Summary范例

Source 1

Title: Global Catastrophes: A very short Introduction

Author: Bill McGuire

Source: Oxford University Press, 2001

Page: 125

Global warming is about much more than hotter summers, winter floods, and farting cows.

There is absolutely no question that the earth is warming up fast, and few climate scientists would argue with this. The dispute lies in whether or not the warming we are now experiencing simply reflects a natural turnabout in the recent global temperature trend or results from the polluting impact of human activities since the industrial revolution really began to take hold.

Source 2

Title:Global Warming & Its Effects

Author: Nicolas Dalleva

Source: /4933674[accessed March 28, 2007]

A combination of various actions and, in some cases, not enough action causes global

warming in the world today. The leading cause of global warming is the ongoing burning of fossil fuels, which releases carbon dioxide into the atmosphere. Carbon dioxide, along with the other greenhouse gases of methane, nitrous oxide, and chlororfluocarbons, is the cause of the greenhouse effect. This effect is dangerously increasing as the gases are being released in greater quantities.

Source 3

Title:Human Activity Is Altering the Composition of the Atmosphere

Author: John M. Broder

Source: /what-impact-human-activity-has-on-global-warming[accessed December 1, 2011]

In richer and mature societies of the world, such as parts of the northern hemisphere, on the whole, re-growth of vegetation appears to be taking some carbon dioxide out of the atmosphere. Most of the net carbon dioxide emissions from deforestation are currently occurring in tropical regions. Land use changes are responsible for 15 to 20% of current carbon dioxide emissions.

Summary

Human activities are chiefly responsible for climate change. Despite the dispute as to whether global warming is caused by human activities (McGuire, 2001), carbon dioxide have been proved the major factor for climate change. Carbon dioxide will form a thick gas layer as it is constantly building up in the atmosphere. The gas layer is the killer of the ozone layer—the layer which protects the Earth from harmful radiation, thus causing global warming. It is documented that

carbon dioxide is emitted in a number of ways, among which the burning of fossil fuel can obviously release a great amount of carbon dioxide into the atmosphere (Dalleva, 2007). Another way is deforestation such as the conversion of forestland to farms, ranches, or urban use. According to Broder (2011), 15 to 20% of total carbon dioxide emissions is attributed to changes in land use.

References

Broder, J.M. 2011. Human Activity Is Altering the Composition of the Atmosphere /what-impact-human-activity-has-on-global-warming [accessed

December 1, 2011]

Dalleva, N. 2007. Global Warming & Its Effects. Available from:

/4933674[accessed March 28, 2007]

McGuire, B. 2001.Global Catastrophes: A very short Introduction. Oxford: Oxford University Press, 125.