by John Cowley

Created on: August 18, 2008   Last Updated: August 21, 2008

Are we being realistic in expecting to overcome global warming by reducing industrial greenhouse gas emissions?

For many the relationship between the emission of industrial greenhouse gases into the atmosphere and global warming is clear cut and not in serious dispute. To emphasize this relationship scientists have produced graphs which purport to show a correlation between increasing pollution levels in the atmosphere and global temperature rises. However, the writer maintains that it is not possible to say with any degree of certainty that this apparent relationship is a causal relationship, one event preceding the other. Some scientists have suggested that the currently observed increases in global temperature could be partly the result of other long-term changes happening to planet earth. The graphical evidence frequently toted in the western media, could simply be the result of two relatively independent phenomena paralleling each other, with little or no direct causal relationship between them. If this is the case then what other factors could possibly be responsible for global warming?

It has long been observed that changes occurring in the oceans have a marked effect on the atmosphere and the weather. An example of this is the warm Atlantic ocean current flowing northwards from South America and consequently helping to keep the coastal parts of the British Isles, which lie in its path, relatively free from the extremes of the northern winter. Off the coast of Florida cool air in contact with a warm ocean expands as it is heated and then is pushed upwards by the surrounding cooler air. The rotation of the earth causes the rising air to spiral and form a cyclone which gathers strength until it reaches landfall bringing high winds and drenching rain. Increased geothermal activity on the ocean floor produces a warming of the sea water in the immediate vicinity and, although the exchange of heat between the upper and lower levels of the ocean is a very slow process, some of this heat eventually reaches the surface. The warmer the surface levels of the ocean are the less dissolved gases, such as carbon dioxide, it can hold in solution and hence they will tend to be released into the atmosphere. Small long term increases in the temperature of the oceans also increases the evaporation rate from its surface which in turn increases the concentrations of water vapor in the atmosphere. Water vapor produces an even larger greenhouse effect than carbon dioxide.

Reducing

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