Climate adaptation will also most likely (going by previous history), be unevenly spread and probably not focussed on those feeling the biggest impacts, but those most able to pay for it.
This is something I’ve been pondering for a while, and I’m not really sure how to grasp it, but perhaps more and better work with the social scientists is necessary?
I was struck yesterday by this related snippet from the IPCC AR6 WGII report, posted by David Ho (and I gather courtesy Eric Rostrom), pointing out that heatwave impacts will be unevenly distributed between high and low income people.
At the same time, I also read an interesting piece in the Danish newspaper this weekend suggesting that heatwave exposure is a new marker of class, even in Europe. With the working class toiling in fields, roads, kitchens and on building sites, while the higher educated white collar professionals both able to take advantage of air conditioning and to afford time off in cooler places. This is not a new argument. But it is yet another argument for unions and robust government regulation to try to limit heatwave morbidity and mortality where this is possible. Trades unions may not be able to solve all problems, but they can definitely help when it comes to working conditions!
On a similar note, but outside Europe, the Economist has an unexpectedly excellent piece on how meteorology can help to mitigate weather and climate driven disasters . The whole piece is worth a read as it very much aligns with developments I can see at DMI. They point out for example the great possibilities offered by AI methods in weather forecasting, and how they can be applied to climate models (something I hope to start working on this year), as well as the dangers that AI could be used to undermine the robust national infrastructure that machine learning models are in fact built on.
However, the most important point is that so often, the main challenge is getting extreme weather warnings and other important information out to people affected.
“24 hours’ notice of a destructive weather event could cut damage by 30%, and that a $800m investment in early-warning systems for developing countries could prevent annual losses of $3bn-16bn.”
No breakthroughs are required to put this right, just some modest investment, detailed planning, focused discussion and enough political determination to overcome the inevitable institutional barriers. It is not an effort in the Promethean tradition of MANIAC’s [sic – an early pioneering weather supercomputer] begetters; it will neither set the world on fire nor model the ways in which it is already smouldering. But it should save thousands of lives and millions of livelihoods.
And this is probably generally true of the way we should think about climate change adaptation in the near and short term: how to leverage the best possible information to help make decisions and nudge behaviour to remove people from harm.
I was talking to some friends today about climate change – in the light of the latest #AMOC paper, suggesting a tipping point. I’m far from an expert on AMOC so if you’re here for that I suggest this comprehensive piece on real climate from Stefan Rahmstorf.
It’s been hot, in short and even if July has been cooler and rainy in Denmark, May and June were hot and record dry..
And it’s fair to say that, as when I’m asked why, or similar questions by journalists, there is an almost overwhelming temptation to say “we told you so”. I think that’s what Antonio Guttieres is getting at here too.
There’s of global boiling is upon us. Apparently. It certainly felt like it on my summer holiday this year…
However, that’s not what I was mostly musing on. Given the apocalyptic heatwaves, strange patterns of warming in the ocean and the Antarctic sea ice loss, it feels a little like end of days.
However, in the long-term (and I do mean really long-term – on the century to millennia scale), we’re facing something more existential. We’re going to lose a lot of Danish land to sea level rise. Exactly how much will largely be determined over the next 20 to 50 years as there’s a pretty clear relationship between greenhouse gases and melting ice.
But we do have time to prepare for it- and most importantly to have some grown up conversations about our priorities as a society. This is going to require a good bit more social and behavioural science. In the medium term, we will need to prepare for ever more storm surges, but adaptation to coastal flooding also falls into the engineering category.
Of course, these local to regional risks still need dealing with and that is largely why my employer has created the awesome Danish climate atlas – to give accurate but also useful climate information to those who need to plan for the future. I suspect an ever greater part of my job will be focused on producing usable projections and climate service information. This is certainly also something we will focus on in the PRECISE project. Being able to make useful sea level rise projections is about more than identifying if an ice sheet is stable* or not, it’s also about how quickly, how likely and how much it is likely to retreat. As we have also focused on at a regional level in the PROTECT project
So that’s ice sheets and sea level. The tl;dr is, we know they’re melting, we still don’t know by how much and how fast they’ll ultimately melt but we still have time to deal with it, at least in wealthy well educated societies like Denmark,.
