What Seaweed and Cow Burps Have to Do with Climate Change | Ermias Kebreab | TED Countdown

翻译人员: Yip Yan Yeung 校对人员: Helen Chang

Pasture is the single largest type of land

牧草地是当今地球上

on the surface of the Earth today,

覆盖面最大的土地类型，

thanks to our taste for meat and dairy.

多亏了我们对肉类 和奶制品的热爱。

Just over a quarter of all land is used for livestock.

超过四分之一的 土地总量用于牲畜，

That's more than forests or farm fields or anything else.

超过了森林、农田 或其他类型的土地。

Most of that land is best for ruminants,

大部分牧草地 对反刍动物非常合适，

such as cows,

比如牛，

that can digest high-fiber feed such as grass and straw.

可以消化高纤维饲料 如牧草和稻草。

However, the process by which grass and fiber is broken up

然而，草和纤维在

in the stomachs of cows and other grazing ruminants

牛和其他食草反刍动物的 胃里的分解过程

has a byproduct, methane,

会生产出一种副产品——甲烷，

a potent greenhouse gas.

一种强力的温室气体。

Despite what you might have heard about methane and cows,

你也许听过甲烷和牛，

most of the methane is actually burped out,

但是大部分甲烷其实是 从嘴里喷出来的，

not through the back end.

不是从屁股。

(Laughter)

（笑声）

And that represents about two billion tons

这相当于每年 20 亿吨的

of carbon dioxide equivalent per year,

二氧化碳量，

or more than four percent of our annual global greenhouse gas emissions.

或超过每年全球温室气体 排放的 4% 。

We have a methane problem from cows.

我们遇到了牛的甲烷问题。

So how can you reduce these methane burps?

那么如何减少这些甲烷嗝呢？

My colleagues and I may have found a solution.

我和我的同事 可能发现了一个答案。

Seaweed!

海草！

Let me explain.

让我来解释。

A couple of years ago,

几年前，

an article was published by Rob Kinley and colleagues

罗伯·金利（Rob Kinley） 和他的同事

that showed almost complete elimination of methane

发表了一篇文章，表示 在实验室中，切碎的草里加入海草

when seaweed was added to chopped grass in the lab.

几乎可以完全消灭甲烷。

Great.

太好了。

But as an agricultural researcher,

但是作为一个农业研究者，

I know lots of additives work well in the lab,

我知道很多添加剂 在实验室里效果很好，

but not in real animals.

但是在真实动物 身上就不是那回事。

But there was something different about seaweed

但是海草

and the way in which it reduced methane.

和它减少甲烷的方式有点不同。

So we thought we should test this in live animals.

所以我们在想是不是应该 在活体动物上试验一下。

In collaboration with Joan Salwen,

我们与琼·萨尔文合作，

an entrepreneur,

她是一位企业家，

and colleagues from James Cook University and CSIRO,

一位来自詹姆斯·库克大学

和澳大利亚联邦科学与工业 研究组织（CSIRO）的同事，

we decided to conduct a small experiment

我们开展了一项小型试验

to determine the amount of seaweed we might need to use.

决定我们可能需要用多少海草。

This was the first ever experiment in dairy cattle,

这是首次试验于奶牛，

and we had no idea how much to give them.

我们不知道应该喂它们多少量。

So we started with about 60 grams per day,

所以我们从每天 约 60 克开始，

going up to 250 grams.

增至 250 克。

Mind you, this was mixed in with 25 kilograms of their feed.

值得注意的是，海草是 被混在 25 千克的饲料中。

One of the graduate students I work with, Breanna Roque,

与我合作的一个研究生，

布里安娜·罗克 （Breanna Roque），

trapped their methane burps.

收集了它们的甲烷嗝。

(Laughter)

（笑声）

In that first experiment,

在第一次试验中，

the emissions were reduced by up to 67 percent.

排放量减少了高达 67% 。

(Applause)

（掌声）

And I thought at first,

刚开始我还以为

the equipment must have malfunctioned, but it was real.

