Dinosaurs have been extinct for millions of years.

恐龙已经灭绝几百万年了。

Modern humans arose in Africa about 200,000 years ago.

现代人类大约20万年前出现非洲。

About 10,000 years ago, this crater was created by nature itself.

大约一万年前，这个火山口自然形成。

Moreover, even though humans have been upright for millions of years, our feet and back continue to struggle with bipedal posture and cannot easily withstand repeated strain imposed by oversize limbs.

此外，尽管人类已经直立行走数百万年，但我们的足部和背部仍难以适应两足直立的姿态，无法轻松承受过大的肢体反复施加的压力。

Perhaps willfully, it may be easier to think about such lengthy timescales than about the more immediate future.

不过很有意思的是推测一万年后的事往往比推测明天要发生什么容易得多。

And so some time around 200,000 years ago, our species confronted this crisis.

大约20万年前，我们人类面临着这场危机。

As for whether modern-day humans need to worry about this 405,000-year oscillation?

“那现代人类是否需要担心这种以40.5万年为周期的振荡？”

And mammals took over after the dinosaur mass extinction event 66 million years ago.

哺乳动6600万年前恐龙大灭绝事件后取代了恐龙。

You can't be too careful these days.

还是小心驶得万年船啊。

The eight-centimeter tooth came from the giant megalodon species which is believed to have died out round 2.5 million years ago.

这颗牙齿长达8厘米，是一种巨齿鲨。很多人认为巨齿鲨已大概250万年前灭绝了。

Now, bats have had millions of years of evolution basically to sort of develop these mechanisms to dynamically adjust their emissions.

“现，已经经历了数百万年的进化，基本形成了这种动态调整声音的机制。”

After millions of years, in 2019, the great whites of Cape Town have vanished.

这里生存了数百万年后，2019年，开普敦海域的大白鲨消失不见了。

OK, so we'll start by going back thousands of years.

好的，那就让我们回到千万年之前吧。

We are doing such irreversible damage that long before a million years are up, we will have made this beautiful planet effectively uninhabitable – not just for us but for many other species.

我们所做的破坏是那么地不可逆转，一百万年期限远未来临之前，我们美丽的地球已经不再宜居了——不止是对人类而言，许多其他种也深受其害。

This is the rock that came out of the ocean 25 million years ago, but the tide has left a line of trash all along the beach here, pretty much as far as your eye can see.

这座小岛2500万年前从海里突起出来，但是浪潮给这片海岸带来了成吨的垃圾，目之所及，全是垃圾。

Millions of years of evolution later, you can see the difference.

数百万年的进化之后你可以看出差异 。

Scientists say spent nuclear rods are so hot, they can't even be moved for several decades until they cool down, and that then, they need to be buried at least 3,300 feet underground for a million years.

科学家表示，用过的核棒温度过高，冷却之前的几十年内都无法移动，即使能移动了，它们还需要被埋至少3300英尺的地下100万年。

While inhospitable now, billions of years ago, the landscape of this dusty rock was similar to that of Earth, but somewhere along the way, it became a red wasteland.

虽然现不适宜居住，但数百万年前，这个星球上四处尘埃、石砾遍布的地貌与地球上的地貌相似，但其间，它又变成了一片红色的荒原。

Earth would never be the same - at least not for millions of years.

地球将永远不会和以前一样——至少几百万年内不会。

In 70 million years that's the most ridiculous thing I've ever heard.

七千万年来，这是我听过最荒唐的事。