英语听力文摘 English Digest 730 全球变暖对灰熊有益处么？（在线收听）

Is Global Warming Good For Grizzlies?

You’ve probably heard that climate change is bad news for many animal species like polar bears. Warmer temperatures mean less sea ice in the Arctic region. And with less ice, there’s less room there is for polar bears to hunt. And so their populations shrink.

But rising temperatures do not affect all animals in equally harmful ways. For some animals, even for some bears, warming may be beneficial. Take, for example, the grizzly.

Like pretty much all animals, grizzly bears thrive when they have more food. A ten year study that followed 112 bears in the Rocky Mountains of Alberta, Canada, has found that warmer temperatures have resulted in grizzlies having easier access to food.

The more food they have, the fatter the bears get. And the more fat lady grizzlies store, the better their chances of having healthy cubs. Cubs born during warmer than normal years were found to grow into larger and healthier adults.

Of course, this in no way negates the fact that climate change is a serious issue requiring immediate and ongoing attention. For every species that may benefit from global warming, many more may suffer and possibly go extinct.

But the study does show that warming does not necessarily spell total gloom and doom for all animal species. Plus, the research may give scientists a clue about how to alter forest harvest designs to increase the grizzly population in the Canadian Rockies. At the moment, there are only around 750 bears in Alberta, making them an endangered species.

全球变暖对灰熊有益处吗？

你可能听说过，气候变化对北极熊等许多动物物种来说都是坏消息。气温升高意味着北极地区的海冰减少。冰少了，北极熊捕猎的空间也就少了。因此，他们的人口减少了。

但气温升高并不会以同样有害的方式影响所有动物。对一些动物，甚至对一些熊来说，变暖可能是有益的。以灰熊为例。

和几乎所有的动物一样，灰熊在食物充足时会茁壮成长。一项对加拿大阿尔伯塔省落基山脉112只熊进行的为期十年的研究发现，气温升高导致灰熊更容易获得食物。

他们吃的食物越多，熊就越胖。而且，大灰熊越胖，它们生下健康幼崽的机会就越大。研究发现，在比正常年份更温暖的年份出生的幼崽会长成更大、更健康的成年人。

当然，这绝不否认气候变化是一个需要立即和持续关注的严重问题。对于每一个可能从全球变暖中受益的物种来说，更多的物种可能会遭受痛苦，甚至可能灭绝。

但这项研究确实表明，气候变暖并不一定意味着所有动物物种都会陷入黑暗和厄运。此外，这项研究可能会给科学家们一个线索，如何改变森林采伐设计，以增加加拿大落基山脉的灰熊数量。目前，阿尔伯塔省只有大约750只熊，这使它们成为濒危物种。