Whatever happened to acid rain? - Joseph Goffman

2,536,302 views ・ 2021-04-13

TED-Ed


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翻译人员: Lh T 校对人员: Helen Chang
00:07
In 1963, scientists studying Hubbard Brook Experimental Forest in New Hampshire
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1963年,在汉普郡哈伯德 布鲁克实验林学习的科学家们
00:13
made a shocking discovery.
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有了一个惊人的发现
00:15
Their most recent rainfall samples were nearly 100 times more acidic than usual.
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他们最近雨水样本的酸度 几乎是往常酸度的100倍
00:21
At these levels, additional downpours of acid rain
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在这样的酸度水平下,更多的雨量
00:25
would destroy the region’s marine and arboreal ecosystems
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将在几十年内摧毁地区的 海洋和林木生态系统
00:29
in a matter of decades.
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00:30
Urgently sharing their findings with fellow researchers,
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迫切地想与其他研究员 分享他们的这个发现
00:34
they were determined to answer two questions:
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他们决定回答两个问题:
00:37
what was causing this deadly rainfall? And what could be done to stop it?
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是什么使雨水变得致命? 我们能做什么去阻止它?
00:43
Rain is never just composed of water.
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雨水不止是由水组成
00:46
Chemicals and particulates in the atmosphere can be found in every drop,
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每滴雨水中都发现 含有大气中的化学物质和微粒
00:51
and some compounds— like carbon dioxide—
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和某些化合物,像二氧化碳
00:54
make even regular rainfall slightly acidic.
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使正常的雨水有些微酸性
00:57
But this pales in comparison to the powerful acids produced
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但和水与氮的氧化物 或与二氧化硫形成的强酸时相比
01:01
when water interacts with oxides of nitrogen or sulfur dioxide.
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这酸度就显得相形见绌了
01:07
On the pH scale which measures acidity,
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在用pH尺度衡量酸度时
01:10
each whole number is 10 times more acidic than the one above it.
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每个整数比后一个整数酸10倍
01:15
And where normal rain has a pH of roughly 5.4,
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正常雨水的pH大约是5.4
01:19
rain that’s interacted with these gases can rank as low as 3.7.
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雨水若是与这些气体作用 将会使此等级降至3.7
01:24
Oxides of nitrogen and sulfur dioxide can appear naturally
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含氮氧化物和二氧化硫
能在火山爆发和雷击时 作为产生的天然副产物短暂在世停留
01:29
as a short-lived byproduct of volcanic eruptions or lightning strikes.
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01:34
But power plants, refineries, and vehicles that use fossil fuels
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但是发电厂,提炼厂 和使用化石燃料的交通工具
01:38
consistently pump large quantities into the air.
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持续地将这些氧化物泵到空气中
01:43
These dangerous gases travel with the wind
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这些有害气体随风从源头地
01:46
spreading hundreds of kilometers from the pollution’s source.
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流动几百千米扩散到各地
01:49
Acting like roaming clouds of destruction,
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就像在漫游的有毁灭性的风
01:52
their presence dramatically increases the acidity of local precipitation,
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它们的到来使当地雨水的酸度 有了显著的升高
01:57
creating acid rain, acid snow, and acid fog.
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就产生了酸雨、酸性雪、酸雾
02:02
These all acidify lakes and streams, kill crops and forests,
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这些酸性湖泊和溪流毁掉了作物和林木
02:07
and damage soil to inhibit future growth.
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损害土壤,抑制了植物以后的生长
02:10
Over time, acid rain can even corrode human structures made of stone or metal.
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随着时间的推移,酸雨也会腐蚀 人类用石头和金属所造的建筑
02:17
By the 1970s, scientists in North America and Europe classified acid rain
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在二十世纪70年代 北美和欧洲的科学家
将酸雨视为排在首位的环境威胁
02:23
as a major environmental threat.
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02:25
But despite clear evidence tying the problem to air pollution,
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但是即使空气污染 和有害气体的排放有明显的联系
02:29
companies denied responsibility and cast doubt on the research.
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企业也否认他们应该承担责任 并对此项调查提出了质疑
02:33
In the United States, corporations lobbied against regulating pollution,
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在美国,企业游说反对控制污染
02:38
and convinced politicians that such policies
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说服政客,倘若实行这种政策
02:41
would raise energy costs and threaten jobs.
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将会耗费更多的能源资金且威胁到就业
02:44
These obstacles led the government to delay changes,
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这些障碍让政府推迟了改变
