We can be thankful that carbon dioxide is keeping us comfortably warm, but the concentration of carbon dioxide in the atmosphere is going up steadily and that is where the villainy comes in. In 1958, carbon dioxide made up only 0.0316 percent of the atmosphere. Each year since, the concentration has crept upward and it now stands at 0.0340 percent. It is estimated that by 2020 the concentration will be nearly twice what it is now.
我们该感到欣慰,二氧化碳给我们温暖使我们舒舒服服,但是大气中二氧化碳的浓度正在稳步升高,其恶迹也就由此而生。在1958年,二氧化碳只占大气总量的0.0316%。此后,其浓度逐年悄悄攀升,而现在已达到0.0340%。据估算,到2020年时,二氧化碳的浓度将接近现在的两倍。
This means that in the coming decades, Earth's average temperature will go up slightly. As a result, the polar ice caps will begin to melt.
这就意味着,在未来几十年间,地球的平均温度将要稍许升高。极地冰盖因此将开始融化。
Something like 90 percent of the ice in the world is to be found in the huge Antarctica ice cap, and another 8 percent is in the Greenland ice cap. If these ice caps begin to melt, the sea level will rise, with the result that I have already described.
世界上大约90%的冰都聚积在巨大的南极冰盖中,另有8%在格陵兰冰盖。如果这些冰盖开始融化,海平面将要升高,其结果就是我上面描述的那个样子。
But why is the concentration of carbon dioxide in the atmosphere steadily rising?
可是大气中的二氧化碳浓度为什么正在不断升高呢?
To blame are two factors. First of all, in the last few centuries, first coal, then oil and natural gas, have been burned for energy at a rapidly increasing rate. The carbon contained in these fuels, which has been safely buried underground for many millions of years, is now being burned to carbon dioxide and poured into the atmosphere at a rate of many tons per day.
难辞其咎的有两个因素。首先,在近几个世纪中,先是煤,其后是石油和天然气,以快速增长的态势被用做燃料获取能量。这些燃料中所含的碳,在过去数百万年的岁月里一直安全地埋在地下,而现在正被烧成二氧化碳,并以每天数吨的速率大量排放到大气中。