Firstly:
Global Warming / Climate change as a game-mechanic does not fit into CiV as i see it. (Maybe as a scenario). I find it too arbitary and random. You could in theory fill a desert with factories just to raise global warming and ruin everyone elses fertile valleys.
As for actually modelling it into the game in a realistic way, i think that would be too much of a challenge, (as you'd need weather patterns, tidal patterns, etc etc).
I agree an eco-cataclysm would provide a challenge to avoid, but i dont feel it belongs in vanilla CiV.
Secondly:
King Yosef:
I think you should read this:
http://news.bbc.co.uk/1/hi/sci/tech/8618024.stm
Don't believe all the hype stories the media pedal: Climate-Gate! Sea levels will rise 10m by 2020!
Most of the time these are non-scientifically trained journalists reporting an area they know little about, while reporting upper 5% probability results or simply mis-understanding the report/paper they are reading.
The climate gate argument is actually an argument about maths, not about climate change. How do you represent data? Which statistical method is most appropriate? What time period should be looked at?
In one of your posts you have sea-ice data from the last year! wow, a very comprehensive data set covering <0.001% of the earth's lifetime (even post oxidation). In my opinion not long enough to make long term predictions from. One major problem for climate modelling is that there is insufficient data to make long term predictions. Therefore predictions are always presented as percentages chance, and often studies disagree depending on their model.
I am studying for a PhD in aeorosol (an aerosol by the way is gas or liquid particles (dispersed phase) in a gas (dispersion medium)) chemistry, specifically dealing with atmospheric aerosol. I have spent 3 years determing how
5 combinations of 3 components (one inorganic (by which i mean a salt), one organic, and one anthropogenic) affect the size, thermodynamics and kinetics of their aerosol droplets. I use single particle study techniques to investigate one droplet at a time. This data is then passed to modellers to make use of.
During my analysis i have to decide which model i use: AIM (aerosol inorganic model), or ADDEM (aerosol diameter dependant equilibrium model). They have one small but important difference and to be honest 95% of the data from both models is the same. One accounts for curvature effects, the other doesn't. One is used for rough analysis, the other for paper quality final analysis. Why? One takes 10 minutes, the other one takes 1 day.
Furthermore climate change is dependant on many factors both natural and anthropogenic.
Denying that anthropogenic sources effect the climate is incredibly naive. The climate is an extremely complex system.
As an interesting aside:
Most of my research is about how much aerosols cool the atmosphere. Indirect effect, e.g cloud albedo (scattering light from clouds) cools the atmosphere.