综合英语08 Our warming planet.ppt

* Our Warming Planet What has worried many people now is that over the past 250 years humans have been artificially raising the concentration of greenhouse gases in the atmosphere. Our factories, power plants, and cars burn coal and gasoline（汽油）and spit out a seemingly endless stream of carbon dioxide（二氧化碳）. We produce millions of pounds of methane（甲烷） by allowing our trash to decompose in landfills（垃圾堆） and by breeding large herds of methane-belching cattle. Nitrogen-based fertilizers, which we use on nearly all our crops, release unnatural amounts of nitrogen oxide（氧化氮） into the atmosphere. Once these carbon-based greenhouse gases get into the atmosphere, they stay there for decades or longer. According to the Intergovernmental Panel on Climate Change (IPCC) , since the industrial revolution, carbon dioxide levels have increased 31% and methane levels have increased 151%. 1 ⒉ Paleoclimate（古气候） readings taken from fossil records show that these gases, two of the most abundant greenhouse gases, are at their highest levels in the past 420,000 years. Many scientists fear that the increased concentrations of greenhouse gases have prevented additional thermal radiation from leaving the Earth. In essence, these gases are trapping excess heat in the Earth’s atmosphere in much the same way that a windshield traps solar energy that enters a car. Any food leftover, you would have to spit out. 你不得不将任何食物吃剩的部分吐了出来。 Finally ,he decided to spit out what was really on his mind. 最后，他还是决定倾吐他真正想问的话。 Spit out :to flow out suddenly or violently E·g:· Trash: noun something of extremely low quality or value Then we add the picture to the trash zone. You should trash those silly ideas as soon as possible. 你应该尽快丢掉那些糊涂想法。 E·g: 然后，把这个照片添加到 “垃圾” 区中。 2.Verb 丢掉 E·g: adj trashy:of poor quality 无价值的 Synonym: Derivation: Collocation: trash talk 口水战 ，打击对手士气的言论 empty the trash 倒垃圾 field tra