The Global Warming Chain Reaction
There is some evidence that once global warming begins it produces effects which are self-accelerating - in essence the results of global warming itself can cause even quicker warming of the atmosphere.
One of the largest of these effects is that of water evaporation. As the atmosphere heats up, this warmth produces more evaporation in the oceans, rivers and lakes. The warmer the atmosphere gets the greater the evaporation, and so the greater the amount of water vapour in the air. Now, as we've mentioned in the What is Global Warming Section, water vapour is actually one of the biggest greenhouse gases and causes a great deal of warming in theatmosphere . Therefore, you can see that as the earth heats up it actually contributes to this heating by throwing even more greenhouse gasses in the form of water vapour into the air.
Clouds are another example of this chain reaction effect, although their effects aren't as well understood as that of water vapour. As water evaporates it create more humid conditions in theatmosphere. This can, combined with other effects, lead to more clouds in the atmosphere on a whole. Clouds in the atmosphere act as insulation, capturing heat as it tries to escape into space and emitting it back earthward. Therefore, the more clouds in our skies, the more pronounced the global warming.
A third element of the chain-reaction effect is that of the thousands of square miles of ice which covers our planet, mostly at the north and south poles. Ice is one of the most reflective of the surfaces of earth and so it bounces a large amount of heat and energy straight back out of ouratmosphere upon it's arrival from the sun. As the earth warms up, however, this ice will melt, and cover less and less of the earth. It will naturally be replaced by either land or sea, both of which are much more absorbent of incoming heat. This means that on average a lot more heat from the sun will be stored in the land and seas of our planet than before and will naturally heat the environment more than previously. The more theatmosphere heats, the more ice melts and the more the world heats up.
