新世纪英语专业综合教程unit8课后答案lecturenotes.docVIP

Unit 8 Focus on Global Warming Section One Pre-reading Activities Cultural information 1. Global warming Global warming is the increase in the average temperature of Earth‘s near-surface air and oceans since the mid-20th century and its projected continuation. Most of the observed temperature increase since the middle of the 20th century was caused by increasing concentrations of greenhouse gases, which results from human activity such as fossil fuel burning and deforestation. An increase in global temperature will cause sea levels to rise and will change the amount and pattern of precipitation, probably including expansion of subtropical deserts. Warming is expected to be strongest in the Arctic and would be associated with continuing retreat of glaciers, permafrost and sea ice. Other likely effects include changes in the frequency and intensity of extreme weather events, species extinctions, and changes in agricultural yields. Section Two Global Reading I Text analysis From which perspectives does the text address the issue of global warming? The text addresses the issue from three perspectives — the general public concern, its causes and consequences, and practical actions to tackle the problem. What’s the author’s purpose of writing? To raise people’s consciousness of the potential dangers of global warming, and to suggest some actions to combat it. II Structural analysis 1. Divide the text into parts by completing the table. Paragraphs Main idea 1-2 The author tells the reason why people are now increasingly concerned about global warming. 3-7 The author traces the causes of global warming and discusses the consequences of it. 8-11 The author puts forward some suggestions on what is to be done. 2. Figure out the sub-ideas in the second part. 1) the causes of the rising concentration of greenhouse gases in the atmosphere (Paragraphs 3 and 4) 2) the effect of such concentration on climate change (Paragraphs 5 and 6) 3) the potential threat of global w