Environmental Protection(环境保护演讲PPT)

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Greenhouse effect
Population growth is another factor in global warming, because as more people use fossil fuels for heat, transportation and manufacturing the level of greenhouse gases continues to increase. As more farming occurs to feed millions of new people, more greenhouse gases enter the atmosphere
Global warming
What is the global warming?
Global warming is the continuing rise in the average temperature of Earth's atmosphere and oceans.
Global warming
Greenhouse effect
How Do Humans Contribute to the Greenhouse Effect?
While the greenhouse effect is an essential environmental prerequisite for life on Earth, there really can be too much of a good thing. The problems begin when human activities distort and accelerate the natural process by creating more greenhouse gases in the atmosphere than are necessary to warm the planet to an ideal temperature.
Environmental Protection
Team from landscape architecture class X Team Members：
Our topic
What do you know about greenhouse effect? Global warming? Rising sea levels? The impact on the earth?
What is the impact of global warming?
Such an unusually rapid rate of change would affect fundamental Earth systems upon which our very lives depend (R)C including ocean circulation and the hydrological, carbon and nutrient cycles. It would disrupt the natural and managed ecosystems that provide us with water, food and fiber. It would add to existing environmental stresses such as desertification, declining water quality, stratospheric ozone depletion, urban air pollution and deforestation. ______”How will global warming affect our world” (the booklet of PICC)
Greenhouse effect
Many factories produce long-lasting industrial gases that do not occur naturally, yet contribute significantly to the enhanced greenhouse effect and "global warming" that is currently under way.
Greenhouse effect
Life on the earth depends on energy from the sun. About 30 percent of the sunlight that beams toward Earth is deflected by the outer atmosphere and scattered back into space. The rest reaches the planet's surface and is reflected upward again as a type of slowmoving energy called infrared radiation.
The heat caused by infrared radiation is absorbed by "greenhouse gases" such as water vapor, carbon dioxide, ozone and methane, which slows its escape from the atmosphere. Although greenhouse gases make up only about 1 percent of the Earth's atmosphere, they regulate our climate by trapping heat and holding it in a kind of warm-air blanket that surrounds the planet.
Deforestation also contributes to global warming. Trees use carbon dioxide and give off oxygen in its place, which helps to create the optimal balance of gases in the atmosphere. As more forests are logged for timber or cut down to make way for farming, however, there are fewer trees to perform this critical function.
Greenhouse effect
The greenhouse effect is a naturally occurring process that aids in heating the Earth's surface and atmosphere. It results from the fact that certain atmospheric gases, such as carbon dioxide, water vapor, and methane, are able to change the energy balance of the planet by absorbing longwave radiation emitted from the Earth's surface. Without the greenhouse effect life on this planet would probably not exist as the average temperature of the Earth would be a chilly -18° Celsius, rather than the present 15° Celsius
Ultimately, more greenhouse gases means more infrared radiation trapped and held, which gradually increases the temperature of the Earth's surface and the air in the lower atmosphere.
Outline
• • • Greenhouse effect Global warming Rising sea lLeabharlann Baiduvels
Greenhouse effect
What is the greenhouse effect ?
On a sunny winter day, you park your car in the sun, lock it, and go cruise the local shopping mall for a couple of hours. When you come back later and get into your car, what do you notice? Is the interior of the car hot or cold? How does the temperature inside of your car compare to the temperature outside? If you have ever been inside of a greenhouse, especially when the sun is out, what have you observed? It is definitely warm, and usually the air is moist. A greenhouse is commonly warmer than the outside air because a greenhouse has the ability to trap heat inside of it. This phenomenon is called the greenhouse effect.
2. Increased probability and intensity of droughts and heat waves
Global warming
3.Polar ice caps melting The ice caps melting is a four-pronged danger. (the leftside picture )
Reference: http://www.environmentalgraffiti.com http://www.ipcc.ch/
Global warming
1.Spread of disease As northern countries warm, disease carrying insects migrate north, bringing plague and disease with them. Indeed some scientists believe that in some countries, thanks to global warming, malaria has not been fully eradicated.
Greenhouse effect
Burning natural gas, coal and oil including gasoline for automobile engines-raises the level of carbon dioxide in the atmosphere.
Some farming practices and landuse changes increase the levels of methane and nitrous oxide.