Climate Policy

[weakwarrior]

For a model to be valid, it does indeed need "to predict the entire global climate past". If it cannot, if it can only predict some eras but not others, then how are we to know that the coming era is one which it can predict? How can we know when we can use it and when we can't?

Ignorant question: since all we want to know is how an increase in CO2 (without any other major global changes - like earthquakes or what not) affects global temperatures why wouldn't modelling what happened since the industrial revolution be sufficient? Has that ever happened before?

Edit: Stupid post. If the baseline is moving on the order of the current deviation it needs to be modelled very carefully.