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Polar Thinking


Launch of Ad Astra: An Illustrated Guide to Leaving the Planet by Dallas Campbell, 3rd October 2017. Moon goose by Emily jewellery. Photo by William Sutton.

This is a good news, bad news story.

I’ve been thinking about this theme a lot recently. So much of our energy is spent on categorising into opposites. Pro-Trump, anti-Trump. Brexiteers and Remoaners. Good, or evil. Asking questions about climate science in good faith, or in bad. Are you with us or against us? Are you on the right side of history or not? Climate change is all our fault, or it’s all natural. We’re screwed, or else there’s nothing to worry about. Climate sceptics are selfish and climate scientists are catastrophists. Black and white. Polar thinking.

The truth is, more often than we admit, somewhere in between. Fifty shades of monochrome. Greys might feel less safe, less clear, less defendable. But we know, really, most of us do, that climate change can be both natural and human-caused (mostly human right now).

Even more important is the ability to hold two apparently contradictory possibilities in mind – two poles – at the same time. My father was an art therapist, and in the book of his lectures and articles, “Ornithology for the Birds”, illustrated with the monochrome drawings of Thomas Bewick, he describes himself as “comfortable with ambiguity”*. Good intentions can lie behind bad behaviour, and bad behind good, and the future will be both worse and better than we can imagine. Opposites, absurdities, parallel universes. This is a different kind of polar thinking.

The ‘Northern Penguin’ by Thomas Bewick. Source: Wikimedia.

Two studies are published in Nature today. One that I led, about Antarctica, and another I contributed to, about Antarctica and Greenland. What’s the news? We want to know, impatiently – are things worse than we thought, or better? Is everything alright, or everything on fire? Concern or relief, belief or disbelief, share the link and close the browser tab.

Good news or bad news?


Date: Tuesday, 31 October 2017 at 20:51

Subject: Receipt of Nature manuscript 2017-10-14467

Dear Dr Edwards

Thank you for submitting your manuscript entitled “Reconciled model projections for the Antarctic contribution to sea level rise”. Your submission has been assigned the following tracking number: 2017-10-14467. We will be in touch again as soon as we have reached a decision.



2 November 2017

To: Suzi

Thought was IBS but felt bit different. Cramps after food. Totally lost appetite. Think for me was stress x


Our study is good news, of a sort, because we find that rapid collapse of the Antarctic ice sheet is much less likely than previously suggested. But, as one would expect from the words “collapse” and “less likely” being in the same sentence, it is not a simple story. It is one of caution, of weighing up the evidence, and of holding two apparently contradictory possible futures in mind: with collapse, or without. It is a story with layers of good and bad.

In March 2016, an extremely high-profile study by Rob DeConto and Dave Pollard predicted that Antarctica could contribute more than a metre to global sea levels by 2100, which would double projections for total sea level rise. They found this by incorporating a new idea into their model called Marine Ice Cliff Instability (MICI, “mickey”): a process of rapid, unstoppable ice loss caused by the continuous collapse of unstable ice cliffs along the coasts. They ran 64 possible versions of their model and tested them with reconstructions of the Antarctic contribution to sea level from the mid-Pliocene (3 million years ago) and last interglacial (around 125,000 years ago) – rejecting any that failed the tests. Pliocene sea level is, understandably, very uncertain. So they used two possible ranges: 5-15 m, or 10-20 m. The second choice led to their highest predictions for the future: a mean sea level contribution of up to 114 cm by 2100 under very high greenhouse gas emissions. And this so-called ‘ice apocalypse’ has been debated in the science community and sometimes in public ever since.

I started plotting the data just a few days after it was published. Starting a research visit to Grenoble, I saw they had put the results in the Supplementary Information, and I wanted to compare them with our 2015 study. I immediately noticed a strong sensitivity to the lower bound of their ‘high’ Pliocene test (10 m) that had led directly to those metre-or-higher predictions. And only 15 of their 64 model versions had passed that test, meaning the sample was small…but because those versions were similar, the uncertainty looked relatively small.

I was gripped. Did people realise the sensitivity of the ‘one-metre’ results to this choice? Could we improve the analysis and estimate something more robust?


