Unit4_Global_warming课件20(新人教版选修6）.ppt

Unit 4 ; Is the whole world becoming warmer and warmer? Why?; 全球气候变暖是一种“自然现象”。人们焚烧化石矿物以生成能量或砍伐森林并将其焚烧时会产生二氧化碳等多种温室气体。这些温室气体对来自太阳辐射的可见光具有高度的透过性，而对地球反射出来的长波辐射具有高度的吸收性，能强烈吸收地面辐射中的红外线，导致全球气候变暖，也就是常说的“温室效应”。全球变暖会使全球降水量重新分配、冰川和冻土消融、海平面上升等，既危害自然生态系统的平衡，更威胁人类的食物供应和居住环境。;;energy sources;stove;Wind energy is used as power to produce electricity .;where electricity is produced by burning coals.;in which oil is refined and made pure. ;a facility designed to change nuclear energy into electricity.; on the roof of a house on a bright sunny day are used to collect solar energy, making your house warm or heating your water.;The Hydro-electric dams;Guess it!;What source of energy?;Geothermal (地热的) Energy Plant; An energy source is “renewable” when supplies of it never run out and “non-renewable” when one day they will run out.  Which energy sources on your list are renewable and which are non-renewable?;Sources of energy;Pre-reading;;They are made of glass and plants can grow in it when it is cold outside.;How does it work?;Greenhouse gases!;The Earth Is Becoming Warmer – But Does It Matter?;Fast Reading;Sophie Armstrong wrote the magazine article. The name of the magazine is “Earth care”.;3.What do they think about global warming? Do they agree with one another?;4.What are the two graphs about?;5.What is the main topic of the article?;1.The temperature last century didn’t increase much. 2.Everyone believes that global warming is caused by the activities of humans. 3.Janice Foster believes that global warming is caused by burning fossil fuels. 4.Natural gas is a greenhouse gas. 5.Carbon dioxide is a byproduct of burning fossil fuels. 6.People accept Charles Keeling’s data because he took accurate measurements. ;Detailed-Reading ;listening;2. But there are some very different attitudes among scientists towards this issue.”“issue here means the same as the one in___ .A. I bought the new stamp the day of its issue. B. They are talking about o