聯(lián)合國政府間氣候變化專門委員會(IPCC)預(yù)測,
[00:03.56]the Intergovernmental Panel on Climate Change predicts that,
如果全世界保持現(xiàn)在的經(jīng)濟(jì)模式不變,
[00:06.53]there is a fifty-fifty chance the temperature will exceed 5 degrees by the end of this century.
本世紀(jì)末氣溫5度的可能性是50%。
[00:13.42]This increase may not sound like much, but let me remind you that during the last ice age,
這聽起來好像不多,但是讓我來提醒你,上一次的冰河期,
[00:19.08]the world was only 6 degrees colder.
地球的氣溫也僅僅下降了6度。
[00:22.10]During this time, most of Canada and the United States down to Ohio and Pennsylvania were covered year round by a glacier.
那時,俄亥俄州和賓夕法尼亞州以下的大部分美國和加拿大的土地,都終年被冰川覆蓋。
[00:29.49]A world 5 degrees warmer will be very different. The change will be so rapid that many species,
氣溫上升5度的地球,將是一個非常不同的地球。由于氣候變化來得太快,
[00:36.18]including Humans, will have a hard time adapting.
包括人類在內(nèi)的許多生物,都將很難適應(yīng)。
[00:40.14]I’ve been told for example, that, in a much warmer world, insects were bigger.
比如,有人告訴我,在更溫暖的環(huán)境中,昆蟲的個頭將變大。
[00:44.04]I wonder if this thing buzzing around is a precursor.
我不知道現(xiàn)在身旁嗡嗡叫的這只大蒼蠅,是不是就是前兆。
[00:50.05]We also face the specter of nonlinear “tipping points” that may cause much more severe changes.
我們還面臨另一個威脅,那就是非線性的“氣候引爆點(diǎn)”,這會帶來許多更嚴(yán)重的變化。
[00:56.03]An example of a tipping point is the thawing of the permafrost.
“氣候引爆點(diǎn)”的一個例子就是永久凍土層的融化。
[01:00.14]The permafrost contains immense amounts of frozen organic matter that have been accumulating for millennia.
永久凍土層經(jīng)過千萬年的累積形成,其中包含了巨量的凍僵的有機(jī)物。
[01:06.47]If the soil melts, microbes will spring to life and cause this debris to rot.
如果凍土融化,微生物就將廣泛繁殖,使得凍土層中的有機(jī)物快速腐爛。
[01:12.07]The difference in biological activity below freezing and above freezing is something we are all familiar with.
冷凍后的生物和冷凍前的生物在生物學(xué)特性上的差異,我們都很熟悉。
[01:18.20]Frozen food remains edible for a very long time in the freezer, but once thawed, it spoils quickly.
在冷庫中,冷凍食品在經(jīng)過長時間保存后,依然可以食用。但是,一旦解凍,食品很快就腐爛了。
[01:25.05]How much methane and carbon dioxide might be released from the rotting permafrost?
一個腐爛的永久凍土層,將釋放出多少甲烷和二氧化碳?
[01:29.46]If even a fraction of the carbon is released,
即使只有一部分的二氧化碳被釋放出來,
[01:32.33]it could be greater than all the greenhouse gases we have released since the beginning of the industrial revolution.
可能也比我們從工業(yè)革命開始釋放出來的所有溫室氣體還要多。
[01:39.29]Once started, a runaway effect could occur.
這種事情一旦發(fā)生,局勢就失控了。