Global warming

Global Warming refers to the idea that the Earth's average temperature could significantly increase to the point where it will have noticeable effects on how people live.

There continues to be debate on the following points:

• whether or not the Earth is currently on a general warmining trend
• whether or not this trend, if it is real, will continue
• whether or not this will have significant effects on anyone
• what those effects might be
• whether or not these effects, if real, are being caused by humanity
  • Could be caused by random climatic drift
  • Could be caused by changes in any of countless variables, e.g. the sun's energy output
• whether it is in humanity's best interest to attempt countermeasures (as opposed to "letting nature take its course")
• what sorts of countermeasures should be taken (e.g. should we try to counteract the warming trend itself, or just be prepared to deal with the changing climate and rising sea levels as they happen?)

Evidence pointing to a warming trend seems to be increasing, but many still consider the issue far from resolved.

Difficulty of Resolution

Part of the problem is that the issue has become heavily politicized, largely because direct countermeasures (attempts to counteract the warming trend) tend to be unpopular amongst those who would need to implement them, and those who would need to implement them are generally large businesses with significant amounts of political clout and ability to drive the discussion in directions favorable to them.

Another part of the problem is that determining whether or not the phenomenon is of genuine concern requires the integration of large amounts of data – over long timespans and a large number of different geographical locations – in order to notice subtle real effects without raising false alarms due to temporary or local effects.

Contrary Opinions

Although the majority of scientists agree that global warming is occurring and is caused by humanity, a few disagree; each of these few generally express one of the following positions:

• The Earth is not warming: surface records seem to show a warming trend, but satellite and weather balloon records do not.
• The Earth is warming but the cause is unknown
• The Earth is warming but mostly due to natural processes
• Global warming is occuring but not as much as feared

(Reference: wikipedia:List of scientists opposing global warming consensus)

Another counterargument which seems to come up frequently is the idea that the Earth is self-correcting (generally referred to as Gaia theory) and any warming trend will surely be followed by an eventual cooling trend. Although this may be true in general, there is also strong evidence that Earth has been significantly warmer or colder than at present for quite long stretches of time — apparently even freezing over completely on at least one occasion (Snowball Earth), remaining that way for many millions of years and only unfreezing when the accumulation of geothermally-released carbon dioxide in the atmosphere became sufficient to create a counteracting greenhouse effect.

Reference

• Wikipedia

News Articles

• 2005-09-23 CNN: New era of hurricanes "But don't rush to blame it on global warming, experts warn."
• 2005-09-16 Global warming 'past the point of no return'
• 2005-05-10 The (UK) Guardian: "David Bellamy's inaccurate and selective figures on glacier shrinkage are a boon to climate change deniers"