The Cretaceous period ended with a mass extinction event.

白垩纪时期以一次大规模灭绝事件结束。

None of it lines up to say a mass extinction and there is very little evidence to say humans drove the extinction.

没有一个数据指出曾有一次大规模的灭绝，而且很少有证据说是人类导致它们的灭绝。

A mass extinction that happens at less than 10,000 years is very abrupt.

持续时间不到1万年的大灭绝事件是非常突然的。

The climate would be different and a mass extinction would have happened.

气候剧变，这势必会造成生物大灭绝。

Are we knowingly causing a mass extinction? Are we evil? No, of course not.

我们是否故意造成大规模灭绝？我们是邪恶的吗？不，当然不。

About 2.5 billion years ago was a mass extinction of virtually all life on Earth, which barely spared the cyanobacteria.

2.5亿年前是一个地球上所有生命的大灭绝，但几乎没有影响到蓝藻。

So this layer clearly represents that something dramatic had happened on earth that caused a mass extinction in a very short time.

所以这一层黏土清晰地表明地球上曾发生过剧烈变化，并在很短时间内导致了大规模灭绝。

It is also time to take stock, though. Human activities are causing a mass extinction, but the right action now could pull life back from the brink.

虽然现在是时候该算算账了，人类确实让很多物种濒临灭绝，但是我们也已经采取措施将濒临灭绝的物种从消失的边缘救了回来。