Global Warming Issue | A Presentation in English

Global Warming Issue | A Presentation in English

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LELB Lecturer: Sasan

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/sɔːs/ US /sɔːrs/
noun [C]
1. the place something comes from or starts at, or the cause of something:
a source of heat/energy/light
Oranges are a good source of vitamin C.
Money is often a source of tension and disagreements in young married couples.

2. someone or something that supplies information:
The journalist refused to reveal her sources (= say who had given the information to her).
According to Government sources (= people in the Government) many MPs are worried about this issue.
source /sɔːs/ US /sɔːrs/
verb [T often passive]
to get something from a particular place:
Where possible the produce used in our restaurant is sourced locally.“>Source: www.livescience.com
Global warming is the gradual heating of Earth’s surface, oceans and atmosphere. Scientists have documented the rise in average temperatures worldwide since the late 1800s. Earth’s average temperature has risen by 1.4 degrees Fahrenheit (0.8 degrees Celsius) over the past century, according to the Environmental Protection Agency (EPA). Temperatures are projected to rise another 2 to 11.5 degrees F (1.133 to 6.42 degrees C) over the next 100 years.

Most of the leading scientific organizations in the world acknowledge the existence of global warming as fact, according to a NASA report. Furthermore, 97 percent of climate scientists agree that the rate of global warming trends the planet is now experiencing is not a natural occurrence, but is primarily the result of human activity. That consensus was made clear in a major climate report released Sept. 27, 2013, by the Intergovernmental Panel on Climate Change (IPCC). In that report, climate scientists indicated they are more certain than ever of the link between human activities and global warming.

The greenhouse effect

Global warming begins with the greenhouse effect, which is caused by the interaction between Earth’s atmosphere and incoming radiation from the sun. “The basic physics of the greenhouse effect were figured out more than a hundred years ago by a smart guy using only pencil and paper (Svante Arrhenius in 1896),” Josef Werne, an associate professor in the department of geology and planetary science at the University of Pittsburgh, told Live Science.

Solar radiation passes through the atmosphere to the surface of Earth, where it is absorbed and then radiated upward as heat. Gases in Earth’s atmosphere absorb about 90 percent of this heat and radiate it back to the surface, which is warmed to a life-supporting average of 59 F (15 C). This very helpful process is called the greenhouse effect.

Global Warming Issue | A Presentation in English