Global warming is a change in the earth’s climate that results in higher average temperatures earth wide. While this is a subject is much debated, with some opponents even saying that there is no such thing as global warming, many top leaders and scientists are very concerned and have been investigating this phenomenon for decades.
Scientists have spent many years looking at natural cycles and other events that are known to influence climate. They have looked into evidence from past ice ages and other natural cycles to see if the current situation matches these patterns. However, the amount of warming and the pattern of the warming do not match any of these previously known natural causes. The only explanation that seems to make sense is that it has been caused, or at least augmented, by human activities.
The key human factor in global warming appears to be greenhouse gases emitted by humans. There are number of greenhouse gases that are responsible for the warming and humans emit greenhouse gases in a variety of ways. However, most of them are a direct result of burning fossil fuels and automobiles, factories and in the production electricity.
Most of the warming is being caused by carbon dioxide, also known as CO2. Other major contributors to global warming are methane, nitrous oxide and various refrigeration and industrial gases. Taken together, all of these gases released into the atmosphere act like the glass in a greenhouse. Heat from the sun passes through these gases to the earth, but then is trapped and prevented from leaving. This has the net effect of increasing global temperatures.
The greenhouse gases are naturally occurring and a vital part of our atmosphere. They help to regulate the planet’s temperature and make it suitable for life. For example, Mars has too little greenhouse effect and its surface is frozen, with no sign of life. On the other hand, Venus has too much greenhouse effect. With about 300 times the amount of CO2 as the earth, the runaway greenhouse effect on Venus keeps the surface temperature hot enough to melt lead. The key is to keep the proper balance and to ensure that human activities do not push greenhouse gas levels too far one way or the other. Natural forces have always worked to balance the atmosphere, but current human activities are upsetting the balance and hindering the natural adjustments.
Each of these gases goes from a different source and as different heat-trapping abilities. Methane is being released from landfills and agriculture. It produces more than 20 times the warming of a molecule of C02. Nitrous oxide from fertilizers is 300 times more powerful than C02. Various refrigeration gases, such as chlorofluorocarbons, trap thousands of times the amount of heat of C02. However, it is C02 that gets most of the blame due to the vast quantities being released each year. Even added together, the other gases do not have as much an effect as carbon dioxide.
There are causes beyond the actual release of these greenhouse gases that exacerbate the problem. For example, trees are part of the naturally occurring cycle that converts carbon dioxide into oxygen. Rapid deforestation and burning of trees is a two-edged sword. Not only does the burning release C02, trees that used to absorb and trap the gas are lost.
Methane emissions are also increasing. Methane occurs naturally in the ground. In the arctic, methane is trapped in the frozen permafrost. But as the climate warms, the permafrost begins to melt. This release is even more methane, causing a vicious cycle. Another source of methane is manure. As more animals are being raised as a source of food the source of methane is also increasing.
Unless human patterns and activities are modified, this is a problem that is destined to get worse.