Yogi Berra, a US baseball player and philosopher, said, "If we don't know where we're going, we might not get there."
美国棒球运动员兼哲学家Yogi Berra说过：“如果不知道哪是我们的目的地，我们就无法到达。”
Accumulating scientific knowledge is giving us greater insights, greater clarity,
不断累积的科学知识带给我们更深刻的见解，更大的清晰度，
into what our future might look like in a changing climate and what that could mean for our health.
让我意识到我们的未来在气候的变化下会是什么样子以及对我们的健康意味着什么。
I'm here to talk about a related aspect,
我今天在这里要讲解的是与之相关的一个方面，
on how our emissions of greenhouse gases from burning of fossil fuels is reducing the nutritional quality of our food.
就是我们通过燃烧化石燃料产生的温室气体，正在降低我们食物的营养质量。
We'll start with the food pyramid. You all know the food pyramid.
让我们从食物金字塔开始说起。我们都知道食物金字塔。
We all need to eat a balanced diet. We need to get proteins, we need to get micronutrients, we need to get vitamins.
我们都需要均衡饮食。我们需要摄入蛋白质，我们需要摄入微量元素，我们需要摄入维他命。
And so, this is a way for us to think about how to make sure we get what we need every day so we can grow and thrive.
所以，这是我们思考如何保证我们每天所需的方法，这样我们可以茁壮成长。
But we eat not just because we need to, we also eat for enjoyment.
但是我们不仅因为身体需要而吃，我们也为了享受而吃。
Bread, pasta, pizza -- there's a whole range of foods that are culturally important.
面包，意大利面，披萨等等，有很大一部分的食物在文化层面上非常重要。
We enjoy eating these. And so they're important for our diet, but they're also important for our cultures.
我们非常喜欢吃这些。所以它们不只对我们的饮食很重要，对我们的文化也非常重要。
Carbon dioxide has been increasing since the start of the Industrial Revolution,
自从工业革命的开始，二氧化碳排放量就在逐渐增加，
increasing from about 280 parts per million to over 410 today, and it continues to increase.
从开始的280ppm(到现在的410ppm，而且还在继续增长。
The carbon that plants need to grow comes from this carbon dioxide.
植物生长所需的碳来自于这些二氧化碳。
They bring it into the plant, they break it apart into the carbon itself, and they use that to grow.
它们吸收二氧化碳，分解成碳本身，然后利用其来生长。
They also need nutrients from the soil. And so yes, carbon dioxide is plant food.
它们也需要从土壤里摄入营养。所以，是的，二氧化碳是植物的食物。
And this should be good news, of rising carbon dioxide concentrations, for food security around the world,
提升二氧化碳的浓度，对于全世界的食品安全都应该是好消息，
making sure that people get enough to eat every day.
可以保证人们每天有足够的食物。
About 820 million people in the world don't get enough to eat every day.
世界上有8亿2千万的人没有足够的食物。
So there's a fair amount written about how higher CO2 is going to help with our food security problem.
所以对于还要多高的二氧化碳可以帮助解决我们的食品安全问题，人们进行过很多讨论。
We need to accelerate our progress in agricultural productivity to feed the nine to 10 billion people who will be alive in 2050
我们需要加快农业生产进度，来养活到2050年，地球上将出现的90到100亿人口，
and to achieve the Sustainable Development Goals, particularly the Goal Number 2,
以实现可持续发展目标，特别是目标2，
that is on reducing food insecurity, increasing nutrition, increasing access to the foods that we need for everyone.
让食品更加安全，增加营养，让每个人得到所需的食物。
We know that climate change is affecting agricultural productivity.
我们知道气候变化正在改变着农业生产力。
The earth has warmed about one degree centigrade since preindustrial times.
自工业化时代以来，地球的温度已经升高了1摄氏度。
That is changing local temperature and precipitation patterns,
这正改变着局部的温度和降水模式，
and that has consequences for the agricultural productivity in many parts of the world.
这对世界很多地方的农业生产力有着重大的影响。
And it's not just local changes in temperature and precipitation, it's the extremes.
而且这并不只是对局部气温和降水的影响，而是非常极端的影响。
Extremes in terms of heat waves, floods and droughts are significantly affecting productivity.
严重的热浪，洪水和干旱正在严重影响着生产力。
And that carbon dioxide, besides making plants grow, has other consequences as well,
而二氧化碳，除了帮助植物生长以外，也有其它副作用，
that plants, when they have higher carbon dioxide, increase the synthesis of carbohydrates, sugars and starches,
当植物摄入过高的二氧化碳，提高了碳水化合物，糖和淀粉的合成，而
and they decrease the concentrations of protein and critical nutrients.
