The Consequences of Global Warming
The rise in temperature will have dramatic consequences. The four immediate major affects as a result of the increase in temperature due to greenhouse warming are the rise of sea level, the increase of severity and frequency of storms, the drastic change in rainfall distribution and a change in ecosystems.
The most significant effect will be the rise of sea levels. Sea level will rise as a result of the heating of the oceans which will cause the thermal expansion of water because a liquid at a higher temperature takes up more volume. In addition, the increased temperatures will cause the continued melting of the polar ice caps and Greenland. The melting of these land based ice sheets will add additional water to the ocean whereas sea based or floating ice does not add to sea levels. This is because like in a glass with ice cubes, floating ice cubes melt without causing the level of the water to rise, but a glass with a stack of ice cubes in it will melt, thus increasing the level of water and overflowing the glass. It is very difficult to predict the exact amount of the increase in sea level but it is certain that coastal areas and areas close to current sea level are in jeopardy of being under water. It is projected that hundreds of millions of people could be displaced by rising sea levels.
The melting of the glaciers has an additional implication. Ice is white and is very highly reflective. The scientific term for reflectivity is albedo. A perfect mirror has an albedo of 1.0 and a perfect blackbody that reflects nothing has an albedo of 0. Ice has a very high albedo close to 0.9. This means that the light that strikes the ice is mostly reflected. The light that is reflected is therefore not absorbed by the Earth and therefore does not contribute to the Earth's energy. In addition, reflected light retains its spectral qualities so the reflected light is in the visible spectrum which is transparent to our atmosphere and thereby is sent back out into space unimpeded. When the ice melts, however, it becomes ocean and the ocean conversely absorbs almost all radiation. Thus the ocean has a very low albedo around 0.1. The light then that would have been reflected is now absorbed. This results in a further increase in the temperature and the oceans at the poles heat up much more rapidly than other parts of the globe.
The increase in global temperatures also warms the oceans. The increase of both air and sea temperatures results in more frequent and severe storms. Unfortunately, this is abundantly clear by last year's hurricane season. Last year marked the record number of hurricanes. Although it is impossible to say whether hurricane Katrina is the immediate consequence of global warming, it is clear that global warming is a contributing factor. The increase of temperature will result in a greater number of more powerful storms.
Global warming also has some paradoxical affects. Although some areas will experience more severe rainfall other areas will be plunged into draught. The rainfall will be redistributed around the coastal areas as a consequence of greater temperature differences between the air and land masses. However, the inland areas will undergo greater evaporation from increased temperature thus resulting in drought. These affects will be unpredictable and erratic. Thus we will see a greater increase in drastic weather, so extreme weather can be an indication of global warming.
Inevitably, ecosystems are also affected by the increase in temperature. Temperate zones are shifting thus causing ecosystems to attempt to adapt. Some species will be able to adapt by moving but others will not. This is causing the extinction of many species. It will also affect humans by altering the location in which crops will grow.
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