Month: January 2023

Politics, history, science and the continuation by other means

War is not merely a political act, but also a real political instrument, a continuation of political commerce, a carrying out of the same by other means. All beyond this which is strictly peculiar to War relates merely to the peculiar nature of the means which it uses. 

Carl von Clausewitz, On War

I have lots of thoughts about this really great Timothy Snyder piece on the US 2016 elections, (not least, I wonder what it means for how we understand Brexit too?)

But most of all I’m reminded of Gary Kasparov’s declaration that the point of modern propaganda is not to make you believe something but it’s to make you believe nothing. (I paraphrase slightly). Much of the piece is about how the Russian propaganda operation as been so successful at engendering doubt about Ukraine and the state of relations between Russia and Ukraine.

I sometimes feel the invasion of Ukraine has really been a wake-up call for many of us because it’s just so undeniable. An actual event happening to real people that we know with a pretty clear narrative. The genius of Russian influence operations has always been to muddy the waters sufficiently that it was a little hard to trust anything that anyone said or wrote.

In this sense I’ve also found Timothy Snyder’s series on the making of modern Ukraine (which I’ve been listening to over the last few weeks) brilliant and helpful and interesting. The subject is fascinating, but it also because it becomes clear listening to a historian that, yes there can be different ways to interpret events, but the events themselves are real and we have a duty to try to learn the facts before judging them.

This is of course exactly how scientists should think, that we have to establish good observational data before trying to interpret it. We also need, inevitably to consider what are the uncertainties and likely range within that data. What is missing? What can’t we know? What is the most likely interpretation based on the things we can observe? How reliable are our measurements?

One of my favourite teachers at school who really helped to develop the way I think was very clear on how to do this. And he was not a scientist, he was a historian.

Ultimately, I was more interested in understanding the physical world and went on to study glaciers, ice sheets and the climate system at the poles. However, as I’ve been focusing more on sea level rise and how on earth we adapt to a changing climate it’s quite clear that going back to the social sciences will be important to understand human behaviour. And the murky way other actors seek to influence us as we adapt to climate change is also going to be important to understand. There has been undue influence from a “Merchants of Doubt” perspective for sure for many years when it comes to the causes of climate change and the effects. This is very clear in the mess of climate denial that the new Lord of Twitter has unleashed, it’s a little bit like returning to 2009.

But here we are in 2023 and there are apparently serious politicians having hissy fits over the idea that a significant source of indoor air pollution should maybe be replaced with a far more efficient alternative (yes I’m talking about replacing gas stoves with electric induction), imagine how climate adaptation can be weaponised just as for example COVID vaccination was as part of the culture wars?


Anyway, this is a bit incoherent maybe. But it’s a great piece for clarifying what we know now and maybe for working out what comes next in terms of Russian interference in democratic institutions. And from a climate scientist perspective it’s also another reason to try to avoid (if we can), becoming just another cultural battleground. This is also key: it’s not always about money, sometimes people really are being manipulated for other reasons:

“When people act in the interest of a foreign power, it is sometimes for money, it is sometimes because the foreign power knows something about them, it is sometimes for ideals, and it is sometimes for no conscious motive at all — what one thinks of as one’s own motives have been curated, manipulated, and directed.  It seems quite possible — I raise it as a hypothesis that reasonable people would consider — that some mixture of these factors was at work at FBI New York in 2016.”

Well worth reading the whole thing.
https://snyder.substack.com/p/the-specter-of-2016

Danish Antarctic Science

Historically Denmark has not done a huge amount of Antarctic science. We are the only Nordic country (apart from Iceland) without an Antarctic station for example, but quite a lot of research has been done in collaboration with other countries. Of course you could argue that with our natural focus on Greenland and the Arctic, we don’t really need one…

The threat of sea level rise, with a large portion coming to Denmark from Antarctica has rather focused our minds on down south though and on this basis I now have several research projects with an Antarctic ice sheet and climate focus, including PolarRES, PROTECT and the just started OCEAN:ICE – I will write more on all of these at some point.

Of course it’s not just my employer DMI who knows that in spite of being far away, the coldest, driest, windiest continent is important in the global system and especially to Denmark in a sea level rise perspective. We have also been monitoring ozone and sea ice for decades and making ice charts for navigation when required also.

The Danish Technical University have also been flying remote sensing missions in Antarctica for decades and the Niels Bohr Institute have been involved in several big ice core projects, including the oldest ice core currently underway. GEUS and Aarhus University have geological interests and there are various biology research programmes underway too, while the IGN have a project using old soviet spy satellite imagery that sounds like a plot from a cold war novel…

All of which is to say, it’s time for a small get together to find out who is doing what, going where and when and who would like to plan and collaborate together on new and exciting projects.

