Carbon dioxide is one of the molecules that make all life possible, but its impact on the environment is just as important. Its normal role in the environment is to reflect the solar radiation back to the Earth, but an elevated level of carbon dioxide in the atmosphere can potentially cause climate change, a phenomenon that "National Geographic" states has serious consequences for the entire globe.
Features
Carbon dioxide is a colorless, odorless nonflammable gas that is made out of one atom of carbon and two atoms of oxygen double bonded together. NASA states that carbon dioxide composes less than 0.1 percent of the Earth's atmosphere, a figure that fluctuates annually with the seasons, yet its effects are profound.
Greenhouse Gas
Most of the solar radiation that reaches Earth is either absorbed by the surface or reflected into space. However, carbon dioxide molecules high up in the atmosphere are known as a greenhouse gas because the vibration of the atoms caused by contact with infrared electromagnetic waves allows them to absorb and re-emit the infrared radiation from the sun back toward the Earth. The amount that remains in the atmosphere has the potential to warm the planet.
Temperature Regulation
Greenhouse gases play an important role in keeping the Earth warm. The University of Michigan reports that the temperature of the atmosphere is about 33 degrees Celsius warmer than it would be without greenhouse gases. Excluding water vapor, carbon dioxide makes up 76 percent of all greenhouse gases.
Carbon Cycle
According to the Environmental Protection Agency, or EPA, billions of tons of carbon dioxide are removed from the atmosphere by natural "sinks" like oceans and plants. Once it cycles through the environment, carbon dioxide is emitted back into the atmosphere through natural sources such as burning, deposit releases and exhalation in animals. When it is balanced and equal, this continuous carbon cycle is usually close enough to zero sum.
Artificial Emissions
The EPA also claims that levels of carbon dioxide in the atmosphere have risen by about 35 percent since the Industrial Revolution. Today the largest culprits of manmade emissions are factories/home heating systems and power plants, which account for a third of the increase. Cars and trucks account for an additional 22 percent, and major transportation makes up the final 11 percent.