There is a whole nother discussion to be had about the global south and less equal societies which I don’t feel confident enough to discuss here.
And then there is some evidence that multiple heatwaves could occur concurrently, threatening food production in compound events across several key regions. Perhaps working out how to make the global food chain less vulnerable to disruption at key points should be more of a focus than it is?
And that’s after the latest banditry from Russia, destroying perfectly good foodstocks and the means to distribute them, has given us a clear wake-up call on the interdependence of human society.
(Anders Puck Nielsen a military commentator has an interesting take on that from a strategic point of view here: https://youtu.be/fvPcPZP-6os which is very interesting for Ukraine watchers)
If I were a wise and concerned government I think I’d be thinking about how exactly we’re going to be feeding our population over the next 5-20 years. Where will be able to produce like Spain and Italy today? Or will diets have to change? How do we persuade people to eat more healthily and ensure that food is equitably spread through society?
This is of course also a part of the job of the other working groups, 2 and 3 of the IPCC – and it’s possibly not just an accident or indeed good lobbying that the new IPCC chair, Jim Skea, is a former WG3 coordinator. Perhaps the IPCC also sees that we have now moved into a new world.
So, these are just some of the things I’m thinking about as I prepare to go back to the office after the summer break next week.
As I observed on Mastodon after the IUGG meeting, and online with this excellent heatmap article. Climate science is entering a new phase. It’s the end of the beginning and it’s time to prepare.
*On the subject of ice sheet stability, Jeremy Bassis has an excellent thread on what this does and does not mean over on Mastodon. Worth checking out
The project is led by Professor Christine Hvidberg at the Niels Bohr Institute and there is a really nice interview with her on their website about our plans that’s worth a read. I’m co-PI and lead on surface mass balance processes and coupled climate models within the project so I thought it might be worth giving a quick overview of what we hope to achieve.
TL;DR? We will be improving estimates of and assessing the uncertainties in sea level rise projections from the two big ice sheets in Greenland and Antarctica.
Every science proposal has a graphic like this somewhere showing how the whole project hangs together. This is ours…
Slightly longer version: we’re using new approaches from materials science to incorporate “new” physics in ice sheet models. We’re also integrating in-situ observations and satellite data into our model frameworks and using these to train machine-learning tools. My work package will emulate our physics based numerical climate models to expand the ensemble and generate a statistical approach for assessing ice sheet stability as well as investigating important feedbacks between different elements of the earth system. Finally, we (or rather my colleague Christian Rodehacke and his postdoc) will run our coupled climate – ice sheet model (EC-EARTH-PISM), including these advances, to generate new sea level rise projections.
The outputs from all these experiments will be communicated and developed in collaboration with the Danish Klima Atlas (Climate Atlas) to ensure we are focused on the right kind of data and time periods for use by stakeholders and local populations when it comes to adaptation planning.
Current projections of change in average sea level around Denmark from the klima atlas
So why this project?
One of the most iconic images to come out of the last IPCC 6th asessment report (at least in my little corner of the climate science universe) is this one on sea level rise projections out to 2100.
Much of climate science has, at least to some extent been “solved”. At least in the sense that we understand the mechanisms and processes quite well and the remaining uncertainty is to some extent tinkering around the edges, often bound up with uncertainty on scenario, or related to impacts – there’s still quite large uncertainty on what will happen to the Amazon rainforest at different levels of emissions for example. However, sea level rise is really an exception to this. It’s very difficult to be sure that some very unpleasant surprises are really implausible.
The IPCC for example, concluded that sea level rise of 15 metres or more by 2300 can’t be ruled out, even if it seems rather unlikely. And this poses a pretty large problem to planners, politicians, stakeholders and providers of coastal services. Working out how far and how fast we expect the sea to rise is really our challenge.
But there is also a risk of abrupt and extreme sea level rise that could come round the corner to surprise us. However, it’s hard to know how likely this is or even how to evaluate that risk.
Where PRECISE differs is that we have the flexibility within this project to develop new and innovative techniques that we’re not quite sure will work: especially the development of machine learning tools.
