@parados,
parados wrote:"very likely" means it is greater than 90% probability.
The degree of "probability" is not the relative contribution I'm talking about.
For example, before people were ever around, there was a long term average warming trend already taking place. There is a rate to that increase over a selected period of time.
What I would like to see in a scientific report is the change in that rate of that increase, due to human activity.
THAT is the relative contribution by humans which I would like to understand.
If you look at the ice core data it's very clear from the near vertical slope of the increases that some key factor (or combination of factors) happened many thousands of years ago (and has happened just like this many times before) which triggers a cataclysmic spike in global warming which peaks out at the next major factor which results in a return to glaciation (which on average is the nominal temperature range of the planet in recent geologic time).
Then after all that is said and done, and someone can finally say with some degree of accuracy just how much humans have increased the already headlong rush toward the next inevitable peak... just what we should do about it. Because even if we stopped all our carbon activity immediately the previous warming effects would still be there. And they alone are sufficient to repeat the cycle from the ice cores.
I believe that we are much closer to the next oceanic thermohaline cycle breakdown than anyone realizes, and that once that happens
warming is going to be the last thing any one worries about for the next 50,000 years.