Originally Posted by Axiom
the weight of this co2 variable has not been established .
True. The weights (coefficients) of ALL the variables are not yet nailed down. They are all approximates. The really big problem in modelling is that the coefficients effect each other. This creates non-linear responses to CO2 or any other "push" and so called "tipping points."
However, when we give them all the "best" weighting we get a projected 2 degree rise. Give them all the worst weighting and we get 6 degrees. 2=major climate change and a billion dead. 6=total catastrophe with 90-99% of everyone dead.
What we do know is that every time we have made a temperature projection for ten-years hence, the actual outcome has been at the upper end of the calculated range. The current upper end projection is 6 degrees. So, on form alone we should all be worried about the future of humanity.
This is the science. This is the record. This is what we should base our actions upon.