Greenhouse effect

Greenhouse effect

Human activities contribute to global warming by increasing the greenhouse effect. The greenhouse effect occurs when certain gases known as greenhouse gases collect in the Earth's atmosphere. These naturally occurring gases in the atmosphere include carbon dioxide, methane, nitrogen oxides, and fluorinated gases, also known as chlorofluorocarbons (CFCs).

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Greenhouse gases illuminate the surface of the earth with sunlight, but confine the heat that is reflected back to the atmosphere. In this way, it acts like an insulated glass wall in a greenhouse. The greenhouse effect keeps the Earth's climate comfortable. Without it, the surface temperature will be about 33 degrees Celsius (60 degrees Fahrenheit) low and many life forms will freeze.

Since the Industrial revolution in the late 1700s and early 1800s, people have released large amounts of greenhouse gases into the atmosphere.This amount has soared over the past century.Greenhouse gas emissions increased by 70% between 1970 and 2004. Meanwhile, carbon dioxide , the most important greenhouse gas, has increased by about 80% .The amount of carbon dioxide in the atmosphere today is far beyond the natural range seen in the last 650,000 years.

Most of the carbon dioxide that people release into the Atmosphere comes from burning fossil fuels such as oil, coal, and natural gas. Cars, trucks, trains and airplanes all burn fossil fuels. Many power plants also burn fossil fuels.