The EU science budget is a brilliant thing, but risky research is difficult to get through, the Move Nordisk challenge centres allow us to try really new and, yes, risky techniques. Though climate is a new topic for them, so we’re very much test bunnies in this new phase of funding science for them.
So what are we going to be doing practically?
Measuring snow pack properties in Greenland, with the help of the Lego scientists..
Our partners at NBI include Joachim Mathiesen, Helle Astrid Kjær, Aslak Grinsted and Nicholas Rathmann. They will be focusing on assembling field data from both ice sheets, and developing new physical solutions for ice sheet models based on solutions from materials science. They will be looking at phase field approaches for ice flow, at new solutions for calving and ice fracture and integrating these into ice dynamical models. NBI will also be doing fieldwork to collect new surface mass budget (SMB) data from the ice sheets.
A new ice fracture appears, how to understand and model these is a key part of the NBI contribution in PRECISE project.
The SMB part of the work is part that I’m especially involved in. Not just in modelling SMB with our climate and weather models as we do on the polar portal but also in getting a much better understanding on the uncertainty in these models associated with precipitation (which is much higher than that associated with e.g. temperature, especially when it is snowfall). So new observations with a high time resolution will be key for improving our current snowpack models.
A shallow ice core, in this case sea ice, but part of the fieldwork will focus on taking more of these samples and doing isotope analysis on situ to get high quality data on snowfall accumulation
We will also be working on bringing regional climate emulators into use over both ice sheets to see how varying starting conditions will vary the outcomes. We know that on a chaotic system like weather starting conditions are key and emulators allow us to do many many more experiments than with our physics based numerical codes alone. It’s pretty cutting edge stuff right now but I know several groups are working on this – including this fantastic paper that recently came out of the Delft/Leuven group, which really shows what is possible
Our other collaborator, Hilmar Gudmundsson at University Northumbria Newcastle will be working on implementing these processes in ice sheet models and examining how plausible instability in ice sheet simulations is using ensembles of multiple model simulations. They will also be using and developing their ice shelf emulator to look at basal melting and investigating the potential instabilities in Antarctic ice shelves that could lead to abrupt sea level rise.
The project will receive 42 million Danish kroner in total (about 5 million euros) of which 8 million dkk will fund work at DMI, work to be carried out by 2 postdocs and a PhD student (so if this sounds like something you’d be interested in working on do get in touch) over the next 6 years from September. In fact most of the funding we have received will go directly to early career scientists, there is nothing in the budget for us seniors! Naturally this has some disadvantages, but given the rapidly aging population within Europe and European science, I see it as a positive and we have lots of cool summer schools, bootcamps and other networking activities planned that will hopefully reach out beyond PRECISE to the rest of the ice sheet – climate community.
Yesterday, I attended a mini conference on power to X and the potential to generate green synthetic fuels in Greenland.
Power to X became a big thing in Denmark a few years ago and the government is keen to promote it. Danish company Topsoe are currently building a green fuel facility in Herning and they have a nice explainer on their website of the concept.
In Greenland the fuels could be anything from hydrogen to methanol (though I learnt methanol is least likely as it requires a CO2 source that Greenland doesn’t have, ammonia seems the most plausible initially).
It was an interesting meeting, lots of different companies, institutions and the Greenlandic MP Aaja Chemnitz as well as academics were in the room. The emphasis was very much on the social and economic aspects of power to X, but as the title implied: Greenland has the potential to be the “world’s largest energy island.” From a local point of view, Greenland has very high per capita emissions and is heavily dependent on energy imports for transport, though a majority of electricity, at least in the south west, is already hydropower.
Many other smaller and more remote communities however are dependent on diesel generators for heating and power as well as for shipping, fishing and flying between communities.* Transitioning away from these fuels will be challenging but the potential for much larger developments is clear.
Head of development at NunaGreen (the recently rebranded and reoriented NunaOil), Rasmus Wendt, emphasised just how cheap and in theory at least, abundant, Greenland hydropower is. Probably some of the cheapest electricity in the world is generated by Greenlandic dams already operating or planned. And indeed the potential is massive. As the ice sheet melts, enormous amounts of water are produced more or less endlessly in Greenland. It will take at least a thousand years to melt the whole ice sheet, even under a high emissions scenario. We’re not going to run out of water soon.