降低了蛋白质和关键营养物质的浓度。
And this is very important for how we think about food security going forward.
而这对我们思考未来的食品安全非常重要。
A couple of nights ago in the table talks on climate change, someone said that they're a five-sevenths optimist:
在几天前的一个关于气候变化的谈话中，有人提到他们是七分之五乐观主义者：
that they're an optimist five days of the week, and this is a topic for the other two days.
意思是每周有五天他们是乐观的，而另外两天不是。
When we think about micronutrients, almost all of them are affected by higher CO2 concentrations.
当我们想到微量元素时，基本上所有微量元素都受到更高浓度的二氧化碳影响。
Two in particular are iron and zinc.
特别是铁和锌。
When you don't have enough iron, you can develop iron deficiency anemia.
当你没有摄入足够的铁时，会触发缺铁性贫血。
It's associated with fatigue, shortness of breath and some fairly serious consequences as well.
这会导致疲劳，呼吸急促和其它一些非常严重的症状。
When you don't have enough zinc, you can have a loss of appetite.
而当你摄入锌不足的时候，可能会导致没有胃口。
It is a significant problem around the world.
这是全球范围内的严重问题。
There's about one billion people who are zinc deficient.
有大约10亿人缺锌。
It's very important for maternal and child health. It affects development.
这对于母亲和孩子的健康尤为重要。它影响着孩子的生长。
The B vitamins are critical for a whole range of reasons. They help convert our food into energy.
维他命B在很多方面都非常关键。B族维他命帮助把我们的食物转化为能量。
They're important for the functions of many of the physiologic activities in our bodies.
对于我们身体中很多的生理活动机能都非常重要。
And when you have higher carbon in a plant, you have less nitrogen, and you have less B vitamins.
而且当在植物中有过高的碳，氮含量就会减少，维他命B也会减少。
And it's not just us. Cattle are already being affected because the quality of their forage is declining.
而这不只会影响我们。由于草饲料质量的下降，牛也已经受到了影响。
In fact, this affects every consumer of plants. And give a thought to, for example, our pet cats and dogs.
实际上，它影响着所有植物的消耗者。想一下，比如我们的宠物猫狗。
If you look on the label of most of the pet and dog food, there's a significant amount of grain in those foods.
如果你仔细看狗粮，猫粮产品的标签，这些食物里包含大量的谷物。
So this affects everyone.
它影响着每个生物。
How do we know that this is a problem?
我们是如何知道这是个问题的呢？
We know from field studies and we know from experimental studies in laboratories.
我们从一些实地考察，从实验室的实验研究得知这些。
In the field studies -- and I'll focus primarily on wheat and on rice
在实地考察中--我会主要关注小麦和水稻，
there's fields, for example, of rice that are divided into different plots.
例如，水稻田会被分成不同的地块。

And the plots are all the same: the soil's the same, the precipitation's the same -- everything's the same.
这些地块完全一样：一样的土壤，一样的灌溉方式--所有条件都一样。
Except carbon dioxide is blown over some of the plots.
除了吹到田里的二氧化碳。
And so you can compare what it looks like under today's conditions and under carbon dioxide conditions later in the century.
所以你可以比较在现在的二氧化碳情况和本世纪后期二氧化碳的情况下对作物的影响。
I was part of one of the few studies that have done this.
我参与了这些实地考察中的一部分。
We looked at 18 rice lines in China and in Japan and grew them under conditions that you would expect later in the century.
我们查看了在中国和日本的18条水稻生产线，它们是在我们预期中的本世纪后期的二氧化碳情况下生长。
And when you look at the results, the white bar is today's conditions, the red bar is conditions later in the century.
现在让我们来看结果，白柱是现在的情况，红柱是本世纪后期的情况。
So protein declines about 10 percent, iron about eight percent, zinc about five percent.
可见蛋白质含量降低了10%，铁8%，锌大约5%。
These don't sound like really big changes, but when you start thinking about the poor in every country who primarily eat starch,
听起来这些不是什么大变化，但是当你想到每个国家主要以吃淀粉为生的穷人时，
that this will put people who are on the edge over the edge into frank deficiencies, creating all kinds of health problems.
这会把那些生存在贫穷边缘的人推向营养严重不足的一边，导致各种安全健康问题。
The situation is more significant for the B vitamins.
情况对于维他命B族更加严重。
When you look at vitamin B1 and vitamin B2, there's about a 17 percent decline.
我们看维他命B1和B2，都大约降低了17%。
Pantothenic acid, vitamin B5, is about a 13 percent decline. Folate is about a 30 percent decline.
泛酸，维他命B5下降了大约13%。叶酸降低了30%。
And these are averages over the various experiments that were done. Folate is critical for child development.
