Thank you very much.

當我還小的時候

When I was a boy,

父母時常會帶我去加州露營

my parents would sometimes take me camping in California.

沙灘、森林或沙漠等各種地方都有

We would camp in the beaches, in the forests, in the deserts.

有些人說沙漠沒有生命存在

Some people think the deserts are empty of life,

但我的父母要我去觀察 這些圍繞在四周的野生動物：

but my parents taught me to see the wildlife all around us,

隼、老鷹或陸龜等等

the hawks, the eagles, the tortoises.

有一次我們在紮營時

One time when we were setting up camp,

發現了一隻蠍子寶寶露出牠的螫刺

we found a baby scorpion with its stinger out,

當下我心想，真是太酷了

and I remember thinking how cool it was

怎麼會有這麼可愛 卻又這麼危險的東西

that something could be both so cute and also so dangerous.

大學畢業後，我搬到加州

After college, I moved to California,

著手進行一些環境相關的活動計畫

and I started working on a number of environmental campaigns.

參與了拯救全美 最後一座紅杉森林的工作

I got involved in helping to save the state's last ancient redwood forest

並阻止在沙漠中設置 放射性廢棄物的存放區

and blocking a proposed radioactive waste repository

剛滿 30 歲後不久

set for the desert.

我決定要窮盡一生

Shortly after I turned 30,

去解決氣候變遷的問題

I decided I wanted to dedicate a significant amount of my life

我擔心全球暖化

to solving climate change.

終會摧毀人們竭力 所保護的各種自然環境

I was worried that global warming would end up destroying

要解決這個問題 我認為在技術面很單純

many of the natural environments that people had worked so hard to protect.

在所有的屋頂裝上太陽能板 電動車的普及等

I thought the technical solutions were pretty straightforward -

最大的問題是在政策上

solar panels on every roof, electric car in the driveway -

因此我協助全國最大的勞工工會 以及最大的環保團體共同組織聯盟

that the main obstacles were political.

我們的提案是 3000 億美元的 再生能源投資計畫

And so I helped to organize a coalition

抱持的理念不只是預防氣候變遷

of the country's biggest labor unions and biggest environmental groups.

而且能在一個快速發展的高科技領域

Our proposal was for a 300-billion-dollar investment in renewables.

創造上百萬個工作機會

And the idea was not only would we prevent climate change,

在 2007 年，我們的努力有了成果

but we would also create millions of new jobs

當時的總統候選人 巴拉克·歐巴馬接受了我們的願景

in a very fast-growing high-tech sector.

在 2009 及 2015 年之間

Our efforts really paid off in 2007,

美國在再生能源等潔淨能源技術上 投資了 1500 億美元

when then-presidential candidate Barack Obama embraced our vision.

但一開始，我們就遇到一些問題

And between 2009 and 2015, the US invested 150 billion dollars

第一，屋頂太陽能板發電的 電力成本是太陽能發電廠的兩倍

in renewables and other kinds of clean tech.

且太陽能和風力發電廠

But right away, we started to encounter some problems.

都需要極大面積的土地 來設置太陽能板及風機

So first of all, the electricity from solar rooftops

並建置龐大的電力傳輸系統

ends up costing about twice as much as the electricity from solar farms.

以便將電力從鄉村送去都市

And both solar farms and wind farms

這些事情往往受到當地社區

require covering a pretty significant amount of land

以及保育生物學家的強烈抵制

with solar panels and wind turbines

他們擔心野生鳥類 及其他動物會受到迫害

and also building very big transmission lines

當時很多人在技術方面 努力解決這個問題

to bring all that electricity from the countryside into the city.

很大的一個挑戰是太陽能 及風力發電的間歇特性

Both of those things were often very strongly resisted by local communities,

它們一年只有 10% 到 30% 的時間在發電

as well as by conservation biologists

不過還是有一些提案

who were concerned about the impacts on wild-bird species and other animals.

像是把大壩當作一個巨大的電池

Now, there was a lot of other people

意思是當太陽露出、當風在吹時

working on technical solutions at the time.

馬達會把水打到高處儲存

One of the big challenges, of course, is the intermittency of solar and wind.

當你需要電力時 再這些水送入渦輪發電機組

They only generate electricity about 10 to 30 percent of the time

談到野生動物 問題似乎不那麼令人擔心

during most of year.

家貓每年會殺死數十億隻鳥

But some of the solutions being proposed

相比只有幾十萬隻鳥因風機而死

were to convert hydroelectric dams into gigantic batteries.

這時我在想

The idea was that when the sun was shining and the wind was blowing,

在大規模化太陽能及風力發電時

you would pump the water uphill, store it for later,

那些問題大部分都能以 未來的先進技術來解決

and then when you needed electricity, run it over the turbines.