Figure 2 from Aschwanden et al., 2019. Observed 2008 state and simulations of the Greenland Ice Sheet at year 3000. (A) Observed 2008 ice extent (53). (B to D) Likelihood (percentiles) of ice cover as percentage of the ensemble simulations with nonzero ice thickness. Likelihoods less than the 16th percentile are masked. (E) Multiyear composite of observed surface speeds (61). (F to H) Surface speeds from the control simulation. Basin names shown in (A) in clockwise order are southwest (SW), central-west (CW), northwest (NW), north (NO), northeast (NE), and southeast (SE). RCP 2.6 (B and F), RCP 4.5 (C and G), and RCP 8.5 (D and H). Topography in meters above sea level (m a.s.l.) [(A) to (H)].
Wind energy too is extremely underdeveloped but potentially huge in Greenland. The problem is of course, all that potential energy is a long way from the end users as this screenshot from the global wind atlas, shared by energy scenario planner Brian Vad Mathiessen shows well.
Screenshot from the global wind atlas showing wind energy potential in Greenland and the north Atlantic margin of Europe
By sheer coincidence, this morning I stumbled over this article in the Dutch newspaper NRC on mastodon about the large green hydrogen facility currently under construction by Shell in Rotterdam.
It’s a really interesting read – (if you don’t speak Dutch try DeepL translation) and I was struck by many of the same issues being raised there as in the Greenland meeting: lack of trained staff, uncertain commercial environment, cost and competitiveness with other energy sources. Unlike in Greenland, energy in the Netherlands for producing synthetic fuels is scarce, but the market for using the energy is huge and nearby, and given the EU’s ambitions to produce and, crucially, import large amounts of hydrogen fuel by 2030, it seems like many of the important stars are aligning. Importing ammonia to Rotterdam for cracking back into hydrogen seems like it could actually be a viable future for Greenlandic generated fuels in Greenland he medium to long term.
We at DMI are shortly starting a project within the National Centre for Climate Research framework looking at exactly the potential to generate renewable energy from a climate and weather angle. But what I took away from yesterday’s meeting is that while the physical potential in Greenland really is HUGE, the regulatory environment – and probably the local population – is supportive, the economic certainty is not quite there yet.
It felt a bit like being in a bunch of young seabirds clustered on the edge of the cliff, none quite daring to take the flight, in spite of the undoubted rewards. And indeed, this seems the situation in the Netherlands too. I was especially struck by this quote in the NRC piece:
“Another problem is that many parties are just waiting for each other to take the first step so that they themselves dare to go. Producers, for instance, invest only sparingly because they are not sure whether there will soon be customers, and customers in turn hesitate because they are not sure whether the producers will deliver. The classic chicken-and-egg story.” (Translated with DeepL)
Chris Hensen, NRC, 17thnMay 2023 “De Europese waterstofambities zijn groot, maar bedrijven zijn nog altijd afwachtend”
Perhaps the diving in of Shell, a company that can afford to risk investing a billion Euros in a new facility in Rotterdam, is what the development of Power to X needs?
BP, Air liquide and Uniper already have plans to build follow on plants in Rotterdam. Once one of the birds have taken flight, others will surely follow.
Thanks to Aalborg University,and especially my Danish Arctic Research Forum colleague Carina Ren for an interesting and inspiring meeting.
*(As an aside, I was reflecting while on fieldwork just how difficult removing fossil fuels from scientific work in Greenland will be. We rely on petrol generators to power equipment and oil stoves to warm tents. What if we could develop an easy to operate “tabletop” (or even just room sized) electrolysis system to generate clean fuels from e.g. wind energy, that we could burn instead of paraffin and/petrol? I’d invest in that and it would be a quick win for Greenland science.)
Inside of the tent during fieldwork, note the primus stove, running on petrol, for melting ice for water and food and the paraffin powered oven to keep the inside warm and dry while camping.
