Well I guess I should have known better than to ask a serious question, since it quickly devolved into a pissing match between the supporters like you and the deniers showing graphs that somehow are supposed to indicate CO2 has no effect (maybe they gave the wrong link, because I sure don't see that)
Anyway, regarding the models. Yes, I realize that additional data is always plugged into the models. I hope you realize that the way the models interpret the data is CONSTANTLY being modified. It is not as though they have a program called "climate.c" and as they add more input data its output data becomes more accurate. What really happens is that they're adding to the inputs, massaging data they think "doesn't look right" and constantly fiddling with the way the data is interpreted.
Unfortunately many scientists are predisposed to show future warming, because results that conflict with the accepted theory will meet with resistance. This has happened time and again in the history of science. It should not in an ideal world, but scientists are people, and most people don't like to swim against the tide in their life's work, and a large majority is always successful at shutting them out for a long time. Sometimes the minority who are resisted are proven correct. More often of course, they are not, because they're just plain wrong. Maybe try not to be so willfully blind and simply accept what they say because that's what a large majority of climate scientists say, when they know their professional acceptance depends on toeing the line. They're probably right, but groupthink and echo chambers usually cause things to swing too far to the extreme until the proper balance is found.
You were very quick to criticize me because I used the word "warmists" in my post. You'll find in my post history I refer to warmists and deniers equally. I personally think humans are having an effect on the climate, but I'm highly skeptical of the ability of scientists to construct working models considering how they predictions the models make are constantly running into problems (like Antarctica) and the way the input data is often massaged - seemingly always in the direction of helping the cause of warming - is very troubling to me.
The worst offense though that causes me to be seriously skeptical of those advocating for the cause is the differing treatment of events occurring in the present. For example, in the eastern 2/3 of the US the temperature has been below average for I believe 14 months running. The state in which I live had its coldest July on record (going back nearly 150 years) If a denier makes the stupid claim that it is evidence that global warming is wrong, they'll be told that the long term trend is what matters, not what happens over very short time scales such as a year. And rightly so.
However, warmists seem to have no trouble pointing out the record heat in most of the rest of the world over the past year, and all sorts of "extreme weather events" from California's record drought, to record flooding in parts of Europe, to major storms like Katrina and Sandy they say are "becoming more common", to the absence of major storms - yes, I did see a climate scientist from NOAA on TV claiming that the recent absence of hurricanes in the Caribbean over the past half decade or so is the sort of "disruption of normal climatic patterns" you'd expect from global warming!
Basically the warmists want to count everything as a checkbox in their column, but there is no way for the deniers to compete. I feel confident that if we experienced a decade long drop of 1 to 2 degrees, the warmists would claim it is normal variation but the upward trend is still intact, look for reasons in solar activity, volcanos, climactic feedback cycles or whatever else to excuse it and keep pushing their cause.
That's why I remain skeptical. I think we should try to reduce CO2 output through renewable energy, replacement of coal/oil with natural gas, conservation, etc., but the alarmist view that we're doomed if we don't make massive cutbacks in the next decade or two are just the product of the echo chamber most of those researchers are locked into.