While there is still some disagreement about global warming, many scientists believe it is the result of changes in the earth’s atmosphere. The atmosphere creates a blanket that surrounds the earth. Sunlight passes through the greenhouse gases in the atmosphere to reach the earth’s surface and is absorbed. Once this energy is absorbed it goes through various natural processes, such as photosynthesis, and is re-released back into the atmosphere.
Some of the energy escapes the atmosphere, but a considerable amount becomes trapped by the greenhouse gases and causes the earth to warm in temperature. This is known as the greenhouse effect. The greenhouse effect is naturally occurring and vital to our survival. Without it earth would not be warm enough to sustain life. However, many scientists believe the growth of industry and urbanization has had a direct impact on the earth’s atmosphere, resulting in an unhealthy build up greenhouse gases. The general consensus about global warming points in one direction and it seems that evidence of the serious challenge it presents can be directly attributed to human activity.
Carbon dioxide, the gas released during the burning of fossil fuels, such as coal, oil and natural gas heads the list of emissions that are damaging the atmosphere. This is followed by methane, which is released primarily from landfills, mining operations and gas pipelines, chlorofluorocarbons, which have also been found to contribute to ozone depletion, and nitrous oxide, that comes from fertilizers and other chemicals.