⑳methane/'miːθeIn/n.甲烷；沼气　\s\up1(21(21)warm vt.(使)变暖

　　\s\up1(22(22)画线部分是without引导的含蓄虚拟条件句。

　　\s\up1(23(23)Celsius/'selsIəs/adj.(温度)摄氏的

　　\s\up1(24(24)quantities of 大量的　quantity/'kwɒntətI/n.量；数量

　　\s\up1(25(25)tend/tend/vi.趋向；易于；照顾 vt.照顾；护理

　　tend to do 倾向于/往往做

　　\s\up1(26(26)go up 上升；增长；升起

　　[第3段译文]

　　所有的科学家赞同这种观点：人们为了取得能量而燃烧化石燃料如煤、天然气和石油，从而引起了地球温度的升高。这个过程燃烧化石燃料的一些副产品就叫作"温室"气体，其中最重要的就是二氧化碳。贾尼丝·福斯特博士解释说："有一种科学家称之为'温室效应'的自然现象。这种现象就是大气层中少量的气体如二氧化碳、甲烷、水蒸气等吸收太阳的热量，因而使地球变暖。如果没有这种'温室效应'，地球的温度将比现在的温度还要低33摄氏度左右。因此，我们需要那些气体。当我们在大气层中增加了大量额外的二氧化碳时，问题就来了。这意味着更多的热量有被困在大气层中的倾向，从而引起全球气温上升。"

　　We know that the levels of carbon dioxide have increased greatly over the last 100 to 150 years. It was a scientist called Charles Keeling\s\up1(27(27)， who made accurate measurements\s\up1(28(28) of the amount of\s\up1(29(29) carbon dioxide in the atmosphere from 1957 to 1997. He found that between these years the carbon dioxide in the atmosphere went up from around 315 parts to around 370 parts per\s\up1(30(30) million (see Graph 2)．

　　All scientists accept this data\s\up1(31(31). They also agree that it is the burning of more and more fossil fuels that has resulted in\s\up1(32(32) this increase in carbon dioxide. So how high will the temperature increase go? Dr Janice Foster says that over the next 100 years the amount of warming could be as low as 1 to 1.5 degrees Celsius, but it could be as high as 5 degrees.

\s\up1(27(27)Charles Keeling/'kiːlIŋ/查尔斯·基林