2017届高三英语一轮复习同步课件：Unit 4（人教版选修六）

　　It is generally believed that the greenhouse effect resulting from industrial activities destroys the natural environment.Under such circumstances，Ren admitted it would be difficult for the public to accept his viewpoint.He only hoped that both natural and human factors should be taken into consideration when people think about global warming.

　　Answer the following questions. 1．What’s the opinion of some Chinese scholars? 【答案】Global warming has advantages. 2．How did Mr.Ren draw his conclusion? 【答案】This conclusion came after detailed comparison based on historical records of agricultural production between the warmer periods (1750－1790) and the colder periods(1841－1890)． Unit 4　Global warming

　　一些中国科学家认为全球变暖对中国和一些发展中国家很有利。 The other side of the story Some Chinese scholars believe global warming has advantages.They think the warming climate can bring benefits to China and many developing countries. Mr.Ren，a Chinese scientist，began to study global climate change more than a decade ago.He indicated(表明) that the rainfall brought by the summer wind coming off the ocean would improve the ecological environment in some arid(干旱的)or semi­arid areas.In other words，a warmer climate could result in increased agricultural harvest for most parts of China and many developing countries located at the edge of the summer wind.Mr.Zhang，professor of the Institute of Geography，Chinese Academy of Sciences，found that the agricultural production in most parts of China，except for Guangdong Province and coastal areas in the southeast，was higher in warmer periods than in colder ones.

　　Therefore，human activities should not be regarded as the main cause of climate change.“Influences from both human and natural factors should be equally stressed.”Ren said，adding that nobody could be sure at this point whether it was natural influence or the greenhouse effect that was causing the change.

　　This conclusion came after detailed comparison based on historical records of agricultural production between the warmer periods(1750～1790)and the colder periods(1841～1890)．

　　According to Ren，during the 10,000 years before the industrial revolution，cold and warm periods had appeared alternately(交替地)．