Re: Greenhouse gas
(1) It is quite new. Older, simpler models did not exhibit this warm bias. Not even sure all new ones do: some certainly do however.
Yes, they did. Everything from Hansen's infamous testimonial model onwards. His, and now Schmidt's GISS models have been notoriously hot.
If your model runs hot then you know that it does as soon as you have run it from 1850 or whenever you choose to start. Is not the case that climate person would ever say that. well, if model predicts oceans boiled in 1970 they must have boiled in 1970 and we are all now living in matrix or anything less silly than that.
You would hope so, but that's not what has been happening. Climate models are notoriously crude, but that's just the nature of the beast. Break an entire planetary ecosystem into a small number of cells, add 4-5 parameters per cell, run the model. Claim anything from 2-11C, claim funding, call anyone who disagrees with simulated reality a denier. Both Hansen and Schmidt have been doing this for decades.
But such is politics. Reanalysis isn't new, and CMIP6 is just the latest comparison to go along with the latest IPCC report. Which often gets called 'science', even though it's a highly politicised literature review. Especially when vested interests focus on the SPM, which is an entirely political document.
The other challenge is of course the reality you choose, and the bits of reality you choose to ignore. So for example in claiming July's been the hottest in human history, and therefore build windmills-
Which shows a couple of interesting data points. Like all the ones in grey where there's no data. But in sim-science, absence of data isn't a problem as it can simply be invented. Again GISS is notorious for kridging and assuming constant temperatures over thousands of square kilometers covering varying geography. But for July's doom mongering, NOAA also seems not to have noticed record cold temperatures affecting crops across Brazil.
But see also-
Ancient tree stumps found under Breiðamerkurjökull glacier in Southeast Iceland are confirmed to be roughly 3,000 years old. RÚV reports.
A specialist believes the remarkably well-preserved stumps were part of a massive forest that disappeared after a long period of a warm climate.
And inconvenient finds like this aren't unique to Iceland. But get denied by sim-scientists because the 21st Century is the hottest ever because CO2. Trees and other vegetation uncovered by glacial retreat were obviously growing in microclimates under the ice..
(3) These are simulations of physics system. There is no knob in them which says 'adjust climate sensitivity' because there is no knob in the physics system they simulate to do that
Yes there are. The Science article basically says that, ie the way the clouds have been simulated. If you looked into how climate models work, you'll find all have degrees of parameterisation and assumptions about how ocean or atmosphere is meant to work in that model. How the assumptions are programmed produces confirmation biases, or just the parameterisations produce wildly diverging results from reality.
In theory, this should be a good thing. So if simulation is very different to reality, reality is probably right, and something is wrong with the model. Or just call anyone who points that out a denier, and demand even more money to produce wrong results faster.
And once you have started one of these big runs that's it: you can't just change the model even if you discover in 2019 what the problem is because you obviously must submit all your runs from the same model and not cheat.
Or you do cheat, and adjust historic temperature data. Cool that, and voila, an exagerated warming trend. This sadly happens a lot. See 'disputed' 1920's American temperature results. Plenty of historical documentation around the Dust Bowl, and Great Depression. But if temperatures were higher then than now, that doesn't fit with CO2 dogma. See also continued attempts to erase the MWP, LIA, RWP and various other inconvenient bits of history..
So you are stuck now: might say 'let's just put back CMIP6 deadline' but turns out that humans have not much time left to deal with problem
Well, you're right about deadlines. Flights and hotels for 20,000 people heading for Glasgow with the expectation of 'wealthy' nations giving the UN $100bn a year just can't wait. I mean the UN managed the Oil for Food programme so well that a chap by the name of Maurice Strong got given personal cheques for his valuable work! And then went on to trying that scam again with the UN EP. $100bn a year, and the UN's.. lax accounting standards is great business!
Of course if climate sensitivity is low, and assumptions wrt CO2 are correct, like ECS per doubling CO2.. then we have all the time in the world. There isn't enough carbon to double CO2 levels again, and so at around 1.2C/doubling, it's a non-problem.
But still people either uninformed or malignant say 'oh those silly climate scientists they are making things up'.
Indeed. Wheel out a Greta to poute and go "How Dare You!". Greta Mk1 was David Suzuki's daughter, who followed much the same playbook, but didn't have Greta's slick PR team. But you are absolutely correct that a lot of people are woefully uninformed, misinformed, or just malignant. Or dare I say it, reality deniers. But again, $100bn a year at risk, and won't someone think of the grants?
Oh, you may also find this interesting-
In order to evaluate how much Total Solar Irradiance (TSI) has influenced Northern Hemisphere surface air temperature trends, it is important to have reliable estimates of both quantities. Sixteen different estimates of the changes in TSI since at least the 19th century were compiled from the literature.
This stuff usually gets glossed over in WG1, or given about 1 page by 1 author who is heavily invested in maintaining CO2 dogma. Hey Jo, where you going with that hockey stick in your hand?
Or course to suggest solar variability is heresy, because TSI is constant. Ish. Well, constant enough that it's variability is greater than the 'back radiation' from CO2's 4 absorption/emission points. 3 of which overlap with H2O, which is a more potent 'GHG'
And given CO2's spectrum has been known for a very long time, that kind of stuff is measureable and quantifiable. And even done by some orbital carbon observatorys that are basically flying spectrometers looking for CO2's emission peaks. And finding them in incovenient places, like over S.America.. And it's also possible to quantify spectral variations in solar output, which have all sorts of interesting effects on CO2, and photochemistry. And could also be rather important during a Grand Solar Minima.
But no. Anyone who committs heresy by denying official CO2 and TSI dogma must be uninformed and 'malignant'.. Even though scientists are supposed to be ojective and sceptical.
Oh, and riddle me this. We know the 'problem' is CO2's 'greenhouse' effect caused by 'trapping' heat. And we know the mechanism is based on the fundamental properties of CO2, ie it's absorption/emission spectrum. And this is quantifiable. It's done with instruments like the bandpass filter and spectrometer(s) onboard satellites like OCO-2.
So given that it's pretty easy to actually directly measure CO2's 'back radiation' via some simple, standard instruments... Where are they? And why do some climate 'scientists' still insist on using thermometers, wooden or otherwise as proxies when the exact quantities are, well, quantifiable?