"An Inconvenient Truth" with Al Gore is not the most commercially successful documentary film ever, but it's certainly the most politically successful one.

I am, however, left with the feeling that the widespread acceptance and scientific consensus has little to do with rational arguments, and everything to do with politics.

The debate about Global Warming has appeared in the mainstream as being between a gang of kooky deniers (working for Bush or financed by Exxon) on one side, and all the honest scientists of the world on the other side.

The "Truth" about GW was easy to sell to a public that hated Bush across the world. It was easy to sell to green people, who had been starving for environmental progress for decades. It was easy to sell to business people dreaming of profits from green investments. It was easy to sell to everyone dreaming of less reliance on oil, in their private economy as well as in the global power game.

What is the GW theory's merits? Could it be that doomsday scenarios are systematically making headlines, while results pointing to the opposite are ignored?

The documentary's only solid finding was that CO2 level and temperature have been correlated over long time spans as measured from ice cores. But the causality remains speculative. Wild results from extrapolating a temperature graph into the future based on just a few recent observations does not normally qualify as good science.

There are plenty of counter arguments to CO2 as the temperature driver. For example the long time data derived from ice cores shows several cases where temperature started falling before the CO2 level did - but how could temperature possibly  fall at times in history when the CO2 level was close to a peak? Here is an interesting article about this http://wattsupwiththat.com/2009/01/30/co2-temperatures-and-ice-ages/

Suppose the GW theory about CO2 is false, what will be the consequences?

Obviously it will be a waste of investments in green power and bio fuels, which could crowd out more valuable investments, and divert attention from real environmental issues etc. It could also change the tax system away from income tax. But hopefully we'll depend less on oil, and the green investments can help drag the world out of the economic crisis, and reduce other kinds of polution than just CO2?

Maybe the real truth (whatever it is) is not worth pursuing if the "truth" is better for keeping the wheels turning in the direction you want.