设备坏掉了，但是这是真的。

But we are left with more questions than answers.

但是留下了更多的疑问而不是答案。

Would the microbes in the gut get used to it

肠胃中的微生物会不会 随着时间的推移而习惯于海草，

and start producing methane over time?

又开始生产甲烷？

Would the seaweed be stable over a long period of time in storage?

海草在长时间存储后 会不会保持稳定？

Would the taste be affected and the cows turn up their noses?

味道会不会受影响，牛不吃了？

Or would the seaweed affect the cows's health or milk production?

或者海草会不会影响 牛的健康或者产奶？

So we teamed up again to conduct another trial.

所以我们又合作做了另一个试验。

Over a five-month period,

在五个月期间，

we saw the seaweed that was harvested three years prior

我们发现三年前收割的海草

reduce emissions by over 80 percent.

可以减少超过 80% 的排放量。

(Applause)

（掌声）

Our colleagues in Australia,

我们在澳大利亚的同事

they saw up to 98 percent reduction in a similar trial.

在类似的试验里得到了 高达 98% 的减少量。

That kind of reduction is simply staggering.

这种锐减简直令人震惊。

And in the graph,

图中，

you see methane emissions in three levels of intake.

你可以看见三种等级的摄入量 对应的甲烷排放量。

So the first line is for cattle with no seaweed,

最上面的线是没有摄入海草的牛。

The second line is for cows

第二条线是

that were supplemented with about 30 to 40 grams of seaweed.

摄入 30 到 40 克海草的牛。

And the last one is for cows

最后一条线是

supplemented with about 60 to 80 grams of seaweed.

摄入 60 到 80 克海草的牛。

As you can see, as you increase the amount of seaweed,

你可以看到，海草的量越大，

you see a reduction in methane emissions.

甲烷排放减少得越多。

We have also seen an improvement in bulking up

我们还发现了可以 在没有健康副作用下

of the beef cattle with no adverse health effects.

增加肉牛的体积。

So it’s a win for the environment;

所以这是对环境的好处，

it's a win for the farmers and consumers.

也是对农民和消费者的好处。

A panel of 112 people got to taste steak

我们做了一个 112 人的 小组试验，品尝

made from steers offered seaweed and control.

由食用海草的肉牛 和控制组制作的牛排。

And they did not detect any difference.

他们没有尝出差别。

We also did a nutritional quality of the meat,

我们还做了一个 牛肉营养质量检测，

and we found no difference between animals that were offered seaweed

没有在食用海草的动物和控制组间

and the control.

发现差别。

So how does it work?

所以是怎么做到的？

Some seaweeds contain ingredients

有些海草包含了一些成分，

that directly inhibit microbes in the cow’s gut from forming methane

可以直接抑制牛的 肠胃微生物形成甲烷，

without interfering with food digestion.

同时不影响食物消化。

The amount of methane produced

生产的甲烷量

is dependent on how much the animal is eating

取决于动物吃多少，

and what's in the diet.

和饲料里有一些什么成分。

And as such,

正因如此，

previous efforts to reduce methane emissions

之前试图减少甲烷排放量的工作

focused on changing their diets

主要关注改变牛的食谱，

or improving forage quality.

或者提高饲料质量。

And we do have potential solutions other than seaweed

我们确实有一些除了海草以外

to reduce methane emissions.

减少甲烷排放的的可行方案。

We looked at additives to feed, such as 3-NOPs,

我们研究了饲养的添加剂， 比如3-NOPS（3-硝基氧丙醇），

reduce emissions by about 30 percent.

可以减少约 30% 的排放。

Even garlic and citrus extract

连大蒜和柑橘提取物

can reduce methane burps by over 20 percent

都可以减少超过 20% 的甲烷嗝，

without affecting animal health and productivity.

并不会影响动物的健康和生产力。

Now you may ask:

你有可能想问：

Why not stop eating beef and drinking milk?

“为什么不停止 吃牛肉、喝牛奶呢？”

Audience member: Yeah!