The Danish Antarctic Science seminar, an annual event, will be held on the 2nd February at DMI this year and online. It covers all sciences, not just climate and ice sheet and this year we’d really like to get a broad group representative of the full spectrum of polar science in Denmark, so do feel free to register and listen in and discuss, even if you have no active or inactive projects in the Antarctic.

Let me know if you are a danish – based scientist and would like to come along or if you are otherwise interested and we’ll see what can be arranged. Deadline for registration is the 30th January!

Ses.

Crane Glacier on the Antarctic peninsula from Sentinel 2 satellite imagery, processed on snap planet

Rules of thumb about ice sheets and sea level rise:

One of the advantages of being part of a research institute are the fascinating conversations that happen over lunch between colleagues working in different areas. Today was a classic with conversation ranging from the stratospheric effects of the Hunga-Tonga eruption to the different types of snow crystals that form in snow packs and their impacts on sea ice. However, the conversation started with a request to me for some rules of thumb on sea level rise, so here they are:

The Greenland ice sheet loses on average around 250 to 280 Gigatonnes of ice each year – that’s from all processes including melt and surface runoff, iceberg calving, basal melting and submarine melting.

It varies a bit from year to year but over the last 26 years the ice sheet has either lost ice or been neutral (and it’s had very few neutral mass budget years).

Change in mass of the Greenland ice sheet from the GRACE and GRACE-FO satellites since 2022

The Antarctic ice sheet loses on average about 100 Gigatonnes of ice net each year (probably) from all processes, it receives about 2000 to 2500 Gigatonnes of snow (depending a bit on where you measure Antarctica to end) whereas Greenland receives around ~700 gigatonnes of snow.

The small glaciers and ice caps around the world contribute a bit more to sea level rise in total each year than each of the big ice sheets currently, but they will be quickly exhausted. As there are thousands of small glaciers, most of which are not well monitored, we have to estimate how these are changing using models. It appears that on avergae they add around 0.7 to 1 mm of global sea level rise each year.

Glacier changes are not well measured at most glaciers but this analysis from Copernicus is based on a few that are in Europe.

The thermal expansion of the oceans is still the largest part of currently observed sea level rise but on an annual basis, the cryosphere now often contributes more.

As I’ve elaborated on before, 1 Gigatonne of water is hard to visualise, it is a cube 1 km long, 1 km wide and 1 km high and about 360 Gigatonnes (or km3) raise global average sea level by 1 mm, so Greenland contributes around a half to three quarters of a millimetre to global sea level every year. My old friend Lindsey Nicholson at Innsbruck University has a cool blog (which you should check out here) and shows this visualisation if it helps..

What a gigatonne looks like, visualisation shared by Dr Alex Gardner, JPL from this talk on glaciers and sea level rise

Since the early 1990s sea level rises about 3mm every year, but over the last 5 years it has been closer to 4.5mm per year. The curve over the last 2 decades has followed a quadratic shape rather than a linear shape – put simply, this means sea level is accelerating. The sea rose 10mm from January 2020 to August 2021.

Global mean sea level rise since the early 1990’s as shown in the WMO state of the climate report 2022

An El Nino, which some are warning could occur this year, may cause a temporary pause or at least slow down in sea level rise, even as global air temperatures increase, mostly due to the large amounts of rain that are associated with it, but this will only be temporary.

While the rate (3-4 mm per year) doesn’t sound like very much, every mm counts, increasing the risk of coastal flooding and storm surges affecting coastal communities.

Finally, global sea level rise is not distributed evenly, broadly speaking, the further away from an ice mass you are, the more likely it is to affect your local sea level, so Greenland matters less than Antarctica in Northern Europe.

NOAA’s visualisation of observed sea level rise from satellites in the background and at tide gauge locations (the round dots) since 1993, note the uneven pattern which reflects processes like ocean currents, atmospheric circulation and winds, local relative land movements and gravitational changes due to changing ice masses.

I hope these little rules of thumb help. Feel free to add more (or disagree) in the comments..

The expedition frame of mind

We will head to the field in Qaanaaq in late March with various instruments.

Update: It’s official now, I have booked my tickets, we have new instruments to deploy and a colleague and I are working on developing a new programme that we can hopefully also fit in alongside the currently planned programme. More on this at some point no doubt. The countdown has begun and I am getting into that fieldwork frame of mind.

I came across this blog post from old friend and former colleague, Karen Darke, who I’m now more or less out of touch with, unfortunately.

