“Global warming” isn’t so much a debate as it is just an observation. If you look at temperature graphs for the last few hundred years, they all look something like this:
http://www.statcan.ca/english/edu/power/ch6/images/globalwarming.gif
The real debate isn’t over whether or not it’s getting warmer, but rather what is causing it, although there are some wackos out there who apparently don’t believe that it is actually getting warmer. Michael Crichton’s “State of Fear” has popularized the latter belief, and has brought a lot of pop culture into the debate in the same way that “The DaVinci Code” brought fiction into scientific debates about history. (Just what the global warming debate needed - more crap to wade through…)
Anyway, there are alarmists out there who take data like from the above graph and extrapolate it in ways that don’t really make sense, like this graph, which takes a short term bump and extrapolates it into a long term trend:
This makes you think that we’re basically all doomed within our lifetime, which doesn’t really match the long term data. Ignoring stuff like this, though, if you look at the first graph it really does show a global increase in temperature of about half a degree C per century.
The rise in temperature corresponds very well with the amount of pollutants that mankind has been throwing into the environment, which is probably the best argument that global warming is caused by us.
However, if you look at the data for a really long ways back, a completely different pattern emerges:
http://laceylibertarian.us/wp-images/globaltemp.jpg
In this graph, it looks like the “normal” temperature for the earth is around 22 deg C, which is quite a bit warmer than the current average of about 14 deg C. The earth seems to hover around 22 deg C, with occasional “dips” in temperature. This makes it look like we are in the recovery phase from one of these unusually cold “dips”. If this is true, then the fact that the current temperature rise corresponds to mankind’s pollution is just a coincidence.
This is the essence of the debate. Is the current rise in temperature man made, or is it just a natural process? Or, is it both?
It’s worth noting that man and quite a bit of other forms of life on this planet all evolved during the last “cold” period. If the earth does “recover” to a nice and toasty 22 deg C, it could spell doom for us all, since we aren’t adapted to living under those conditions.
I don’t have any good books that I can point you towards. However, just be a bit skeptical about everything that you read, on both sides of the debate. Anything based on computer models is probably a big load of hooey. Computer models are based on our understanding of the earth, and we really only have decent data to work with for recent times. For quite a bit of the earth’s history, the earth’s environment worked in a way that is completely different than what we are used to. For example, the entire area between New York and, say, Florida, had roughly the same temperature, instead of Florida being noticeably warmer like it is now, and scientists really don’t have a good explanation about why this was. Current computer models work fairly well with minor adjustments to the way things are now, but when things change quite a bit from what we are used to, most of the computer models will probably just completely fall apart.