名校勵志英語演講 第7期:給大學畢業(yè)生的幾個忠告

[00:00.36]If the world continues on a business-as-usual path, 聯(lián)合國政府間氣候變化專門委員會(IPCC)預測， [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”，這會帶來許多更嚴重的變化。 [00:56.03]An example of a tipping point is the thawing of the permafrost. “氣候引爆點”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。

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