Date: Tuesday, 12 December 2017 at 19:19

Subject: Receipt of revised Nature manuscript 2017-10-14467A

Dear Dr Edwards,

We are writing to let you know that Nature has received your manuscript entitled “Reconciled model projections for the Antarctic contribution to sea level rise”, and the editor will be in contact in due course.


Date: December 19, 9.25 PM

Hello Mum!

Unfortunately this IBS has been intermittently quite bad…did I tell you it was very painful when I went to Hastings? I was pretty incapacitated…then again yesterday (though better today). The GP is doing various checks but thinks it probably is just IBS and told me to increase the laxative dose and drink more water…!! I am also trying magnesium (Jane’s recommendation – also has a rather…er… powerful effect…) and probiotics (just the ones with decent effects above placebo in randomised controlled trials of course…). … If the holiday doesn’t cure it I will think of a plan B…


Rob DeConto kindly began to run new simulations, so I could do the analysis I wanted.

That summer, I wrote a talk on the course theme ‘Ice and Fire’ for the Champernowne Trust art therapy summer school that my father directed for over 30 years. It was the first time I really felt able to bring together my work in science and my family background of art. I showed images and told stories of surprises and contradictions in the natural world. That ice flows, ice harbours life, and fire can protect. That ice can burn.


Methane hydrate. Source: U.S. Department of Energy.


January 10th 2018 10:34 PM

Hi Mum,

Thank you for the nice card, the lovely bath salts – and the silly postcards! I have been having 2 baths some days, so that will be lovely.

Right now I’m feeling great. I started taking Tramadol last night (!) and it has got rid of most of the pain. My muscles are also more relaxed and I think even the number of cramps has gone down. I slept a bit better last night and think it will be even better tonight. Tonight I had a whole bowl of Rice Krispies!


19 January 2018 21:33
To: Greg and Maddie

Hey guys I found the reason for the stomach cramps that were troubling me that night of the Christmas drinks….Bit of a “bad news good news” one… A tumour in my colon. Probably was cancer but they expect it to have been cured as it looked very self-contained. Found it last Friday and operated next morning. I feel really happy to have it sorted and recovery is also going really well. Am in hospital a few more days then 2 months off work to recover xxxx


Hi Tamsin. Just woken up over here. Gosh that really is bad news good news. Blimey.


By February 2017, Rob had sent me the last bit of data, and I made good progress on the analysis during another Grenoble trip that spring. I could now use statistical methods called ’emulation’ to mimic their model and fill in the gaps between their 64 simulations. With my co-authors, we started to look at the sensitivity to different assumptions. What happens if we test the model with satellite data, instead of data from the Pliocene and last interglacial? Is it justified and robust to use such a high range for the Pliocene?

Story #1: The bad news (that could have been worse)

We found the Antarctic contribution to sea level this century is smaller than implied by DeConto and Pollard’s study. They had shown mean values ranging from 64 to 114cm, but our most likely value is only 45 cm. This is still definitely bad news, and we also couldn’t rule out values much higher than this. But we found the balance of probability leaned towards much lower numbers than before.


Mar 13, ’18 1:02 PM

Subject: Update: FOLFOX 1

FOLFOX 1. Hooking me up to chemo drugs for my first cycle. Short version: very tired, but otherwise a pretty good first 24 hours EXCEPT Magnums now taste horrendous.

First chemo infusion.

Date: Wednesday, 14 March 2018 at 18:00

Receipt of revised Nature manuscript 2017-10-14467B

Dear Dr Edwards,

We are writing to let you know that Nature has received your manuscript entitled “Reconciling model projections for the Antarctic contribution to sea level rise”, and the editor will be in contact in due course.


Now for the clever part: we could ‘switch off’ the MICI feedback in the emulator. Could it still pass our three tests? Pliocene, last interglacial and the satellite era? Yes.

Story #2: The good news (that is still pretty bad)

We found that including MICI is not necessary to explain the past, and therefore it might not be present in the future – at least, we don’t have much evidence to support it yet. Leaving it out gives much smaller sea level contributions: a most likely value of only 15 cm, one metre less than the highest projections of DeConto and Pollard, and a 5% probability of more than 39 cm.

But this is still bad news. If Antarctica contributes this much to sea level this century, it’s more than the predictions of the IPCC in 2013, and certainly high enough that we need to adapt.