观众：对！

(Laughter)

（笑声）

EK: That would be a good question.

EK：真是个好问题。

So adopting a plant-based diet with supplements

所以采用基于植物的食谱， 加上添加物，

may help shrink a person's carbon footprint

可能会在像美国这样的高收入国家

in high-income countries like the US.

减少个人的碳足迹。

But, you know, a lot of people are not going to do that.

但是，很多人做不到这些。

And for the rest of the world,

在世界上的其他地区，

these foods are needed to provide key nutrients,

这些食物是用来 提供关键营养物的，

such as vitamin B12 and vitamin A,

比如维生素B12和维生素A，

which are critical for brain function,

对脑功能、

for vision and immunity.

视力和免疫系统十分重要。

These are found almost exclusively in beef and milk.

这些几乎只能从 牛肉和牛奶中获取。

In this graph, you see different countries

在这张图中，你可以 看到用柱状图表示

with their annual meat consumption per capita on the bar graph,

不同国家每年的人均肉类消耗量，

and then you see the dots representing the stunting rate

点状表示

in children below the age of five years old.

五岁以下儿童的发育迟缓率。

And countries that have lower consumption of methane

甲烷消耗量低的国家

are associated with higher incidence of stunting.

与高发育迟缓率有关。

I know this firsthand.

我一开始就知道。

Growing up in Eritrea,

我在厄立特里亚长大，

I loved milk and meat when you could get it,

如果可以得到， 我会很爱牛奶和牛肉，

which wasn't often.

但是我也不常能得到。

Even as a kid, I always wondered

就算是个孩子，我常常思考

how a cow, eating just grass, produces nutritious milk I love to drink.

牛怎么可以只吃草就能生产 我喜欢喝的营养丰富的牛奶。

And that wonder pushed me into a career to understand

这个思考促使我选择了一份

and improve livestock production

研究和改善牲畜生产的工作，

so that people in low-income countries do not suffer with stunting

这样低收入国家的人 不需要受到发育迟缓

and other nutrient-deficiency diseases.

和其他营养不良造成的 疾病带来的折磨。

(Applause)

（掌声）

So what now?

所以现在做些什么呢？

We know seaweed can work.

我们知道海草能行。

But the cultivation of the specific seaweed has been a barrier.

但是培育特定品种的 海草会是一个挑战。

It's not so easy to farm asparagopsis taxiformis.

培育紫杉状海门冬不简单。

But there are a number of efforts going on at the moment

但是现在有许多扩大生产的尝试

to scale up production.

正在进行中。

Blue Ocean Barns is growing seaweed in Hawaii already,

Blue Ocean Barns公司 已经在夏威夷培育海草，

and they estimate that there will be enough production to feed all cattle

他们估计在 2030 年 以前可以有足够的产量

in the US by 2030.

饲养全美的牛。

All we need now is for governments to step up

我们现在需要的是政府站出来

and facilitate the use of these methane-busting feed additives.

促进降低甲烷的 饲料添加物的使用。

Cattle industries in some countries

有些国家的肉牛产业

have already committed to climate neutrality by 2050.

已经承诺在 2050 年 以前达到碳中和。

But if we can get these feed-additive innovations

但是如果我们可以更早地 把这些创新饲料添加物

into cow stomachs earlier,

带进牛的胃，

we can cut methane burps significantly.

我们就可以大量削减甲烷嗝。

Given that methane only lasts in the atmosphere for a decade or so,

甲烷只会在大气层中 逗留大约十年，

we could even slow global warming in the short term.

我们甚至可以借此 在短期内减缓全球变暖。

Yes, we have a methane problem from cows,

对，牛有甲烷问题，

but we may have seaweed and other solutions

但是我们有海草和其他方法

for these methane burps,

解决甲烷嗝，

helping us provide meat and dairy while maintaining a safe climate.

在生产肉类和奶制品的 同时维持气候的安全。

Thank you.

谢谢。

(Applause)

（掌声）