气候变化与人体健康【英文】

What is the greenhouse effect?


百度文库


The greenhouse effect is caused by the trapping of heat in the Earth’s atmosphere First the Sun’s high frequency rays of radiation enter into the Earth’s atmosphere in the form of visible light Next the Earth absorbs these rays and radiates them back into the atmosphere as infrared radiation, or heat Since the Earth’s atmosphere includes certain gases which even in small amounts can absorb infrared radiation , gases such as methane, carbon dioxide, fluorocarbons, and nitrous oxide, the infrared radiation is trapped by these gases and can not escape the Earth’s atmosphere Lastly, as the Earth’s atmosphere traps more and more heat the Earth’s atmosphere begins to increase the temperature of the Earth itself
How do we know global warming is happening?
In the top graph at the right we can see the rising levels of carbon dioxide in the atmosphere as measured in parts per million in the atmosphere, measurements having been taken on the island of Mauna Loa, Hawaii
What causes an enhanced greenhouse effect?
The greenhouse effect is caused by human activities which produce the greenhouse gases; carbon dioxide, methane, nitrous oxide and fluorocarbons Carbon dioxide is the main greenhouse gas and is produced by fossil fuel burning power
Global Warming and Human Health
By Carolyn Vasko
How our planet is warming and its direct effect on the human race
What is global warming?
Global warming is a marked and extended change in the Earth’s climate for the warmer Climate change is an extended change in the Earth’s regular pattern of atmospheric conditions and its fluctuations Global warming is caused by an enhanced greenhouse effect caused by human activity

plants, heating systems, factories, and modes of transportation that burn fossil fuels. Deforestation adds to the problem since most forest remove carbon dioxide from the atmosphere in order to produce food through photosynthesis. Methane is another greenhouse gas produced by human use of land, including the livestock we use and such agricultural objects as rice fields, wetlands and marshes Nitrous oxide is produced by the exhaust of cars, human disposal of waste and human use of nitrogen-based fertilizers Fluorocarbons are gases which are emitted when humans use their refrigerators and their air conditioners Humans produce 30 billion tons of carbon dioxide annually, 300-350 million tons of methane, and 7-13 million tons of nitrous oxide, a drastic increase from even fifty years ago