但幾年過去了

In terms of wildlife, some of these problems

這些問題仍然存在，且越演越烈

just didn't seem like a significant concern.

加州非常致力於再生能源的發展

So when I learned that house cats kill billions of birds every year,

但將水壩改造為大型電池的計畫中

it put into perspective the hundreds of thousands of birds

落成的數量不多

that are killed by wind turbines.

有些只是地理位置上的問題

It basically seemed to me at the time

水壩必須有符合條件的 地形才能改造

that most, if not all, of the problems of scaling up solar and wind

即使能夠符合條件

could be solved through more technological innovation.

仍要很多的資金來實現

But as the years went by,

更不用說還有其他問題 像是灌溉等用水的需求

these problems persisted and, in many cases, grew worse.

或許最嚴重的問題是

So California is a state that's really committed to renewable energy,

加州河川和水庫的水

but we still haven't converted many of our hydroelectric dams

因為氣候變遷的緣故 越來越稀缺又不穩定

into big batteries.

為了不讓穩定性影響整體發電系統

Some of the problems are just geographic;

我們必須將太陽能發電廠 產出的電停止輸送到城市

it's just you have to have a very particular kind of formation

因為現在實在是太多了

to be able to do that,

或是花錢請亞歷桑納等鄰近的州 來消耗我們多餘的太陽能電力

and even in those cases,

否則會造成電網超載，無法供電

it's quite expensive to make those conversions.

說到鳥和家貓

Other challenges are just that there's other uses for water,

貓並不會傷害老鷹，但老鷹會殺害貓

like irrigation,

貓殺的是體型小且常見的 麻雀、松鴉和知更鳥

and maybe the most significant problem

這些鳥並不會有絕種的可能

is just that in California the water in our rivers and reservoirs

老鷹及大型鳥類

is growing increasingly scarce and unreliable

像是齒鷹、貓頭鷹和禿鷹 和其他遭受威脅及瀕臨絕種的物種

due to climate change.

才是風力發電機殺害的鳥類

In terms of this issue of reliability, as a consequence of it,

對這些大型鳥類來說 風機是最大的威脅之一

we've actually had to stop the electricity

近年設置風力機組之前

coming from the solar farms into the cities

我們從來沒有在天空上放這麼多東西

because there's just been too much of it at times.

而說到太陽能

Or we've been starting to pay our neighboring states, like Arizona,

建置太陽能發電廠就像是建置農場

to take that solar electricity.

必須騰出大片土地 清走其中的野生動物

The alternative is to suffer from blowouts of the grid.

這是加州最大的太陽能發電廠之一 照片拍到的只是它的 1/3 ──

And it turns out that when it comes to birds and cats -

艾文帕太陽能發電廠

cats don't kill eagles; eagles kill cats.

為了建置這發電廠

What cats kill are the small common sparrows and jays and robins,

他們必須清走整個區域的沙漠陸龜

birds that are not endangered and not at risk of going extinct.

直接把沙漠陸龜和小陸龜拖出洞穴

What do kill eagles and other big birds,

放到卡車中，運到圈養地

like this kite as well as owls and condors

許多就死在那裡

and other threatened and endangered species,

近期估計每年約有 6000 隻鳥被殺害

are wind turbines;

牠們在太陽能電廠的上方著火

in fact, they're one of the most significant threats

墜地而死

to those big bird species that we have.

隨著時間的過去，我漸漸意識到

We just haven't been introducing the airspace with many other objects

任何技術發展

like we have wind turbines over the last several years.

都不可能讓陽光穩定照射 讓風不斷地吹

And in terms of solar,

你只能把太陽能板變便宜

you know, building a solar farm is a lot like building any other kind of farm:

你只能讓風機變得更大

you have to clear the whole area of wildlife.

而陽光和風力就是這麼的沒效率

So this is a picture of one third of one of the biggest solar farms in California,

而為了產出足夠用的電力

called Ivanpah.

你必須使用大面積的土地

In order to build this,

換句話說，再生能源的 主要問題都不在技術面

they had to clear the whole area of desert tortoises,

是在自然環境面

literally pulling desert tortoises and their babies out of burrows,

要處理這些不穩定的問題

putting them on the back of pickup trucks, and transporting them to captivity,

以及這些環境的巨大衝擊

where many of them ended up dying.

明顯的要付出很大的經濟代價

And the current estimates are that about 6,000 birds are killed every year,

近幾年我們已經聽到太多

actually catching on fire above the solar farm

太陽能板及風力機組價格下降的消息

and plunging to their deaths.