Our two storylines are shown below: Story #1 shows the sea level contribution with ice cliff instability (bad, but better than DeConto and Pollard’s estimate), and Story #2 without the instability (much better, but worse than the IPCC in 2013).


Predictions of the sea level contribution from Antarctica at 2100 under very high greenhouse gas concentrations. The red curves show our estimates of the probability of different values, with and without the cliff instability hypothesis (the peak shows the most likely value). The grey bar shows the IPCC (2013) ‘likely’ (66% or greater probability) range. The blue bar shows the DeConto and Pollard (2016) mean and spread for their highest projections. Image created by Melissa Gomis, IPCC Working Group 1 Technical Support Unit.


9th July 2018

FOLFOX cycle 9 of 12


Date: Monday, 9 July 2018 at 19:20
Subject: Receipt of revised Nature manuscript 2017-10-14467D

Dear Dr Edwards,

We are writing to let you know that Nature has received your manuscript entitled “Reconciling model projections for the Antarctic contribution to sea level rise”, and the editor will be in contact in due course.


Date: Aug 20, ’18 10:22 AM
Subject: FOLFOX 12: On fatigue, fingers and finishing

A very long time since my last update…and this morning I’m at the UCLH Macmillan Cancer Centre for my last chemo cycle.

Chemo fatigue is utterly exhausting – no matter how much sleep, you rarely feel rested – and affects my cognitive abilities and emotions. For me it has been:

  • Slurring, missing and swapping words when I speak
  • Pain in my eyes and eye sockets, and general body aches
  • Feeling I can’t make it up stairs, or put tights and shoes on
  • Sleeping 12 hours, but feeling rested for only 1-1.5 hours after
  • Nearly walking in front of cars; forgetting more, and more seriously, than usual
  • Swaying, staggering and stumbling as I walk; dropping things more often
  • Brain becoming completely blank as I stare at pans burning on the hob, or try to remember basic things
  • Feeling panicky and vulnerable, especially if the fatigue gets worse while I’m alone outside the house – feels like being a 6 year old suddenly losing sight of their parent in a busy supermarket
  • Getting extremely upset if I go to bed too late or wake too early
  • Taking 1-2 naps/rests most days, including on the floor of someone’s office at Jodrell Bank, on a row of chairs during a meeting in China, and on a low wall in the Eden Project (I’m lucky that I don’t feel embarrassed asking/doing these…)

7th September 2018


A surprise gift via an anonymous climate sceptic.

Sunday, 23 September 2018 at 19:37
Subject: Receipt of revised Nature manuscript 2017-10-14467E

Dear Dr Edwards,

We are writing to let you know that Nature has received your manuscript entitled “Reconciling model projections for the Antarctic contribution to sea level rise”, and the editor will be in contact in due course.


Date: Thursday, 6 December 2018 at 20:59
Subject: Receipt of revised Nature manuscript 2017-10-14467F

Dear Dr Edwards,

We are writing to let you know that Nature has received your manuscript entitled “Revisiting Antarctic ice loss due to marine ice cliff instability”, and the editor will be in contact in due course.


The other paper, led by Nick Golledge, is more about the bad news. Meltwater from the two ice sheets seems to have more impacts on the global climate than we thought: greater variation in temperatures, a weakening of the North Atlantic ocean circulation, and amplifying the ice loss from Antarctica.

But could there be a grain of good? It’s another brick in the wall, another piece of the puzzle showing that things are complex and surprising. It’s another piece of evidence that strengthens our understanding of the world and the risks we face – and how much difference it would make to reduce future emissions.


Date: Friday, 4 January 2019 at 15:38

Decision on Nature manuscript 2017-10-14467F

Dear Tamsin,

We are delighted to accept your manuscript entitled “Revisiting Antarctic ice loss due to marine ice cliff instability” for publication in Nature. Thank you for choosing to publish your work with us — and for your patience during the long review process!


24 Jan 18:19

To: Georgia

I am feeling much stronger, healthier, more clear headed.


29th January 3:28 PM

To: Tamsin

Cancer survival can be a life changing opportunity for good. Despite the physical damage done by chemo, looking at the changes I’ve made to my life, I’m actually glad I developed cancer.


