Time to spend some karma. Literature like this makes me happy, because it is further evidence that the alarmists have very little material left. Mercifully we may have hit the high-water mark of this generation of misanthropic environmentalist nonsense and can now enjoy several decades of joking about it. The "Recursive Fury" paper[0] was probably the actual high-water mark, and this looks like pretty much the same t…
Have the models really changed that much in 35 years though? This one has all the highlights, radiation balance, 1D and 3D modeling, climate sensitivity, the main feedbacks (water vapor, lapse rate, clouds, ice- and vegetation albedo); solar and volcanic forcing; and ocean heat uptake. http://www.sciencemag.org/content/213/4511/957 They predict about half a degree C, and that seems to be holding up. More interesting…
Anyway, I don't think we are talking about even close to the same meaning of "complex", but one possible situation that would help convince me is if we had a "control" planet, and an "experimental" planet, with nearly identical climates and biodiversity and so on, and then we raised the CO2 level of the experimental planet, keeping in mind that all kinds of other inputs to the non-linear system should remain the same, like land use, fishing, other industrial activities, etc. If the experimental planet diverged significantly from the control planet, it wouldn't be solid 100% irrefutable proof but it would be far better evidence than anything we have today.