Cheeky C(h)MIP (part 2)

Pilfering the CMIP6 atmospheric CO2 data

In the previous post in this series I promised we’d take look at the whole shebang from the year zero to the year 2014. Since the IPCC climate assessment reports are the evidence upon which globalists are building their plans, and since outputs from Earth systems models running under CMIP6 are what will be used to fill the next batch of reports, then we may argue that the single most important input variable in the whole of climate science (and thus our future lives) will be the reconstructed atmospheric CO2 record. Here’s what the IAC reckon this looks like:

That’s a right old tea-blurter, innit? At this point we might swear a lot and go round telling everybody we’re doomed. Or are we? The first thought that sprang to mind when seeing this hockey stick of hockey sticks¹ was: that’s an awful lot of unprecedented rise in CO2 to produce a warming of just under a degree in 100 years!

We don’t even have to resort to our trusty hand-held calculators to realise a shift of +120ppm CO2 is associated with a warming rate of ~1° per century. In percentage terms a 43% increase (400ppm/280ppm) in atmospheric CO2 has generated an 8% increase (14°C/13°C) in the mean global absolute surface temperature assuming, of course, that the theory of anthropogenic global warming (AGW) is a real and genuine thing and not some imagined garden path to globalism with fat grants along the way.

This means atmospheric CO2 has an awful lot more work to do if it is to push the global mean temperature to a level that could get uncomfortable. On this basis we’d need to see CO2 reach 520ppm (400ppm + 120ppm) for the globe to hit an anomaly of +2.0°C and 760ppm (400ppm + 360ppm) for the globe to hit an anomaly of +4.0°C, though this crude calc assumes a linear relationship, which it is not. I’ll be discussing the log-linear relationship between CO2 and temperature anomaly in a future newsletter, meanwhile have a squizz at this introduction and cogitate on the fact that a log-linear relationship means CO2 is becoming less effective over time.

Are humans capable of increasing carbon emissions for this to become a reality? Are anomalies of +2.0°C or even +4.0°C likely to seriously endanger anything at any point? We’ll be taking a look at these issues and more as we trundle along but for now I want us to consider that very flat early bit.

The Early Bit

This is what the early bit looks like if we stop at 1850 and totally ignore C20th Warming. This is an important period over which paleoclimatologists fight tooth and nail for the very good reason that the variation in temperature and CO2 we observe must be down to natural processes. Back when I listened to the geology teacher these were very real periods with all sorts of wonderful things happening like ice fairs on the Thames, vineyards being planted in Yorkshire and Greenland being settled by Vikings who took advantage of ice-free conditions. These days this is all politically incorrect speak for clever computer reconstructions by those whose grants push them in a certain direction reveal geology teachers prior to 1980 didn’t really know what they were talking about. Wiki says so, so it must be true. Anyways, here is the atmospheric CO2 reconstruction that is being fed into CMIP6:

Some of this makes sense in that it appears to support the greenhouse gas theory of global warming with the two warm periods showing hikes in CO2. Then there’s two declines sitting within the Little Ice Age. But it doesn’t all make sense. We’ve got a rise in CO2 during the Dark Age Cold Period and the Little Ice Age saw a dirty great hike in CO2. The Roman Warm Period also started off pretty darn low. Obviously we can’t have folk questioning the narrative, hence efforts like this (I wonder who funded that study?).

Squiggles To Blobs

Tracing all those squiggles whilst cogitating can make one giddy, so I derived epoch means and their 95% confidence intervals and ran out an error bar plot:

Whilst the epoch mean for the Medieval Warm Period supports the greenhouse gas theory nicely we have to raise an eyebrow for the Little Ice Age, whose epoch mean CO2 is way up on the Roman Warm Period. It’s also worth asking why we don’t see much differentiation between the Roman Warm Period and the Dark Age Cold Period (p=0.155, independent samples t-test for unequal variances).

Catching Our Own Tail

Obviously something else is going on to modulate the climate of the Northern hemisphere. Another awkward question we need to ask is whether we are looking at changes in CO2 as a result of changes in temperature. Back in HADCRUT Global Temperature Anomaly (part 1) we observed a seasonal rise in CO2 following a rise in temperature, positive feedback in the carbon cycle being a thing. So how much of what we are seeing here is feedforward and how much feedback?

If we use Earth systems models under CMIP6 to answer this question we’re getting a theory to prove itself, which is like a dog trying to catch its own tail. If we don’t use Earth systems models then we’re stuck trying to disentangle cause and effect using a muddle of real world data with everything related to everything else!

Next Up…

What would be smashing is to grab robust annual temperature records dating back to the year zero and look at the interplay with IAC’s rendition of atmospheric CO2. These do not exist and attempts at reconstructing such are riddled with assumption, being necessarily reliant on modelling technique, methodology, quality and quantity of samples etc. What I’m going to do next, therefore, is attempt to obtain some decent paleoclimatological temperature reconstructions and see what we can see. Until then…

Kettle On!

1. I think we can see now why that man Mann was terribly keen on producing a temperature graph to match.