There is evidence that the earth’s climate has warmed slightly in recent history. It is uncertain whether this is part of a natural cycle, is directly attributable to the by-products of modern industry, or some combination of the two. Many individuals theorize that continued artificial production of greenhouse gases will have the direct catastrophic effect of measurable global warming, followed by melting of polar ice and a substantial rise in sea level.
There are several things that bother me with this simplistic analysis.
- The atmosphere is a complex and chaotic system. A single perturbation can have drastic and far-reaching results; El Nino demonstrates this. Global warming would almost certainly have unexpected consequences. If the current climate is in a metastable state, it is possible that global warming could cause it to metastasize to an antediluvian climate. But it is equally possible it could result in a so-called ice age.
- Warmer air holds more water vapor. Such water vapor could accelerate warming by acting as a greenhouse gas, or possibly moderate warming if manifested as cloud cover. Furthermore, evaporation of water would at least partially offset a rise in sea level.
- A rise in ocean temperature will reduce the solubility of carbon dioxide and other greenhouse gases, resulting in further release into the atmosphere. As with the increase in water vapor, this could result in an acceleration of warming.
- Ice cap melting produces freshwater. This increases the solubility of carbon dioxide and other greenhouse gases, at least partially offsetting the reduction in solubility due to temperature increase.
Most superficial popular analysis doesn’t address these points (although since first thinking about this, the movie The Day After Tomorrow portrayed the ice age angle). I’m sure these have been considered as part of scientific analysis, but that makes me wonder if there really is much cause for popular concern. I confess that my own grasp of this issue is only at a popular level.
Some links of interest:
- James Schlesinger on the theology of global warming.
- Khabibullo Abdusamatov maintains that solar activity is largely responsible for global warming, and will result in significant global cooling by the middle of this century.
- A global warming FAQ.
- Some scientists predict a coming cold spell.