Even after all these years, the academics who work on climate, still have no idea about natural variation. They are still looking to things that are clearly part of natural vartiation and saying “look its now warmer than it has been for a while”. And so, as those of us who understand natural variation pat them on the head try to explain the concept we know they don’t have a clue. All we can do is to hope that the lack of any recent warming will last long enough that they will grow up and begin to understand what they are really dealing with.
Fortunately, we’ve had luck on our side and Father nature has been through enough of a cooling patch to have wiped out any of the expected warming. That hasn’t stopped the nutters, but they’ve been chewing on grizzle trying to convince anyone they are right as long as the pause continues.
To my mind, the only sensible estimate of the effect of doubling CO2 is that of Herman Harde. Because as far as I can see, he’s the only one to have used the latest HITRAN database. And the fact that no one else has published papers, speaks volumes for the kind of fraudsters involved in this area.
BECAUSE WE KNOW THAT IF THE LATEST HITRAN DATABASE HAD SHOWN THAT MORE ACCURATE DATA FOR CO2 LED TO HIGHER WARMING PREDICTIONS, THAT THAT FIGURE WOULD HAVE BEEN STUFFED DOWN OUR THROATS DAY AFTER DAY AFTER DAY!
And so, we know the only reason the IPCC do not use the latest HITRAN database is because it doesn’t help the nutters.
So, yes, the IPCC is still a lunatic asylum – but fortunately, it’s a lunatic asylum with an ever tighter straight jacket as real world data limits their scope for lunacy.
So, what about feedbacks? On the whole, given the evidence of temperature stability during warm periods of the ice-age cycle, I know there are very strong negative feedbacks that come into play during warmer inter-glacial periods and act against further warming.
So, I would take that 0.6C for a doubling of CO2 by Harde, and reducing it perhaps by 33% to around 0.4C. From memory, that means about 0.12C of the 20th century warming would be due to CO2 leaving about 0.4C warming caused by natural variation. (Not all the 0.7 is real – a good proportion is fabricated by fiddling the data and about 0.2C is the current best estimate of that).
On that basis, my best estimate over the next 100 years is that it will get 0.4C warmer. But realistically that has huge errors (+/- 75%? – and it assumes we have enough fossil fuel to double CO2!) However, on top of this we should also get around +/- 0.5-1C of cooling or warming due to natural terrestrial cycles, and if there is a big change in solar cycle , we could see a few degrees additional cooling.
Putting that together, we’ve probably got twice the chance of warming as cooling. The likelihood is that any change will be almost unnoticeable for ordinary people given the much larger variation of local climate and the only way it will be seen is by detailed measurements.
And I would say the historical evidence is very firmly for warmer, higher CO2 periods being generally better for humanity.
Just thinking about this, I realise that my figure is lower than before. The main reason is that I’m no longer trying to “look sensible” and e.g. I’m not trying to take the IPCC figure of CO2 warming of 1.2C, but instead, I’ve decided that if after all this time, the IPCC have not acknowledged Harde’s work, then it shows that their figure is total bullshit. So, only Harde’s figure has any credibility.
The other is that – whilst I’ve always known that feedbacks were low – because everyone else still believes in positive feedbacks, I didn’t give the actual evidence the weighting it deserved.
The evidence clearly points to strong negative feedback coming into play preventing rising temperature in inter-glacials,
Another way of putting that, is that the methodology of trying to model the climate has proven a total disaster. So, I really cannot have any more confidence if a sceptic does it or an alarmist. It’s still a clearly massively flawed technique.
So, like every good engineer, when the theory falls flat and the data wonks are worse than useless, you have to ignore the useless and look for other indicators.
And that’s how I get a central estimate of around 0.4C warming for a doubling of CO2. It’s not that I’ve suddenly found a better way to estimate climate change. It’s just that I’ve now realised there’s no useful information coming out of climate modelling WHOEVER DOES IT!