She is just back from her incredible Pole of Possibility expedition in Antarctica and she wrote this which I think perfectly summed up that expedition frame of mind..

It’s a really great blog post and well worth a read of the whole thing.

There are people and places I look forward to again but my soul is already grieving for expedition life, for the dualities that it brings: complexity and simplicity, space and confinement, alone-ness and together-ness, vulnerability and strength, connection and disconnection. I miss waking up huddled closely with my tent-mates and the time skiing silently in big open white-scape. I miss the detailed organisation of kit and systems and the contrasting uncertainty of every hour of every day. I miss feeling small and vulnerable as well as strong and capable. I miss the clear, invented purpose of every day.

Karen Darke, Pole of Possibility
One of those moments on a fieldwork expedition when everyone is busy, drilling holes in the ice to send down a CTD, drilling a sea ice core to measure salinity, digging snow pits, deploying instruments. My DMI colleagues Steffen Olsen and Andrea Gierisch are the ocean and sea ice scientists driving this work in close collaboration with our Greenlandis friends, you can read more about their work here: ..

Our fieldwork expeditions are maybe a bit more frenetic than the pole of possibility has been (in some ways, probably not others). We are always racing against the clock and the weather to get as much work done as possible. We probably cover less distance and there is perhaps less physical stress as the dogs do the hard work of pulling, rather than skiing with human muscles. Nonetheless, there is a constant low-level thrum of thinking, planning, checking. Even if there are also often whole hours, where not much other than travel happens and that are extremely valuable thinking time. (And how often do we get that in the modern world?)

Unlike the Antarctic, working with local people in Greenland means that we also see the landscape as a working place, not just a white desert far away and as Karen writes, how true this is:

It is harder than we anticipated to leave, but Antarctica has been a reminder that we are adaptable, resilient, purpose-seeking, capable humans. No matter how harsh our environment may be, we seem to find ways to connect, collaborate and create ways to not only survive, but to thrive.

On a slightly different note, I had momentarily similar thoughts to Karen on the problem of despoiling the landscape with toilet visits the first time I visited Qaanaaq, before realising that when travelling with 30 dogs (as the local people have always done), the problem is rather moot. But as I have written before, it’s easy to fall into the trap of pristinism in the Arctic. Our work on the Arctic environment is a reminder that it really isn’t. Even in Antarctica, environmental pollutants from lead to microplastics have been found, while the curse of overfishing is almost as visible in the Southern Ocean as in the northerly just as climate change is also taking a toll.

But finally, I also find myself fully agreeing with the last part, because although fieldwork is often cold, uncomfortable, difficult, exhausting, boring and tiresome, it’s also often fascinating, rewarding and exciting. And the experience can change us.

Just as a photograph can’t always capture the profundity of a place or a moment, it is sometimes difficult to find words that describe how something has sculpted us. An experience can impact us so deeply that we don’t immediately know how to translate it for others. And may never

I am immensely privileged to be able to do fieldwork in Greenland and I am extermely grateful for the opportunity to do so.

The vanishing of the ice…

I was recently asked to comment on this interesting new paper by David Rounce and co-authors for AP by Seth Borenstein called “Global glacier change in the 21st century: Every increase in temperature matters”. You can read his resulting summary here . I’m posting here the slightly expanded and lightly edited response I sent to Seth in response to his (very good) questions.

The authors only look at the small glaciers and ice caps in this study, not the big polar ice sheets, though they do also cover small peripheral glaciers in Greenland and Antarctica that are not part of the main ice sheets. Of course, this means that sea level rise from all the other important processes like thermal expansion and ice sheet met also have to be taken into account on top of the numbers given here.

Their main findings were that at 1.5 °C above preindustrial, we can expect total glacial mass loss between 2015 and 2100 would be 26% with 90 mm of sea level rise and 49% of the small glaciers and ice caps lost globally. The paper only deals with these small glaciers and does not count the big ice sheets!

At 4°C, we’re looking at 41% mass loss with ~154 mm of sea level rise and 83% of glaciers lost. At 2.7 °C, where the world is now heading, 32% mass loss, 115 mm of sea level rise and 68% of glaciers lost.

I’m sad to say that the results aren’t exactly a surprise – the community has known for some time that the loss of glaciers is basically linear with temperature, so the title of the paper is really spot on, every tenth of a degree really does matter. This earlier paper by my Horizon 2020 PROTECT project collaborator Ben Marzeion shows something very similar But it’s a nice new result with the latest generation of glacier model and updated with the latest CMIP (IPCC) scenarios and they included some new processes that weren’t very well accounted for in previous work.

