My New Improved Sceptics’ Version of Ed Hawkins’ Stripes

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.

via Climate Scepticism

May 17, 2022 at 12:41PM

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