Actually I made two

In a break from normal programming, I would like to present a humble artistic offering. A picture paints a thousand words, a bad picture anyway, so art of course has a way of short-circuiting the need for laborious explanation.

Some time ago, Professor Sir Doctor Admiral Hawkins came up with a striking image, which represented the rapid cooking of the Earth in the form of a series of stripes of reddening hue. The presentation has already been criticised as unscientific – for example by John in Alan’s post here. The great man received an award for his work, which was richly deserved (obviously that comment is a little saccharine thanks to implied sarcasm, but one presumes that the MBE wasn’t just for the stripes). I was going to say that the award was presented by the Chinese Communist Party, but our lawyer began to stare at me with his beady eye while twirling his moustache, so I relented. In any case no-one could seriously have believed such a comment to be anything other than a poor attempt at a witticism. And although our Chinese communist friends (Hi guys! Thanks for dropping by!) are watching the West’s self-vivisection on the green altar with grave concern, one can point to the fact that thanks to their co-ownership of Dudgeon wind farm to name but one they currently at least, by sheer coincidence, benefit from our madness. But Prince Charles (bestower of the award of an MBE on the artist) has no such mossy skeletons in his compendious and supernumery closets.

I had threatened to create my own version back then, but the wall shrugged (it didn’t shrug – it just sort of stood there with an indifferent expression). Anyhow the time came that I decided to make good my threat.

Times two.

My first attempt at a stripey work of sceptical climate art was based on a re-scaling of the original. Instead of covering one and a bit degrees, the global surface temperature anomaly of the globe over the past 170 years centred on 35 years ago, I made my set of stripes based on a scale whose extremes are the hottest and coldest places on Earth. Key below:

The result is predictable perhaps, but rather anodyne. We’re firmly in the pink.

Well, it was back to the easel in terms of finding something even modestly pleasing to the eye. In Denierland (copies of which are not available at your local bookshop, but the proprietor might be able to find you one, although I would whistle for Mr. Bezos) I presented a rather bad figure showing estimates of carbon dioxide concentrations over the Phanerozoic era, or the beginning of the Devonian onwards anyway, from the trove of data compiled by Foster et al in 2017:

Not very pleasing to the eye. But it seemed to me to offer some opposition to the claim in their title, which was:

Future climate forcing potentially without precedent in the last 420 million years

I also presented a rather unwieldy CO2 wiki:

While functional, in order to fill the page both axes are in fact the same. Unsatisfactory artistically-squeaking.

So, I wondered how a figure of CO2 over geological time would look if represented as a series of stripes after the fashion of Ed. The answer is of course that the way it would look is entirely determined by the choices the artist makes re: colour palette, scale and positioning. I chose more green for more CO2 up to the highest value in the series (about 3000 ppm) because plants like CO2 (that is a fact, so do feel free to check it). Values below the much-idolised “pre-industrial” level of 280 ppm are in increasing opacity of red the lower they go. Below 150 ppm, everything goes a sinister flat grey because at that concentration the plants, and the rest of us, are at risk of dying out altogether. Each bin, each stripe, represents 2 million years. The value for each stripe is the simple average of the CO2 estimates within that bin. So this is not remotely a valid approach for a metastudy. It gives the same weight to values based on one data point as it does to values based on a hundred data points. Some of the two million year bins have no data, and are missing (the adjacent ones are simply butted up next to one another, rather than using interpolation or leaving gaps). Nor can the colour scheme be described as scientific. But hey. If you don’t like it, tell your momma.

The key looks like this – note the annotations from the original CO2 wiki:

And the stripes themselves look like this:

The point I would like to make with my stripes is this. The present concentration of CO2 in the atmosphere is not, repeat not, unprecedented in Earth’s history. Nor will it be unprecedented when the concentration reaches double pre-industrial, 560 ppm, which it certainly will in due course (my estimate in Denierland was that we would reach that point in 2061, based on an extremely naïve model). The simple average figure for CO2 concentration since the Devonian is 750 ppm – a level that may be hard for us humans to achieve in the absence of a large-scale renaissance in coal. Far higher levels have been reached in the past, and life on Earth did not perish in those times. It thrived. Anyone who tells you that our emissions of CO2 are an existential threat just hasn’t looked at the available data.

