Ten years is a long time for us humans on earth. Ten turns around the sun.
十年对我们地球上的人类来说很长，相当于绕太阳公转十圈。
When I was on the TED stage a decade ago, I talked about planetary boundaries that keep our planet in a state that allowed humanity to prosper.
十年前，当我站在TED讲台上时，我谈到了地球上的边界，它们能使我们的地球保持在一种让人类繁荣的状态。
The main point is that once you transgress one, the risks start multiplying.
重点是一旦你越界，风险就会开始倍增。
The planetary boundaries are all deeply connected, but climate, alongside biodiversity, are core boundaries. They impact on all others.
地球的边界都是紧密相连的，但是气候和生物多样性是边界之核心，它们会影响到其余一切。
Back then we really thought we had more time.
当时，我们真的以为我们有更多的时间。
The warning lights were on, absolutely, but no unstoppable change had been triggered.
警示灯的确是亮着，但没有引发不可阻挡的变化。
Since my talk, we have increasing evidence that we are rapidly moving away from the safe operating space for humanity on earth.
自从我的演讲以来，我们有越来越多的证据表明，我们正迅速远离地球上人类的安全活动空间。
Climate has reached a global crisis point.
气候已经到了全球危机的地步。
We have now had 10 years of record-breaking climate extremes:
十年来，极端气候的纪录不断被打破：
fires blaze in Australia, Siberia, California and the Amazon, floods in China, Bangladesh and India.
肆虐于澳大利亚、西伯利亚、加利福尼亚和亚马逊的大火，以及中国、孟加拉国和印度的洪水。
We're now enduring heat waves across the entire northern hemisphere.
我们现在正经历着席卷整个北半球的热浪。
We risk crossing tipping points that shift the planet from being our best resilient friend, dampening our impacts,
我们冒着跨越临界点的风险，将地球从我们最好的朋友，它能抵御冲击，
to start working against us, amplifying the heat.
转变为开始与我们作对的朋友，它加剧升温。
For the first time, we are forced to consider the real risk of destabilizing the entire planet. Our children can see this.
我们第一次迫不得已去考虑破坏整个地球稳定的真正风险。我们的孩子可以看到这一点。
They are walking out of school to demand action, looking with disbelief at our inability to deviate away from potentially catastrophic risks.
他们罢课要求采取行动，怀疑我们无法摆脱潜在的灾难性风险。
The next 10 years, to 2030, must see the most profound transformation the world has ever known.
直至2030年的未来十年，必须发生世界有史以来最深刻的变革。
This is our mission. This is the countdown.
这是我们的使命。这就是倒计时。
When my scientific colleagues summarized, about a decade ago, for the first time, the state of knowledge on climate tipping points,
大约十年前，当我的科学家同事第一次总结关于气候临界点的知识状况时，
just one place had strong evidence that it was on a serious downward spiral.
只有一个地方有确凿证据表明气候正处于严重的下滑阶段。
Arctic sea ice. Other tipping points were long way off -- 50 or 100 turns around the sun.
北极海冰。我们离其他的临界点还很远，至少还要等公绕太阳转50或100圈。
Just last year we revisited these systems, and I got the shock of my career.
就在去年，我们重新查看了这些系统，我受到了我职业生涯最大的冲击。
We are only a few decades away from an Arctic without sea ice in summer.
我们离夏天没有海冰的北极只有几十年的路程。
In Siberia, permafrost is now thawing at dramatic scales.
在西伯利亚，永久冻土正以惊人的规模消融。
Greenland is losing trillions of tons of ice and may be approaching a tipping point.
格陵兰岛正在失去数万亿吨的冰，并可能接近临界点。
The great forests of the North are burning with plumes of smoke the size of Europe.
北方的大森林燃烧着相当于欧洲大小的烟雾。
The Atlantic ocean circulation is slowing. The Amazon rainforest is weakening and may start emitting carbon within 15 years.
大西洋环流正在放缓。亚马逊雨林正在减弱，可能在15年内开始排放碳。
Half of the coral of the Great Barrier Reef has died.
大堡礁一半的珊瑚已经死亡了。
West Antarctica may have crossed the tipping point already today.
今天，南极洲西部可能已经越过了一个临界点。
And now, the most solid of glaciers on earth, East Antarctica, parts of it are becoming unstable.
现在，地球上最坚固的冰川南极洲东部的部分冰川正在变得不稳定。

Nine out of the 15 big biophysical systems that regulate climate are now on the move,
调节气候的15大生物物理系统中有9个现在正在移动，
showing worrying signs of decline and potentially approaching tipping points. Tipping points bring three threats.
显示出令人担忧的下降迹象，并可能接近临界点。临界点会带来三个威胁。
First, sea level rise. We can already expect up to one meter this century. This will endanger the homes of 200 million people.
第一，海平面上升。本世纪我们已经可以预计到一米。这将危及两亿人的家园。
But when we add the melting ice from Antarctica and Greenland into the equation, this might lead to a two meter rise.
但是，当我们把南极洲和格陵兰岛融化的冰加入方程时，这可能会导致两米的上升。
But it won't stop there, it will keep on getting worse.