但要把所有不穩定的 發電系統整合到電網上

Over time, it gradually struck me

花費仍然很可觀

that there was really no amount of technological innovation

從加州的情況即可見一斑

that was going to make the sun shine more regularly

在太陽能板和風力機組 價錢大幅下降之際

or wind blow more reliably;

我們所看見的反而是電費漲價幅度 比國內其他地區多了 5 倍

in fact, you could make solar panels cheaper,

這不是我們才有的問題

and you could make wind turbines bigger,

你可以看到相同的狀況發生在德國

but sunlight and wind are just really dilute fuels,

德國在太陽能、風力及其他 再生能源科技方面可說是世界龍頭

and in order to produce significant amounts of electricity,

在大力推動再生能源後 他們的電價上漲了 50%

you just have to cover a very large land mass with them.

你可能會想，對抗氣候變遷

In other words, all of the major problems with renewables aren't technical,

我們就必須在能源上花費更多

they're natural.

我以前也是這麼想的

Well, dealing with all of this unreliability

但看看法國的例子

and the big environmental impacts

以潔淨的零排放發電量來說

obviously comes at a pretty high economic cost.

法國是德國的兩倍

We've been hearing a lot

但電價幾乎是德國的一半

about how solar panels and wind turbines have come down in cost in recent years,

這是如何做到的？

but that cost has been significantly outweighed

你們可能已經猜出答案了

by just the challenges of integrating all of that unreliable power onto the grid.

法國有 75% 的電力來自核能

Just take, for instance, what's happened in California.

核能比再生能源可靠許多

At the period in which solar panels have come down in price

且每天 24 小時 每周 7 天都在發電

very significantly, same with wind,

一年有 90% 的時間在運轉

we've seen our electricity prices go up

我們看到這個現象在全球各地發生

five times more than the rest of the country.

舉例來說

And it's not unique to us.

有個為期 40 多年的自然實驗法研究

You can see the same phenomenon happened in Germany,

針對核能和太陽能的運用做比較

which is really the world's leader

顯示太陽能和風力發電 使用比核能稍高的成本

in solar, wind and other renewable technologies.

發電量卻只有核能的一半

Their prices increased 50 percent during their big renewable-energy push.

這意味著我們應該如何走下去？

Now you might think, well, dealing with climate change

我認爲截至目前最重大的發現是：

is just going to require that we all pay more for energy.

如果德國當時把 5800 億美元的經費 用以發展核能，而非再生能源

That's what I used to think.

現在他們 100% 的電力 以及所有交通運輸的能源

But consider the case of France.

都會是潔淨能源

France actually gets twice as much of its electricity

你們可能會問一個很合理的問題：

from clean zero-emission sources than does Germany,

核能安全嗎？ 你要如何處理核廢料？

and yet France pays almost half as much for its electricity.

這些都是非常合理的疑問

How can that be?

這裡有個超過 40 年的 科學研究結果

You might have already anticipated the answer.

最近一次的研究

France gets most of its electricity from nuclear power, about 75% in total.

是由英國的權威醫學雜誌 《刺胳針》進行

And nuclear just ends up being a lot more reliable,

他們發現核能是最安全的

generating power 24 hours a day, seven days a week,

這不難理解

for about 90% of the year.

世界衛生組織表示

We see this phenomenon show up at a global level.

一年約有 7 百萬人死於空氣污染

So, for example, there's been a natural experiment

核能不會造成空污

over the last 40 years,

氣候科學家詹姆士·漢森計算出

even more than that,

到目前為止，核能已經 拯救了近兩百萬條人命

in terms of the deployment of nuclear and the deployment of solar.

連風力發電也比核能更致命

You can see that at a little bit higher cost,

這張照片中是荷蘭的兩位維修工人

we got about half as much electricity from solar and wind

拍照後事隔不久，其中一位 為了躲避火燒而墜落身亡

than we did from nuclear.

另一位則是被大火吞沒

Well, what does all this mean for going forward?

對環境的影響呢？

I think one of the most significant findings to date is this one.

我認爲有一個非常簡單的方法能理解

Had Germany spent 580 billion dollars on nuclear instead of renewables,

鈾是核電廠的能量來源

it would already be getting a hundred percent of its electricity

它的能量密度非常高

from clean energy sources, and all of its transportation energy.

像這顆魔術方塊一樣大小的鈾

Now I think you might be wondering, and it's quite reasonable to ask:

即可產生你一生需要的所有能源

Is nuclear power safe? And what do you do with the waste?

結論是，大量發電 不需要這麼大面積的土地

Well, those are very reasonable questions.

你可以將我剛提到的 艾文帕太陽能電廠

Turns out that there's been scientific studies on this

和加州最後一座核電廠── 代亞布羅峽谷電廠作比較

going over 40 years.