Back in Denmark after 2 weeks in Greenland. Always a bit strange to come back, not just that transition from Arctic cold to European Spring but the sheer abundance of the fertile mid-latitudes, colours, plants, trees, the sheer number of people.
Not to mention that expedition frame of mind, where you are really focused on accomplishing a given set of often quite complex tasks (almost) without distraction. It is the ultimate deep work task, and naturally readjusting to family life, not to mention the tsunami of work tasks left on hold is… difficult.
The town was formerly a summer hunting spot, but after Thule was decided on, the community was moved to Qaanaaq year round. It has an association with the famous Danish explorer Knud Rasmussen, whose old house is a museum (allegedly. I’ve never actually had time to visit it..)
This year we again visited the glaciers at the head of the Inglefield Fjord – expanding a new research programme we piloted last year. We also did a lot of work on the sea ice – not just Steffen Olsen‘s ocean programme, but a new NCKF research programme looking at biological productivity and carbon cycling in the fjord, led by Anna Pedersen, a DMI PhD student also at the University of Southern Denmark. I and another colleagues also did a lot of work on snow processes that is something of a pilot programme for a processes project we’d like to establish next year that will also involve (hopefully) our weather forecasting colleagues and perhaps also the GEUS PROMICE programme.
All of this work involved 6 days of travelling over and camping on the sea ice, plus an additional day trip. We were lucky with the weather, although it was *extremely* cold, around -25 to -28C most days, and dipping well below -30C at night (though being after the equinox it was never truly pitch dark). However, in general there was little wind, no fresh snow (which can really slow the dogs down as they struggle to pull through deep soft snow) and the sun shone every day. This meant we basically managed to achieve the full planned programme – including our extra-optimistic goals – which almost never happens in fieldwork.
I intend to write a whole series of posts based on what we have been doing scientifically and technically as well as some general observations. There have been various hints already in my preferred social network. The whole trip was super inspiring, it’s always valuable to get out and observe the real world when you’re trying to model it, understand it and make projections of sea level rise.
I also promised to make another Lego scientists series and took quite a few photos in between times to do so. However, the research programme was packed, so I had no time at all to make the comic during fieldwork, that will have to wait a few weeks.
Expect my pixelfed account to host gratuitous numbers of dog pictures. And ice pictures. And unexpectedly clear blue skies. For now it’s time to unpack, get the washing machine going and spend some time with my family.
As ever, thanks to my amazing colleagues Steffen Malskær Olsen, Andrea Gierisch and Anna Pedersen for an incredible trip and to DMI station manager in Qaanaaq Aksel Ascanius without whom most of this work would be impossible.
Special thanks to our friends in Qaanaaq, the local hunters, whose unfailing energies and knowledge are absolutely essential to these scientific projects. We literally could not do this without them and of course their dogs.
I must also credit DMI and the Danish Government for funding via the National Center for Klima Forskning and thanks also to Horizon Europe projects PROTECT on sea level rise and PolarRES for additional inspiration and funding and to my colleagues at the Horizon Europe/NERC project OCEAN:ICE for indulging my two weeks away. All three projects will benefit from the insights gained in this fieldwork.
It’s a really thorough introduction to the climate system and all the natural sources of climate variability and cycles of change, including links to sources. Well worth taking your time over with a morning cup of tea and probably I’ll assign it as an introduction text for BSc students (and management) on the big picture of climate change.
I also love it for the introduction where multiple eminent and respected scientists are asked what they’d buy with all the dollars they’d have if they were given one dollar every time someone asked them about “natural climate cycles”. As you might expect, the answers range from heat pumps and solar panels to new bicycles and a time machine.
Not sure what I’d use it to pay for, possibly a new postdoc position to work on snow and ice processes?
*as an aside: I haven’t read Ars Technica in ages. And it’s funny because I remember that when I first started on twitter way back in 2010 there were *a lot* of good articles shared from there on the bird site. Somehow they either were not shared or got suppressed and I stopped seeing them. I’m not sure if that was due to the algorithm or different people I was following. One of the nice things about mastodon is that without an algorithm (and crucially, by following *a lot* of people!) there is a chance to see a much greater diversity of different media. It feels a bit like seeing a different internet, outside the standard walled garden.
