Much of the world now lives in an industrial civilization, but this has only become possible because we have the necessary natural resources.

当今世界大部分地区都生活在工业文明之中，但这仅仅是因为我们拥有必要的自然资源才成为可能。

There are three types of natural resource without which industry could not exist. One of these is metal. Without that, we'd have no machines and no transportation.

有三种自然资源是工业存在的基础。第一种是金属。没有它，我们也就不会有机器和交通工具。

Another is fossil fuels, which we need to power those machines.

另一种是化石燃料，我们需要它来为这些机器提供动力。

But there's a third resource that'sessential to connect the different parts of a machine, together with belts and pipes and shock absorbers. And that is rubber. It's now used in over40000 products, from waterproof footwear to surgical gloves.

但是还有第三种资源对于连接机器的不同部件至关重要，它与皮带、管道和减震器一起发挥作用。那就是橡胶。目前它被用于生产4万多种产品，从防水鞋到外科手术手套。

At present, we have two types of rubber in common use. One is natural rubber, which nearly all comes from the para rubber tree.

目前，我们常用的橡胶有两种。一种是天然橡胶，它几乎全部来自帕拉橡胶树。

This was originally native to Brazil, but is now cultivated on plantations in Southeast Asia. Recently, however, concern's been growing that supplies may soon be insufficient for the world's needs.

这种橡胶树原产于巴西，但现在在东南亚的种植园中广泛种植。然而最近，人们越来越担心橡胶供应可能很快就会无法满足全球的需求。

So what exactly is limiting the supply of natural rubber? Well, for one thing, rubber trees don't just spring up overnight. It can take eight to ten years for a tree to start producing rubber, so cultivating them's a slow process.

那么究竟是什么限制了天然橡胶的供应呢？首先，橡胶树不是一夜之间就能长成的。一棵树可能需要八到十年的时间才能开始产胶，因此种植它们是一个漫长的过程。

And this leads to another problem. With most crops, farmers don't have to think very far ahead so they can easily change what crop they produce or how much of a crop they produce if they find the demand for that crop is rising or falling.

这也导致了另一个问题。对于大多数农作物，农民不需要做很长远的规划，因此如果他们发现某种农作物的需求上升或下降，他们很容易就能改变种植的农作物品种或产量。

But if you have to plant eight or ten years ahead, that's much harder.

但是如果你必须提前八到十年进行种植规划，那就要困难得多。

And also the rubber tree is very choosy about where it grows. It needs the right temperature, the right amount of rainfall, and the right altitude not too high and not too low.

此外，橡胶树对生长环境非常挑剔。它需要适宜的温度、合适的降雨量以及不偏不倚的海拔——不能太高也不能太低。

The result is that it can't be grown in the northern or southern parts of the globe, only around the equator.

这就导致了它不能种植在地球的北部或南部地区，只能在赤道附近生长。

Another problem is that the rubber is basically extracted in the same way as it's been done for hundreds of years, and that's by hand by making small cuts in the trunk of the tree and putting a little cup there to catch the latex, as the rubber is called.

另一个问题是，橡胶的提取方法基本上和几百年前一样，也就是手工操作——在树干上割开小口，然后放一个小杯子来收集乳胶（即橡胶的初始状态）。

It's very labor intensive and it's not just the initial production that's limiting supplies with other resources, such as water and glass. When we've finished using them, we can recycle them.

这是一项非常劳动密集型的工作，而且限制供应的不仅仅是初始生产。对于水和玻璃等其他资源，我们在使用完毕后可以进行回收。

But although this is also possible with rubber, it's very difficult, so that also reduces the amount we have available, and in the last few years, there have been new threats to the supply of natural rubber.

但尽管橡胶也是可以回收的，难度却非常大，因此这也减少了我们的可用数量。而且在过去几年里，天然橡胶的供应又面临着新的威胁。

One problem is linked to the fact that nearly all the rubber trees in Southeast Asia are descended from just a small number of seeds brought from Brazil in the19th century.

其中一个问题是，东南亚几乎所有的橡胶树都是19世纪从巴西带来的极少数种子的后代。

This means that there's very little genetic diversity among the trees, which in turn makes them very vulnerable to disease. The most dangerous threat is a fungus which destroyed large numbers of rubber trees in Brazil and which could cause devastation to plantations worldwide.

这意味着这些树种之间的遗传多样性极低，从而使得它们非常容易感染疾病。最危险的威胁是一种真菌，它曾在巴西摧毁了大量的橡胶树，并可能对全球的种植园造成毁灭性的打击。

Another problem is that farmers in Southeast Asia are increasingly turning to the cultivation of palm oil, which is easier and more profitable for them. And finally, in recent years, Southeast Asia, like other parts of the world, has been repeatedly hit by extreme types of weather, and this looks likely to continue in the future.

另一个问题是，东南亚的农民正越来越多地转向种植棕榈油，因为这在他们看来更容易，也更有利可图。最后，近年来，与世界其他地区一样，东南亚多次遭受极端天气的侵袭，而且这种情况在未来似乎还会持续下去。

However, as well as using natural rubber, it's also possible to make rubber synthetically.

然而，除了使用天然橡胶之外，我们也可以人工合成橡胶。

This works very well for some purposes, for example, making engine parts or silicon pots and pans used for cooking.

这在某些用途上效果很好，例如，制造发动机部件或烹饪用的硅胶锅具。

But compared with natural rubber, it's not anything like as strong, and this means it can't replace natural rubber in other products.

但与天然橡胶相比，它的强度远不及天然橡胶，这意味着它无法在其他产品中替代天然橡胶。

For example, while a mixture of natural rubber and synthetic rubber works well in car tires, only natural rubber can stand up to the extreme speeds of aircraft tires during takeoff and landing.

例如，虽然天然橡胶和合成橡胶的混合物在汽车轮胎中表现良好，但只有天然橡胶才能承受飞机轮胎在起飞和降落时的极高速度。

So for some time, scientists have been looking for alternative sources of natural rubber. One that's been known about for some time seems initially to be a rather unlikely source.

因此一段时间以来，科学家们一直在寻找天然橡胶的替代来源。其中一种已被知晓一段时间的替代物，最初看起来似乎是一个极不可能的来源。

It's a wild plant with yellow flowers that we normally regard as a weed when we see it in our gardens, but when it's pulled up and its roots cut open, they're found to contain rubber.

这是一种开黄花的野生植物，当我们在花园里看到它时，通常会把它当成杂草，但拔起它并切开它的根部时，会发现里面含有橡胶。

Now compared to the rubber tree, dandelions produce relatively small amounts of rubber, but unlike rubber trees, they're very adaptable.

与橡胶树相比，蒲公英产出的橡胶量相对较少，但与橡胶树不同的是，它们的适应性极强。

They'll grow in all sorts of places and they don't need rich soil, so at present there are several projects underway investigating the possibility of using dandelions as a source of rubber.

它们可以生长在各种各样的地方，也不需要肥沃的土壤，所以目前有几个正在进行的项目，专门调查使用蒲公英作为橡胶来源的可行性。

Another possibility is a desert shrub grown in Mexico and Texas, which is also.

另一种可能是生长在墨西哥和德克萨斯州的一种沙漠灌木，它同样也是。