及所有城市

not to save the planet but to provide a good future for all people.

提供以科學為基礎的目標。

And the second frontier is in society.

首要任務就是在 2030 前 將全球碳排放量減半，

We need a new economic logic based on well-being.

並在 2050 以前達成淨零排放。

We are now in a position to provide science-based targets

這表示跟生活相關的所有系統 都必須是零碳排放：

for all global commons for all companies and cities in the world.

能源、產業、交通、建築。

First task, we need to cut global emissions by half by 2030

化石燃料的時代已經結束。

and reach net-zero by 2050 or sooner.

我們必須將原是碳排放源的農業

This means decarbonizing the big systems that run our lives:

轉型成碳貯存庫；

energy, industry, transport, buildings.

最緊急的是，我們必須保護海洋和土地，

The fossil fuel era is over.

其中的生態系統足以吸收 地球總排放量的一半。

We need to transform agriculture from a source of emissions

好消息是，我們可以做得到。

to a store of carbon,

我們有知識、科技，

and critically, we must protect our oceans and land,

我們也知道這樣做對社會、經濟都好。

the natural ecosystems that absorb half of our emissions.

當我們成功時，我們都可以 深吸一口清新的空氣、

The good news is, we can do this.

展開嶄新的健康生活、

We have the knowledge. We have the technology.

在宜居城市中從事健全的經濟活動。

We know it makes social and economic sense.

我們都在這場環繞太陽的共同旅途上。

And when we succeed, we can all take lungfuls of fresh air.

這裡是我們唯一的家。

We will be saying hello to healthy lifestyles

而我們的任務是： 守住我們子孫的未來。

and resilient economies in livable cities.

謝謝。

We are all on this journey around the sun together.

（燈開關切換聲）

This is our only home.

This is our mission: to protect our children's future.

Thank you.

(Lights click off)