02br
12br
11b10 i'm a unniversity year one students.And my teacher ask us to write an essay about Climate Change.But I have use a lot of material from the testbook. I just have a few my own wods I hope 12b10you can help me to solve this problem. Thank you in advance. 12br
12br
11b10question:12b12br
10 Choose one of the questions below and write an essay using information from the texts on pages 96 to 103 of your source book. 12br
12br
101. Describe the evidence which suggests that human activity has contributed to climate change. Explain how much of this is discernable and outline any areas of uncertainty.12br
12br
12br
12br
11b10my answer:12b12br
11h1

10 Human activity and climate change12h1

10 Nowadays the temperature of the earth is getting higher and higher. And an organization called IPCC did a comprehensive 10research which 10shows that human activities are contributing to climate change and there has been a discernible human influence10on global climate. (Human activity and climate change page 99)12br
12br
10 The human activities such as: the burning of coal, oil, natural gas, the deforestation and various agricultural are changing the 10composition of the atmosphere and causing climate change.( Human activity and climate change page 102) These human 10activities have led to enhanced a number of greenhouse gases, including carbon dioxide, methane, nitrous oxide, chlorofluorocarbons10and ozone10in the lower atmosphere.( Human activity and climate change page 102) The importance of these gases is that they all have10warming effects. Carbon dioxide is produced when coal, oil, and natural gas are burned to produce energy used for transportation, 10manufacturing, heating, cooling, electricity generation and other applications. The use of fossil fuel currently accounts for 80 to 85 10percentage of the carbon dioxide being added to the atmosphere. (Human activity and climate change page 102)12br
12br
10 Furthermore, land use has changed. For example: clearing land for logging, ranching, and agriculture, these activities still lead to10carbon dioxide emission. What’s more, vegetation also contains carbon which is released as carbon dioxide when the vegetation 10decays or burns. However, over the past several hundred years, deforestation and other land use changes in many countries have 10led substantially to atmospheric carbon dioxide enhance. (Human activity and climate change page 102) Although deforestation is 10still occurring in some parts of the northern hemisphere, on the whole, re-growth of vegetation in the north seems to be taking some 10carbon dioxide out of the atmosphere. Land use changes are responsible for 15 to 20 percentage of current carbon dioxide 10emission. (Human activity and climate change page 102)12br
12br
10 And there are still some uncertain areas which we do not know. Ozone in the troposphere, which is in the lower part of the atmosphere, is another important greenhouse gas which results from industrial activities. It is produced naturally and also by human activities. (Human activity and climate change page 103) Based on current data, tropospheric ozone is still an important contributor to the enhanced greenhouse effect. However, In part because ozone is also produced naturally, and because of its relatively short atmospheric lifetime, the magnitude of this contribution is uncertain. (Human activity and climate change page 103)12br
10 10Because of the discernable areas and the uncertain areas, climate change is still a big problem for us to solve. Anyway, what we can do to protect the environment is to use less fossil fuel and to do less deforestation.10 10 12blockquote