02:47
and mandate further research into the issue.
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下令让此项目做进一步的研究
02:50
But after a decade of mounting concern, Congress finally took action.
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但在十年后关注度越来越多以后 国会终于采取了行动
02:56
Since the bulk of sulfur dioxide emissions came from power plants,
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因为大部分二氧化硫是 从发电厂排放出来的
03:00
the government set a limit on the total amount of it
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政府限制其电力部门每年容许的总排量
03:03
the electric power sector could emit each year.
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03:06
Then, they divided the permitted emissions into a fixed number of “allowances”
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然后,他们将允许的排放量 分成固定数量的配额
03:12
distributed to each power plant.
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分配给每个发电厂
03:14
A plant could then choose to emit as much sulfur dioxide as they were allowed,
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工厂可以在允许范围内 选择排放尽可能多的二氧化硫
03:19
or reduce their emissions and sell their unused allowances to other power plants.
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或者缩小排放量,并把他们 未使用的配额卖给其他发电厂
03:25
This system, known as “cap and trade,”
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这个体制名为”总量管制与交易”
03:29
offered power plants the economic flexibility to keep costs low
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保障了当严格的污染限制条令下发时
03:33
while strictly limiting pollution.
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发电厂保持低成本的灵活经济性
03:35
Many critics called these allowances licenses to pollute,
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许多批评人士称这些为 免税额污染许可证
03:39
or said the government was selling clean air.
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或者说政府卖干净的空气
03:42
But since the cap was set to lower five years into the program,
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但由于上限被设定为 五年后还要降得更低
03:46
it forced every utility company to reduce emissions in the long term.
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它迫使所有公用事业公司长期削减排放
03:51
Some plants added desulfurizing scrubbers to their smokestacks,
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一些工厂在他们的烟囱增加了脱硫机
03:55
or switched to low-sulfur coal and natural gas.
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或者改用低硫煤和天然气
03:59
Oxides of nitrogen emissions were also reduced
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用相对低成本的技术 也减少了氮氧化物的排放
04:02
with relatively low-cost technologies.
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04:05
These advances allowed the power sector to grow
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这些进步使电力部门得以发展
04:08
while the cap kept pollution under control.
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而上限使污染得到控制
04:11
By 1985, Canada and the European Union adopted their own solutions,
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到1985年,加拿大和欧盟 采用了各自的解决方案
04:16
and international treaties began circulating
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国际条约开始相继使用
04:19
to reduce air pollution worldwide.
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为了减少全球大气污染
04:23
Today, this science-driven economic policy has largely eliminated acid rain
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如今,这种以科学为导向的经济政策 已在很大程度上消除了酸雨
04:28
across the United States and Canada.
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涵盖整个美国和加拿大
04:30
And while many ecosystems still need time to recover,
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尽管许多生态系统仍然需要时间来恢复
04:33
scientists have sped up the restoration of other areas
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科学家们通过引入 被酸雨杀死的必要生物体
04:37
by reintroducing essential organisms killed off by acid rain.
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来加快修复其他地区的进程
04:42
Some countries, like Russia, India, and China
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有些国家,像俄罗斯、印度和中国
04:45
still rely heavily on high-sulfur coal
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仍然极度依赖高硫煤
04:48
and continue to struggle with the environmental consequences.
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将继续与环境带来的后果作斗争
04:52
However, acid rain’s relatively quick journey from major threat to minor issue
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然而,酸雨相对迅速地 从重大威胁变成了次要问题
04:57
is rightly celebrated as a victory for policies that protect the environment.
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是环境保护政策的胜利
05:02
Cap and trade can’t solve every environmental problem.
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”总量管制与交易” 不能解决每个环境问题
05:05
But by using scientific consensus to guide policy,
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但通过运用科学共识指导政策
05:09
adopting efficient technology,
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运用有效的科技手段
05:11
and being unafraid to impose reasonable costs for pollution,
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不惧因为污染施加的合理成本
05:15
countries can stop a growing storm of destruction before it’s too late.
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国家们还能在不算晚的日子 制止一场正在壮大的毁灭性风暴
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