What is the Greenhouse Effect

The “greenhouse effect” is usually talked about in a negative context, due to its association with global warming. However, the fact of the matter is that life on Earth as we know it could not exist without it. All life on Earth is dependent on the sun for energy. Approximately 30% of the sunlight directed towards the Earth bounces off the outer atmosphere and is sent back into space. The other 70% of the sunlight is reflected upwards by the Earth’s surface, creating what is known as infrared radiation. Greenhouse gases like water vapor, ozone, methane and carbon dioxide then absorb the infrared radiation, thus limiting its escape from the Earth’s atmosphere.

Greenhouse gases only make up about 1% of the Earth’s atmosphere, yet they are extremely important as they serve to regulate global temperature by essentially trapping heat and harnessing it in a sort of warm-air blanket that encompasses the entire planet. This process is what is referred to by scientists as the “greenhouse effect”. Scientists estimate that without the greenhouse effect, temperatures on Earth would be on average about 30 degrees Celsius (54 degrees Fahrenheit) cooler, which would be too cold to sustain our ecosystem as it is today.

While the existence of the greenhouse effect is a vital factor in maintaining life on Earth, it can also be very dangerous if it occurs in excess. Many human activities are known to alter, distort, and accelerate the natural process of warming by producing and emitting more greenhouse gases into the atmosphere than what are required to effectively do the job of creating an ideal overall global temperature. Among the activities that contribute to this problem are the following:
• Burning of natural gas, oil and coal raises carbon dioxide levels in the atmosphere. This also includes the burning of gasoline in motor vehicles.
• Some factories produce industrial gases that do not occur naturally and last for long periods of time. They also contribute to the enhanced greenhouse effect and global warming.
• Certain farming tasks and land-use changes may increase methane and nitrous oxide levels.
• Population growth also has a big impact on the amount of energy that we use as a society. Most of our electricity in the United States comes from non-renewable energy sources such as coal power plants.
• Deforestation is another factor that contributes a great deal to global warming. Carbon dioxide is used by trees, and the trees then give off oxygen. This natural process helps to create an optimal balance of atmospheric gases. Unfortunately, due to the high demand for paper products worldwide, forests are rapidly declining. Trees are often times also cut down to make room for farming.

Basically, more greenhouse gases in our atmosphere means that more infrared radiation is trapped and held, which ultimately raises the surface temperature along with the air in the lower atmosphere. Today, the temperature is already increasing at a rate that is faster than anything previously recorded or determined. Some scientists estimate that by the year 2010 we will see an increase in average global temperature of 1.4 to 5.8 degrees Celsius (2.5-10.5 degrees Fahrenheit).