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譯者: 耀祖 施
審譯者: Helen Chang
00:06
Historically, most cars have run
on gasoline,
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歷史上大多車子以汽油作燃料,
00:10
but that doesn’t have to be
the case in the future:
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但未來可不一定也是這樣:
00:12
other liquid fuels and electricity
can also power cars.
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其他液態燃料和電
也能作為車子的動能。
00:16
So what are the differences
between these options?
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那麼這些燃料有哪裡不同?
00:19
And which one’s best?
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哪一種又是最好的呢?
00:21
Gasoline is refined from crude oil,
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汽油是由原油所精煉,
00:24
a fossil fuel extracted
from deep underground.
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是從地底深處所萃取的石化燃料。
00:27
The energy in gasoline comes from a class
of molecules called hydrocarbons.
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汽油的能量來自碳氫化合物。
00:32
There are hundreds of different
hydrocarbons in crude oil,
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原油中有上百種不同的碳氫化合物,
00:35
and different ones are used
to make gasoline and diesel—
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製作汽油和柴油所用的就不同,
00:39
which is why you can't use
them interchangeably.
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這就是為什麼它們不能互換使用。
00:42
Fuels derived from crude oil
are extremely energy dense,
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原油衍生的燃料能量極度密集,
00:47
bringing a lot of bang for your buck.
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能夠花少錢得大效果。
00:50
Unfortunately, they have many drawbacks.
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不幸的,這些燃料有很多缺點。
00:52
Oil spills cause environmental damage
and cost billions of dollars to clean up.
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漏油傷害環境,清潔成本高達數十億。
00:57
Air pollution from burning
fossil fuels like these
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燃燒此等石化燃料造成的空氣汙染
01:00
kills 4.5 million people each year.
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每年導致 450 萬人死亡。
01:04
And transportation accounts for 16%
of global greenhouse gas emissions,
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交通所排放
就佔全球溫室氣體的 16% ,
01:09
almost half of which comes
from passenger cars burning fossil fuels.
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近乎一半來自客車燃燒石化燃料。
01:13
These emissions warm the planet
and make weather more extreme.
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這些排放使地球暖化
並造成更加極端的氣候
01:17
In the U.S. alone,
storms caused by climate change
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光是在美國,氣候變遷所帶來的風暴
01:20
caused $500 billion of damage
in the last five years.
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在過去五年就造成 5000 億美元損失。
01:25
So while gas is efficient,
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因此,即便汽油使用上很有效率,
01:27
something so destructive
can't be the best fuel.
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但如此具破壞性不會是最好的燃料。
01:31
The most common alternative
is electricity.
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最常見的替代品是電力。
01:33
Electric cars use a battery pack
and electric motor
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電動車使用電池組和電動馬達
01:37
instead of the internal combustion engine
found in gas-powered cars,
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而非汽油車用的內燃機,
01:41
and must be charged at charging stations.
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且只能在充電站充電。
01:44
With the right power infrastructure, they
can be as efficient as gas-powered cars.
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只要有適當充電建設,
電動車也可以跟燃油車一樣有效率。
01:49
If powered by electricity generated
without fossil fuels,
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若是不靠石化燃料產生的電力所驅動,
01:53
they can avoid greenhouse gas emissions
entirely.
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則可以完全免除溫室氣體的排放。
01:56
They’re more expensive
than gas-powered cars,
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電動車比汽油車更貴,
01:59
but the cost difference has been
shrinking rapidly since 2010.
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但 2010 以來
兩者的成本差異已迅速縮小。
02:03
The other alternatives to gasoline
are other liquid fuels.
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汽油的其他替代品是其他液態燃料。
02:07
Many of these can be shipped and stored
using the same infrastructure as gasoline,
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許多液態燃料可透過汽油用基礎設施
運送並且儲存,
02:11
and used in the same cars.
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並用於相同的車子。
02:13
They can also be carbon-neutral
if they’re made using carbon dioxide
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這些也可能是碳中和的燃料,
只要這些燃料是用
大氣中的二氧化碳製造的,
02:18
from the atmosphere—
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02:19
meaning when we burn them, we release that
same carbon dioxide back into the air,
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也就是當這些燃料燃燒時,
便將原本的二氧化碳釋放回空氣中,
02:24
and don't add to overall emissions.
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整體排放不會增加。
02:28
One approach to carbon-neutral fuel
is to capture carbon dioxide
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捕捉大氣中的二氧化碳,將其中的碳
02:31
from the atmosphere and combine its carbon
with the hydrogen in water.
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與水中的氫結合是碳中和燃料的途徑。
02:36
This creates hydrocarbons,
the source of energy in fossil fuels—
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這創造出碳氫化合物,
即石化燃料的能量來源,
02:40
but without any emissions if the fuels
are made using clean electricity.
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只要用乾淨的電力產生燃料
就不會有任何排放。
02:45
These fuels take up more space
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相較於汽油等量的能源,
02:47
than an energetically equivalent
amount of gasoline—
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這些燃料占用更多空間,
02:50
an obstacle to using them in cars.
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是用於車上的一個障礙。
02:53
Another approach is to make carbon-neutral
fuels from plants,
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另一個途徑是以植物製造碳中和燃料,
02:57
which sequester carbon from the air
through photosynthesis.
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透過光合作用隔離空氣中的碳。
03:01
But growing the plants also has
to be carbon neutral—
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但栽種植物也必須以碳中和的方式,
03:04
which rules out many crops
that require fertilizer,
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這排除了許多需要使用
化學肥料的農作物,
03:07
a big contributor
to greenhouse gas emissions.
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會排放大量溫室氣體化肥的農作物。
03:10
So the next generation of these fuels
must be made from either plant waste
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所以這些下個世代的燃料
一定是以植物廢棄
03:15
or plants that don't require
fertilizer to grow.
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或不需化肥栽種的植物來製作。
03:19
Biofuels can be about as efficient
as gasoline, though not all are.
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生化燃料可以跟汽油一樣有效率,
雖然不是所有都是。
03:24
For a fuel to be the best option,
people have to be able to afford it.
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若要成為最好的燃料選項
一定要是人們可負擔的。
03:28
Unfortunately, the high upfront costs
of implementing new technologies
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很不幸,採用新技術高額的前置成本,
03:33
and heavy subsidies for the producers
of fossil fuels,
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以及石化燃料生產者的高額補貼,
03:35
mean that almost every green technology
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表示幾乎每項綠色科技
03:38
is more expensive than
its fossil-fuel-based cousin.
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都比石化類的相似科技還要更貴。
03:42
This cost difference is known
as a green premium.
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這種成本上的差異也就是綠色溢價。
03:46
Governments have already started
subsidizing electric vehicles
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政府已開始提供電動車補貼
03:49
to help make up the difference.
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幫助彌補這種差異。
03:51
In some places, depending
on the costs of electricity and gas,
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在某些地方,根據電力和汽油的成本
03:54
electric cars can already
be cheaper overall,
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使用電動車整體上會更加便宜,
03:57
despite the higher cost of the car.
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即便電動車本身要價不斐。
04:00
The other alternatives are trickier,
for now—
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目前,其他替代品使用上更困難,
04:03
zero-carbon liquid fuels can be
double the price of gasoline or more.
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零碳液態燃料要價是汽油兩倍以上。
04:08
Innovators are doing everything
they can to bring green premiums down,
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創新者盡其所能使綠色溢價下降,
04:12
because in the end, the best fuel
will be both affordable for consumers
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因為最終,最好的燃料
必須是消費者可負擔
04:17
and sustainable for our planet.
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又可以在我們的星球上永續使用的。
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