Here are the stripes labelled up a bit:

Do feel free to cut, paste and share. In a very real sense, these stripes belong to us all.


Foster, G. L., Royer, D. L., & Lunt, D. J. (2017). Future climate forcing potentially without precedent in the last 420 million years. Nature Communications, 8, 14845. Available with a swift search of the interwebs.


  1. Wow, the dark mode version on the Cliscep home page is awesome. Something to do with the way it handles the covering text? Anyway, it beats my version. Looks kinda like sommat out of The Matrix.

    Liked by 1 person

  2. Heh Momma, I don’t like JIT’s stripyness. CO2 down to only 50 ppm for two million years when during this time – the Late Carboniferous and Permian the majority of the world’s coals formed. Difficult to believe.


  3. Hi Jit

    Was there a reason you didn’t simply replicate Hawkins’ hatchings but use the palette of colours below to represent how our globe has become more benign?

    We already know extreme cold kills maybe 7x – 15x more victims than extreme heat.

    Liked by 1 person

  4. By which I mean we should present the stripy coloured version of the decreasing death rate due to extreme weather.

    Liked by 2 people

  5. By the way, I recommend a reading of Denierland (well, several readings, actually – there’s lots of good stuff that might be missed first time round). As I said to Jit when I first read it, it’s the book I wish I’d written, and which I might have done had I been more methodical and better-organised. It deserves to be more widely known.


  6. JR – or simply replicate Hawkins’ temperature hatchings, but use the above (or similar) colour palette of blues & greens rather than blues & reds.

    After all, Hawkins’ temperature hatchings makes no acknowledgement that there MUST be a global ‘optimum’ temperature!


  7. This should be Joe’s version of my emulation of the original. It probably doesn’t use the same data – I think mine is v4.6 of Hadcrut. It stops in 2019.

    Liked by 1 person

  8. John’s request is a little harder to fulfil, but I’ll look into it. It depends if the data is available by year: by decade, there won’t be many bars.


  9. Alan, there were two data points in that 2 million year bin, one of 47 ppm and one of 50. They came from:
    Montañez, I.P., Tabor, N.J., Niemeier, D., DiMichele, W. A., Frank, T. D., Fielding, C. R., Isbell, J. L., Birgenheier, L.P., and Rygel, M. C., 2007, CO2-forced climate and vegetation instability during late Paleozoic deglaciation: Science, v. 315, p. 87-91. (Don’t know if this is available to those of us who aren’t in an ivory tower.)

    However, the data I plotted is the mean of the values reported by Montañez et al – it’s a column of data provided by Foster et al. Looking more closely, there is a separate column for “reported” CO2 rather than “mean” CO2. The “reported” values given in Foster et al are 190 and 158.

    The arrow points to the bin between 294 and 296 million years ago, and although it is labelled “end of the Carboniferous”, it’s actually into the Permian. As to where the CO2 went, maybe it became coal because there was no fungus to decay the dead trees…


  10. JIT. My objections are the result of the presence of abundant coal in the Upper Carboniferous (=Pennsylvanian) and Lower Permian. Those prolific coal-bearing periods have always been associated with periods when atmospheric carbon dioxide levels were high. Levels below 100ppm CO2 would have been associated with periods with vegetative die-off.


  11. If the very low CO2 values come from the Early Permian, then how to explain the Gondwana coals of this age or the fact that the Late Carboniferous-Early Permian extinction frequency was relatively low? The significant end Guadalupian extinction event (= Olson’s extinction) occurred towards the end of the Mid Permian.

    The main reason for objecting to a very low Early Permian (or in fact any other low CO2 event within the Phanerozoic) is that it would cause the death of (most? all?) plants, and therefore of all animals. This clearly never happened.

    Thanks for your source references. I may attempt a visit to UEA’s library to consult.

    Liked by 1 person

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