That doesn't mean that, as I've said before several times,

这并不意味着如我之前很多次所说
that doesn't mean that everybody has food

并不意味着每个人都有食物了
because the political and distribution problems are significant;

因为政治原因和分配问题差异巨大
but at least the world has enough food.

但至少整个世界有充足的食物
At some point the population demands

总会在某一时候人们的需求增长
will outstrip our ability to produce more food,

会超过我们食物能力的增长
because there's only so much land in the world

因为世界上就这么一点儿
where food can be grown.

适合食物生长的耕地
The productivity has gone up, and up, and up

生产力不断的增长增长再增长
and is starting to plateau in certain parts of the world,

已经开始接近现实世界的最高点
so at what point does this really become a crisis?

那么何时危机才会真正来临呢
Some estimates are that in the next forty years

一些看法认为在未来的四十年