My first thought was that these latest estimates were actually a little lower than I expected, but the baseline in the paper is 2015 – we should remember that many of these glaciers have already lost quite a lot of ice (see my two photos of Nigårdsbreen in Norway, taken only 13 years apart) – so the new estimates are basically in line with what I would have expected given earlier work. I’d also expect that they will continue to lose ice beyond 2100 so it’s definitely not an end state that they are giving here. As they state in the article there will be widespread deglaciation of some pretty iconic parts of the world, even under the present planned emissions reductions..

In many ways part of the problem has been the previous studies have not always accounted for all the processes: frontal ablation (melt and calving of vertical ice cliffs, mostly in contact with water), the effect of debris cover and so forth (the latter will likely reduce the rate of loss, the former probably increases it). Given what we know about these processes and how to represent them in models, I still consider this work to be a more realistic estimate. Then we also need to account for the climate models and the scenarios used to force them – there are some important differences between CMIP5 and CMIP6 which might also account for some of this shift.  We have actually seen something somewhat similar for the projected changes in the big ice sheets.

It’s probably important to remember though that this study still needs to make simplifications, especially when looking at so many glaciers in so many different regions, so there will always be new updates to come with improved computing power and computational techniques and better representation of processes. Having said that, I do not think the picture will substantially change in future, though I can always be proved wrong, and the glaciers community are now at the stage of refining estimates for rates of mass loss.

Globally the loss of glaciers means sea level rise. Regionally and locally the biggest consequences will be for for water resources and we’re likely to see a local increase in natural hazards like outburst floods and avalanches that will need to be carefully managed. There have been a couple of instances already in the last year or two that probably demonstrate this well (e.g. the Marmolada glacier in Italy last year).

Sea level budget divided into components, from Legeais et al. 2018 ESSD The steric component is the expansion of sea water as it warms.

The small glaciers are currently a larger contributor to sea level rise than the big ice sheets, but that will of course change as they disappear and even small amounts of sea level rise, as represented here, are important in coastal communities where storm surges can occur. So we definitely need to account for their loss in planning for sea level rise and extreme storm surges. Locally and culturally there will also need to be changes. I think this will be a little traumatic for some cultures which have always considered themselves “glaciated” nations. The response I see to pictures  of the current state of the European Alps where people are skiing on artificial snow in green fields is a case in point here. It’s a shocking thing to witness.

I include myself in the group who has to get used to the cultural shift.  I have worked on glaciers in the Alps and Norway which are really rapidly disappearing. It’s kind of devastating to see, but it’s not actually surprising. We have known it was coming and in many cases (including the authors of this paper), measured the massive losses (last year, 2022 was a disaster for the Alps and both Fabien Maussion and Matthias Huss who are co-authors on the paper are running very comprehensive programmes that show in real time how much of a disaster) and predicted it with some accuracy. But we’re now at the point where it’s really undeniable that these glaciers are going fast.

The Rhonegletscher in the timelapse above is a really iconic glacier in the Alps, I have my own favourites, mostly places I’ve worked, like Norway, Iceland and Greenland, which are all to a greater or lesser extent retreating fast now. The glaciers that people consider iconic or at least well-known tend to be accessible and depend very much where you are and they will be the glaciers we mourn over in the next decades. In the French Alps, it’s probably the Mer de Glace, in Switzerland perhaps Rhone glacier or Plaine Morte (both have monitoring programmes), in Canada perhaps the Malaspina or Athabasca glaciers. There are still (just) glaciers on Kilimanjaro and Mount Kenya, the Ruwenzoris are basically gone, as are the Papuan glaciers.

One of the longest records anywhere in the world for glacier length change is Nigårdsbreen in Norway. This plot was put together by NWE: The Norwegian Water directorate who monitor a number of glaciers

Though they show in the study that ice loss is basically linear with temperature, at some point the glaciers become so small that the remianing melt is highly non-linear. And these won’t grow back under any sensible “overshoot” scenario (never mind that we don’t really have technology to remove carbon from the atmosphere at scale). Once they’re gone, they’re basically gone forever on human timescales Finally, I’d like to add a bit of anlaysis by Ben Marzeion and co-authors , it’s possible to basically put a number on the amount of melted glacier ice each kg of CO₂ leads to.

We find that under present-day climate conditions, every emitted kg of CO2 will eventually be responsible for a glacier mass loss of 15.8 (5.9–20.5) kg. Again, since the global glacier mass is decreasing with increasing temperatures, this number is greater for lower temperatures and smaller for higher temperatures.

Marzeion et al., 2018

It’s past time to stop burning fossil fuels.