為了產出相同的電力

This is just the most recent study,

太陽能電廠比核電廠 多花了 450 倍的土地面積

that was done by the prestigious British medical journal Lancet,

你需要增加 17 座 像艾文帕的太陽能電廠

finds that nuclear power is the safest.

發電量才會 與代亞布羅峽谷核電廠相同

It's easy to understand why.

此外，太陽能還會降低發電的可靠性

According to the WHO,

如果從原料採集、廢料 和材料吞吐量的角度來看呢？

about 7 million people die annually from air pollution.

這也有被充分的研究過

And nuclear plants don't emit that.

結果是

As a result, the climate scientist James Hansen looked at it.

太陽能板所需的材料 比核電廠多出 17 倍

He calculated that nuclear power has already saved

這些材料包含 水泥、玻璃、混凝土、金屬

almost two million lives to date.

所有核電廠所需的燃料也包含在內

It turns out that even wind energy is more deadly than nuclear.

到頭來，經過整個發電流程

This is a photograph taken of two maintenance workers

核電所產出的廢棄物並不多

in the Netherlands,

這個房間可以容得下 瑞士核電計畫產出的所有廢棄物

shortly before one of them fell to his death to avoid the fire,

核廢料是核能發電的唯一廢棄物

and the other one was engulfed in flames.

它被安全地保存 沒有額外的社會成本

Now, what about environmental impact?

其他方式所產生的電力

I think a really easy way to think about it

排放出的廢棄物都進入了大自然

is that uranium fuel, which is what we used to power nuclear plants,

這些可能是污染物或固體廢棄物

is just really energy dense.

我們以為太陽能發電很乾淨

About the same amount of uranium as this Rubik's Cube

但事實是我們沒有任何計劃

can power all of the energy you need in your entire life.

來處理 20 或 25 年後的 廢棄太陽能板

As a consequence,

許多專家都非常擔心太陽能板 會連同電子產品廢棄物

you just don't need that much land

一起被運往貧窮的 非洲或亞洲國家進行拆解

in order to produce a significant amount of electricity.

工作人員將接觸到 大量的危害性有毒元素

Here you can compare the solar farm I just described, Ivanpah,

包含鉛、鎘和鉻

to California's last nuclear plant,

因為它們是元素，毒性永遠不會降解

Diablo Canyon.

我想我們心裡都知道

It takes 450 times more land to generate the same amount of electricity

核能真是個很強大的能源

as it does from nuclear.

太陽光很分散又微弱

You would need 17 more solar farms like Ivanpah

這也就是為什麼 我們需要有這麼大的面積

in order to generate the same output as Diablo Canyon,

來收集太陽光和風

and of course, it would then be unreliable.

最近的新版《銀翼殺手》科幻片中

Well, what about the mining and the waste and the material throughput.

一開場就是一個灰暗的後末日景象

This has been studied pretty closely as well,

加州的沙漠完全被太陽能板覆蓋

and it just turns out

沒有人會對這一幕感到驚訝

that solar panels require 17 times more materials than nuclear plants do,

我想，這一切讓我們 不禁要提出一個令人不安的問題：

in the form of cement, glass, concrete, steel -

為了拯救氣候，我們要毀掉環境嗎？

and that includes all the fuel used for those nuclear plants.

有趣的是，過去幾百年的時間

The consequence is that what comes out at the end, since its material throughput,

人類其實試著要淘汰 所謂的高物質密度燃料

is just not a lot of waste from nuclear.

而轉移到高能量密度的燃料

All of the waste from the Swiss nuclear program fits into this room.

比如說，從木材、動物乾糞 轉換到煤、石油、天然氣、鈾

Nuclear waste is actually the only waste from electricity production

這是自古以來的現象

that's safely contained and internalized.

有些貧窮國家目前 才逐漸在淘汰木材、乾糞燃料

Every other way of making electricity

大致來說，這是件好事

emits that waste into the natural environment,

當你停止使用木材作為燃料來源

either as pollution or as material waste.

森林有機會重新生長 野生動物才得以回歸大自然

We tend to think of solar panels as clean,

當你停止在家裡燒木材

but the truth is that there is no plan

你不需要再吸入這些有毒氣體

to deal with solar panels at the end of their 20 or 25-year life.

當你開始使用煤、石油、天然氣和鈾 作為能源的主要來源

A lot of experts are actually very concerned that solar panels

徹底消除空氣汙染的 潛在契機就會出現

are just going to be shipped to poor countries in Africa or Asia,

核能有個問題

with the rest of our electronic-waste stream,

大部分人都欣然接受 從污染性能源轉換成潔淨能源

to be disassembled,

以及從低能量密度 轉換成高能量密度能源

often exposing people to really high level of toxic elements,