而这些是我们所做的各种实验的平均值。叶酸对于胚胎的成长非常关键。
Pregnant women who don't get enough folate are at much higher risk of having babies with birth defects.
孕妇如果不能摄入足够叶酸会有更高风险造成婴儿缺陷。
So these are very serious potential consequences for our health as CO2 continues to rise.
所以这些都是二氧化碳持续增长会对我们的健康带来的潜在严重后果。
In another example, this is modeling work that was done by Chris Weyant and his colleagues,
接下来的例子，是由Chris Weyant和他的同事做的建模工作，
taking a look at this chain from higher CO2 to lower iron and zinc
来看这个从高二氧化碳到低锌低铁的链条，
and they only looked at iron and zinc -- to various health outcomes.
他们研究了铁和锌与各种健康状况的关系。
They looked at malaria, diarrheal disease, pneumonia, iron deficiency anemia, and looked at what the consequences could be in 2050.
他们研究了疟疾，腹泻，肺炎，缺铁性贫血，研究了2050年结果会是什么样。
And the darker the color in this, the larger the consequences.
在图里颜色越深，代表造成的后果越大。
So you can see the major impacts in Asia and in Africa,
你可以看见在亚洲和非洲的主要影响，
but also note that in countries such as the United States and countries in Europe, the populations also could be affected.
但是要注意，在美国和欧洲各国，人们也受到了影响。
They estimated about 125 million people could be affected.
他们估计大约1亿2千500万人会受影响。
They also modeled what would be the most effective interventions, and their conclusion was reducing our greenhouse gases:
他们同样模拟了哪种是最有效的干预措施，而结论就是要减少温室气体：
getting our greenhouse gas emissions down by mid-century so we don't have to worry so much about these consequences later in the century.
在本世纪中期减少温室气体的释放，我们就不需要担心那些对本世纪后期产生的影响。
These experiments, these modeling studies did not take climate change itself into account.
这些实验，模型的研究没有把气候变化考虑在内。
They just focused on the carbon dioxide component.
他们只是专注于二氧化碳部分。
So when you put the two together, it's expected the impact is much larger than what I've told you.
所以当你把这两部分放在一起，可以预期那些影响将比我之前所说的还要严重。
I'd love to be able to tell you right now how much the food you had for breakfast, the food you're going to have for lunch,
此时我非常想告诉你们，我们早餐和午餐吃的食物，
has shifted from what your grandparents ate in terms of its nutritional quality.
从营养质量的角度跟我们祖父母所吃的有什么不同。
But I can't. We don't have the research on that.
但是我不能。我们没有那方面的研究。
I'd love to tell you how much current food insecurity is affected by these changes.
我非常想告诉你们有多少食品的安全性被这些变化影响。
But I can't. We don't have the research on that, either.
但是我不能。我们也没有这方面的研究。
There's a lot that needs to be known in this area, including what the possible solutions could be.
在这个领域还有很多需要探索的东西，包括可能的解决方案是什么。
We don't know exactly what those solutions are, but we've got a range of options.
我们不知道确切的解决方案，但是我们有一系列选择。
We've got advancements in technologies. We've got plant breeding.
我们有技术的进步。我们有植物育种。
We've got biofortification. Soils could make a difference.
我们有生物强化。土壤可以带来变化。
And, of course, it will be very helpful to know how these changes could affect our future health
而且当然，它有助于我们知道这些变化如何影响人们未来的健康，
and the health of our children and the health of our grandchildren.
以及我们孩子、子子孙孙的健康。
And these investments take time. It will take time to sort all of these issues out.
这些投入都需要时间。需要时间来把问题整理清楚。
There is no national entity or business group that is funding this research.
没有国家实体或者商业机构在资助这些研究。
We need these investments critically so that we do know where we're going.
我们非常需要这些投资，这样就可以知道我们的方向。
In the meantime, what we can do is ensure that all people have access to a complete diet,
同时，我们可以做的事情是确保所有人能够得到完整的饮食结构，
not just those in the wealthy parts of the world but everywhere in the world.
不只是那些富裕的地方，而是世界上所有地方。
We also individually and collectively need to reduce our greenhouse gas emissions
我们从个人和集体的角度都要减少温室气体的排放，
to reduce the challenges that will come later in the century.
这样才能减少本世纪后期会出现的那些挑战。
It's been said that if you think education is expensive, try ignorance. Let's not.
有人说过，如果你认为教育很昂贵，那么试一试无知的代价。但是我们不能这样。
Let's invest in ourselves, in our children and in our planet. Thank you.
让我们为自己投资，为我们的孩子和地球投资吧。谢谢大家。