To: Michael

I agree that if I have no recurrence I’d rather have had it


I can’t unravel our Antarctic paper from my own year of bad news, good news. The lead-up to my diagnosis on the 12th Jan, the treatment, the slow recovery. I blamed my first symptoms on stress when first submitting and changing jobs. I resubmitted just as I started to get so ill that I missed days of work and cancelled Christmas plans. I resubmitted the day after starting chemotherapy; my oncologist Dr Shiu mentioned it in my medical notes. I resubmitted on the day of my 9th chemo infusion, through a growing haze of chemo fatigue. I resubmitted three weeks after finishing chemo, the day before term start, as I fought to get my brain back. And finally in December, a week after taking some leave for exhaustion. The paper was accepted after the Christmas break as I started to grow stronger.

As I search for a link to my Dad’s book for this article, I catch my breath at this quote from a review:

“Rejection of reductionism and fundamentalism made [Michael] Edwards a champion of soul, a challenger of simple mindedness.”

A champion of soul, a challenger of simple mindedness. The anonymous climate sceptic that sends the kindest gift to a climate scientist. Cancer survivors sharing their gratitude for a life-changing illness. A penguin that lives in the north, a goose that migrates to the moon. My future holds two opposites: the cancer comes back, or else it doesn’t. I know the probabilities, roughly. I catch myself making plans with and without more treatment. Two contradictory possibilities in mind. On ice, or on fire. With collapse, or without. Polar thinking.


“We thank K.-K. Shiu and D. Campbell for supporting T.L.E. in this work.”


* I would give the page number of my Dad’s quote, but I can no longer find it, so perhaps I imagined it.

  1. Thank you! I have yearned for multiple perspectives to be woven well into a single voice, and here it is. I wish you would write about everything! Here is hope as a wisp of sky and earth-sheathed iron.

  2. Tricky piece to write, I guess. Goodonyer.

    I wonder about the appearance of polarisation in public discourse – ask a binary question, get a binary answer. How much apparent polarisation is down to the questions posed by newshounds or by pollsters? Or to vocal proponents of extremes? To illustrate with Brexit, I voted to remain, but if I had three votes, I would have cast two for remain and one for leave, to express a balance between the positive nature of the Euro-project as a whole (post-war peaceful coexistence and the like) versus the … er … clumsy nature of aspects of its operation. And on the odd occasion that I give public lectures (amateur Geol Socs, local WI, sort of thing) I usually get a sane and interested response (as well as the odd cake), and thus far no instances either of alarmism or of denialism in the audiences.

    You are far more widely engaged than me. What’s your impression of the appearance versus the reality of polarisation?

  3. I had no idea you were going through this. I have until recently followed your work, admittedly, rather
    Intermittently. I am thankful there is good news in your personal story and appreciate your focus on understanding as much as possible what is happening in Antarctica.
    Beautifully written and a telling tribute to the influence of your father!

  4. Dear Sheldon,

    It was – thank you.

    Good question. Either way, I think we know fairly well that the more we push people the more they double down on their views and become entrenched in that polarisation. I suppose my views in some ways are not surprising – that meeting in person can be more successful in finding common ground than talking online (but not always). Less common perhaps is a commitment to acknowledging the truths, wisdoms or partial agreement in what ‘the other side’ say, as you do for Europe. And finally, less common still, is to assume good faith unless actively demonstrated otherwise (and I have a pretty far barrier for that, because I assume people usually believe they are acting in good faith in accordance with their own values and aims). There is a more hardline view of this around the extent to which individuals can be considered evil or bad at all, but I’m not confident in trying to express it on a blog comment while tired. Over a pint, perhaps.


  5. Thank you for opening your heart, for putting a very human face on what must by necessity be (and be seen to be) dispassionate scientific research. But mostly, thank you for reminding us that cognitive dissonance might be uncomfortable, but it’s also a mark of our humanity.

  6. Thank you for having the courage to write this. I’m going to give it to my teenage daughter for (hopefully) inspiration.

  7. Hi Tamsin

    As a survivor (male, 63, breast cancer), I can agree that sometimes ones worldview changes for the better from the big ‘C’ experience, certainly 2.5 years on I’ve lost 20kg, exercise more frequently and very much enjoy my 18 month old grandson that I might never have seen…

    If you need cheering up I suggest reviewing the linked article, of course Correlations ≠ Causation but sometimes they can be amusing…

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