但不会就此停止，它会继续恶化。
Second, if our carbon stores like permafrost and forest flip to belching carbon, then this makes the job of stabilizing temperatures so much harder.
第二，如果我们的碳储存，如永久冻土和森林转变为排放碳，那么稳定气温的工作就会变得更加困难。
And third, these systems are all linked like dominoes: If you cross one tipping point, you lurch closer to others.
第三，这些系统都像多米诺骨牌一样息息相关：如果你越过了一个临界点，你就会向其他临界点靠拢。
Let's stop for a moment and look at where we are.
让我们停一会儿，看看我们在哪里。
The foundation of our civilization is a stable climate and a rich diversity of life.
我们文明的基础是稳定的气候和丰富多样的生活。
Everything, I mean everything, is based on this. Civilization has thrived in a Goldilocks zone: not too hot, not too cold.
一切，所有一切都是基于此。文明在一个宜居带蓬勃发展，不能太热，也不能太冷。
This is what we have had for 10,000 years since we left the last ice age. Let's zoom out a little here.
这就是我们距离上一个冰河世纪以来的一万年。让我们把这里放大一点。
Three million years -- temperatures have never broken through the two degrees Celsius limit.
300万年来，气温从未突破两摄氏度的极限。
Earth has self-regulated within a very narrow range of plus two degrees in a warm interglacial, minus four degrees, deep ice age.
地球在一个非常狭窄的范围内进行自我调节，即在温暖的间冰期加两度，深冰期减四度。
Now, we are following a path that would take us to a three to four degree world in just three generations.
而今，我们正沿着一条道路前进，这条道路将在仅三代人的时间里把我们带到一个三到四度的世界。
We would be rewinding the climate clock, not one million, not two million, but five to 10 million years. We are drifting towards hot-house earth.
我们倒转的气候时钟，不是100万年，不是200万年，而是500万到1000万年。我们正朝着温室地球漂移。
For each one degree rise, one billion people will be forced to live in conditions that we today largely consider uninhabitable.
每上升一度，就会有十亿人被迫生活在我们今天认为不适宜居住的环境中。
This is not a climate emergency, it is a planetary emergency.
这不是气候紧急情况。这是一个全球性的紧急事件。
My fear is not that Earth will fall over a cliff on the 1st of January, 2030.
我担心的不是2030年1月1日地球会掉下悬崖。
My fear is that we press unstoppable buttons in the Earth system.
我担心的是我们按下了地球系统中不可停止的按钮。
What happens in the next 10 years will likely determine the state of the planet we hand over for future generations.
未来十年发生的事情可能会决定我们留给后代的地球状况。
Our children have every reason to be alarmed. We need to get serious about stabilizing our planet.
我们的孩子完全有理由感到震惊。我们需要将稳定地球的使命认真对待。
Two frontiers will guide this transformation. The first one is in science.
两条战线将引领这一转变。第一条是在于科学。
Here's a new equation for a sustainable planet: planetary boundaries plus global commons equals planetary stewardship.
这里有一个可持续地球的新等式：地球边界，加上全球公域，等于地球管理。
We need to a safe corridor for humanity to allow us all to become stewards of the entire planet,
我们需要为人类建立一个安全的走廊，让我们都成为整个地球的管理者，
not to save the planet but to provide a good future for all people.
不是为了拯救地球，而是为所有人提供一个美好的未来。
And the second frontier is in society. We need a new economic logic based on well-being.
第二条战线是在社会。我们需要一种基于福祉的新经济逻辑。
We are now in a position to provide science-based targets for all global commons for all companies and cities in the world.
我们现在有能力为全球，为所有企业和城市提供基于科学的目标。
First task, we need to cut global emissions by half by 2030 and reach net-zero by 2050 or sooner.
第一项任务，我们需要在2030年前将全球排放量减半，在2050年或更早达到净零排放。
This means decarbonizing the big systems that run our lives: energy, industry, transport, buildings.
这意味着让我们生活、能源、工业、交通和建筑的大系统去碳化。
The fossil fuel era is over. We need to transform agriculture from a source of emissions to a store of carbon,
化石燃料时代已经结束。我们需要将农业从排放源转变为碳储存源，
and critically, we must protect our oceans and land, the natural ecosystems that absorb half of our emissions.
关键是我们必须保护我们的海洋和土地，它们是能吸收我们一半排放量的自然生态系统。
The good news is, we can do this. We have the knowledge. We have the technology.
好消息是我们可以做到。我们有知识，我们有技术。
We know it makes social and economic sense. And when we succeed, we can all take lungfuls of fresh air.
我们知道它有社会和经济意义。当我们成功时，我们都能呼吸到新鲜的空气。
We will be saying hello to healthy lifestyles and resilient economies in livable cities.
我们将向宜居城市的健康生活方式和弹性经济招手。
We are all on this journey around the sun together. This is our only home.
我们都在一起绕着太阳旅行。这是我们唯一的家。
This is our mission: to protect our children's future. Thank you.
这是我们保护孩子未来的使命。谢谢大家。