Global warming refers to an average increase in the Earth's temperature,which in turn causes changes in climate.A warmer Earth may lead to changes in rainfall patters,a rise in sea level,and a wide range of impacts on plants,wildlife,and humans.When scientists talk about the issue of climate change,their concem is about global warming caused by human activities. Step Two Global reading Give the students 10 minutes to read the text as quickly as they can,and ask them to think about these questions in the process of reading. 1.True or False Questions: (1)Carbon dioxide is very poisonous,although it is present in the atmosphere in a small quantity,it does us harm. (2)Carbon dioxide is one of the essential gases to life in theatmosphere. (3)The sea level is rising very slowly from year to year,mainly because of too much rain in these areas. (4)Among the gases in the atmosphere,only the concentration of carbon dioxide may result in preventing heat around the Earth from escaping (5)The concentration of carbon dioxide increased steadily and it will be twice what is now by 2020. (6)Burning coal,oil and natural gas are ways to reduce carbon dioxide in the atmosphere (7)People are the real villains actually. (8)In order to save ourselves,we must have new sources of fuel that do not involve the production of carbon dioxide. 2.Structure PartI (Para.1-3) It introduces an essential gas to life-carbon dioxide and its influence Part 2(para.4-13) It analyzes what carbon dioxide does to the temperature of the Earth and the results Global warming refers to an average increase in the Earth’s temperature, which in turn causes changes in climate. A warmer Earth may lead to changes in rainfall patterns, a rise in sea level, and a wide range of impacts on plants, wildlife, and humans. When scientists talk about the issue of climate change, their concern is about global warming caused by human activities. Step Two Global reading Give the students 10 minutes to read the text as quickly as they can, and ask them to think about these questions in the process of reading. 1. True or False Questions: (1) Carbon dioxide is very poisonous, although it is present in the atmosphere in a small quantity, it does us harm. (2) Carbon dioxide is one of the essential gases to life in the atmosphere. (3) The sea level is rising very slowly from year to year, mainly because of too much rain in these areas. (4) Among the gases in the atmosphere, only the concentration of carbon dioxide may result in preventing heat around the Earth from escaping. (5) The concentration of carbon dioxide increased steadily and it will be twice what is now by 2020. (6) Burning coal, oil and natural gas are ways to reduce carbon dioxide in the atmosphere. (7) People are the real villains actually. (8) In order to save ourselves, we must have new sources of fuel that do not involve the production of carbon dioxide. 2. Structure Part1 (Para.1-3) It introduces an essential gas to life — carbon dioxide and its influence. Part 2 (para.4-13) It analyzes what carbon dioxide does to the temperature of the Earth and the results