by Rex Trulove

Created on: January 21, 2008

A big key to the question is the "recent climate changes" part, and there is a very good reason for this. While scientists are barely beginning to scratch the surface as far as explaining the multitude of how's and whys of climate change, one thing they know with some certainty is that it has been going on for billions of years.

Unlike planets like Mercury, the earth has a dynamic ever-changing atmosphere. Equatorial regions are heated more than Polar Regions, and both weather and climate (which are not the same thing) is produced as the heat flows toward those colder areas.

As mentioned before, this has been going on for billions of years. During this time, landmasses have shifted. The way that the landmasses disrupt the flows of oceanic current that also distribute heat, have even more to do with climate than the flow of air in the atmosphere, because salt water is a more efficient conductor of heat than is air. In fact, it is due to the locations of the landmasses today that make it possible for the Earth to have ice caps. Over most of its existence, Earth has had no ice caps at all.

Landmasses continue moving even today, and because of this alone, climate and weather will continue to change, just as they have done for so long. This isn't even considering the many other factors that affect climate.

Consider that at times of very large amounts of moisture in the atmosphere, global temperatures have risen, sometime far faster than they are today. This is because water vapor is the main green house gas, both in effect and in amount. Interestingly, if the water vapor is in the form of cloud cover, much more of the sunlight energy that the earth receives is reflected back into space. This causes global temperatures to drop.

It might be thought of as a fail-safe to prevent the world from becoming either too hot or too cold. The hotter the global climate becomes, the more water is evaporated, and the more cloud cover that is formed. This reflects more energy and causes a cooling, which means that less water is evaporated and less cloud cover is formed. It is somewhat of a perpetual engine on a planetary scale.

Between 10,000 and 11,000 years ago, cloud cover was at a maximum, and the world was locked in an ice age. Cloud cover began to thin, no doubt because of many factors, and the average temperatures have been on the rise ever since. The interesting thing to note is that global temperatures peaked about 2,000 years ago, then the world went through many centuries of

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