福建省邵武市第七中学高二英语必修六片段教学课件：Unit4Globalwarming.ppt

Unit 4 Global warming;How did come about?;What causes global warming? Human activity or a random but natural phenomenon?What effects does it have on the earth?zxxkw;; A greenhouse is made of glass and is used for growing plants, especially during cold weather.组卷网;How does it work? The air inside is warm because the glass traps the heat from the sun and keeps it from escaping. This makes the greenhouse heat up and so the plants can grow throughout the cold period.;Surely we need greenhouse gases. Without greenhouse effect, the earth would be___________.;As we know,We depend on energy to do many things in our daily lives. For example, energy lights our cities and heats our buildings. Coal, oil and natural gas are called __________________ , which is a kind of energy. But do you know what by________ is produced when we burn fossil fuel? ;Carbon dioxide;Brainstorm: the names of disasters;avalanche(雪崩);;;;10.disappearance/extinction of species;Let’s try to save energy! To save energy is to save our earth! ;Dicussion;