Global warming


8.6.6 Define coefficient of volume expansion.


The volume of any matter expands as the temperature increases. This is called volume expansion. One brief example would be the expansion of water. As the temperature of water increases from room-temperature and approaches a boiling temperature, the volume of the water increases.

The coefficient of volume expansion is the degree of expansion divided by the change in temperature, which is called the material's coefficient of volume expansion. This generally varies with temperature (Wikipedia, 2010).


The following is the equation for the coefficient of volume expansion: The γ is the coefficient of volume expansion measurement in K-1. ΔV is increase in volume measured in m3. V0 is the initial volume of water measured in m3. Δθ is increase in temperature measured in K. (Tim Kirk, 2010)

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8.6.7 State that one possible effect of the enhanced greenhouse effect is a rise in mean sea level.


The rise in mean sea level is one possible effect of the enhanced greenhouse effect.

8.6.8 Outline possible reasons for a predicted rise in mean sea-level.


The Enhanced greenhouse effect is one of the major reasons for the predicted rise in mean sea-level. It will affect the mean sea-level in two ways.

  1. The rise in temperature continues to melt glaciers in both the north and south pole, raising the world's mean sea-level (Tim Kirk, 2010).
  2. As the sea water gets warmer and warmer, the sea water will require more volume due to the volume expansion. Thus, this will increase the overall mean sea-level of the globe. (Tim Kirk, 2010)

However, there are two factors that make precise predictions difficult:

  1. The anomalous expansion of water makes the explanation that the mean sea-level rises due to the increase in temperature and volume expansion uncertain. The volume expansion of water occurs as the temperature increases. However, from 0°C to 4°C, the volume of water actually decreases despite the increase in temperature of water. This anomaly makes precise predictions difficult. (Wikipedia, 2010)
  2. There are different effects of ice melting in sea water compared to ice melting on land. The melting of the ice floating in the sea would not have an effect to the mean rise in the sea-level. This is because the volume created by the melted ice replaces the displaced ice volume that has melted away. So the sea-level would stay the same even after the ice melts on the sea. However, if the ice melts from the land, it increases the mean sea-level. This factor makes it difficult to make precise predictions because it is very hard to determine if the ice on the land has melted or the one floating around in the sea has melted. (Wikipedia, 2010)



Resources:
Wikipedia, Initials. (2010). Thermal expansion. Retrieved from http://en.wikipedia.org/wiki/Thermal_expansion
Kirk, Tim. (2007). Global warming (2). Oxford: Oxford.