What Causes Global Warming?
Scientists think that Global Warming is caused
by the gases produced when humans burn coal, oil, etc. These gases trap
the sun's heat in the atmosphere. Carbon dioxide is made when these fuels
are burned. Percentage of carbon dioxide in the atmosphere has been rising
as result of human industries since the Industrial Revolution.
Heat absorbing gases are known as greenhouse gases. The warming of the atmosphere is called the greenhouse effect. Humans add extra greenhouse gases, which gains a bigger chance in the greenhouse effect. The increase causes global warming.
There are many ways that carbon dioxide is added into the atmosphere. When cutting down deforestation of the world's rain forests, it adds carbon dioxide to the atmosphere. Wood decay, burning wood, cement-making, and fossil-fuels also adds more carbon dioxide. This is all because of the Industrial Revolution.
Carbon dioxide levels still take up less than 1% in the atmosphere, but scientists think the percentage may rise. The carbon dioxide levels in the atmosphere are about 30% higher than in 1860. Carbon dioxide levels may reach to 600 parts per million by the year 2050 and the Earth's temperature may rise from 2 to 6 Fahrenheit by 2100, says the scientists of Intergovernmental Panel on Climate Change (IPCC).
Global warming is also caused by solar radiation in the form of light waves,that pass trough the earth's atmosphere. Most of this radiation is observed by the earth and warms it. But some of the solar energy is radiated out of the earth and into space and its turned into the form of infrared waves. Also some of this out going infrared radiation is trapped by the earths atmosphere and warms the earth again and again, and the atmosphere is being thickened by all of the earth's pollution that the whole world is causing.