I’ve been on holiday this last week and I’m combining the trip to the UK with a visit to colleagues and collaborators at the University of Leeds. I’ve also been nabbed while I’m in Leeds to give a wider interest talk at the Royal Meteorological Society Yorkshire branch in Leeds.
I’ll be discussing ice sheets, their contribution to sea level rise and how the future is looking. There may also be some nice photos from our fieldwork in Northern Greenland for those who like dogs, icebergs and snow…
If you’re in Leeds and fancy joining you’re most welcome to register and attend at this link.
In general, I’m trying to reduce my travel this year, last year, with all the rolled over meetings from the COVID times was disruptively busy with work travel, it makes it challenging to actually get the work done. So I think combining work and holidays and rolling up meetings into a block is the way forward.
Although I very much appreciate the opportunity to present online at various meetings, I’m less convinced about hybrid meetings where the purpose is mostly scientific discussions, that is something that works much better either all online or all in person in my opinion, but I think they work well when the aim is to present new and ongoing work (like EGU).
For those who are interested but can’t attend I will see if the talk tomorrow will be recorded and can be uploaded somewhere. Here’s the abstract:
Frozen Threats: Understanding the Role of Ice Sheets in Sea Level Rise
In this talk, we will delve into the world’s ice sheets and explore their importance in the climate system. Ice sheets are the largest stores of freshwater on the planet, their size and location means they influence our climate but their interactions with the atmosphere and ocean are complex. As the world warms, they will inevitable have an impact on sea level. Adapting to sea level rise will be one of our civilisations biggest and longest challenges, so understanding ice sheets is now of critical importance. They are also beautiful and fascinating environments in their own right. In this talk I will discuss some of the scientific challenges, but also show how far we have come in understanding ice sheets and glaciers.
The Inughuit cliffs near Qaanaaq in Northern Greenland rising up above the sea ice. In the far distance a dog-sled is a small black speck.
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.
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.
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.”
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.
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.
#Glacier ice melt in 2022 was impressive! See the incredible speed of ice loss at the snout of Rhonegletscher (@VAW_glaciology time lapse by A. Cremona)…
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.
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.
I have been meaning to write about my return to field science (after 10 years mostly working on climate models) for the last 2 years, but prompted by this beautifully written piece in the Danish Newspaper information, I decided Christmas Day was the day (it for sure beats the washing up)…
“For at forstå, hvad der er ved at ske ved kloden, rejste vi mod isens ende” “To understand what is happening to the earth, we travelled to the end of the ice”
Martin Bahn og Anders Rye Skjoldjensen (foto) in Information 23rd December 2022
To make one thing very clear straight away, and as the newspaper article also makes very clear, my colleague Steffen Malskær Olsen has established and maintained a very long-running programme of observations in the fjord near Qaanaaq. This town in northern Greenland on the edge of a large fjord, and close to the North Water polynya has a uniquely interesting location to study and understand Arctic processes. The DMI facility there is long established and part of the INTERACT network of Arctic field stations. The 15-year record collected by Steffen is more or less unbroken and uniquely valuable. None of the science I’m planning to do or to work on would be possible without his dedication, hard work, insight and bridge building within the community in Qaanaaq. He and my other DMI colleagues involved in this programme are brilliant scientists and great field companions and I feel privileged to be able to work with them in this incredible place.
In the field: Steffen and team retrieving an oceanographic mooring with instruments on it after a winter out in the fjord in 2021.
Secondly, as the article also makes clear, scientists are not individualistic heroes who beat the odds, it’s a team sport. And it’s especially true in Greenland where the true heroes of this story are probably not scientists but the local hunters and fishers who guide and transport us and whose knowledge and experience is unmatched. I include also on this category our DMI colleague Aksel Ascanius who lives and works in Qaanaaq has been an essential part of the programme since the earliest days, as well as keeping other long-term observations in the network running in this part of the world.
Collaboration with the people who live in the Arctic has been essential for success in Arctic science since since the days of Franklin and Rae (for British readers) or Suersaq, aka Hans Hendrik, (after whom Hans Island is named) for Danes..
Anyway, back to the science of the present-day. DMI has progressively added more and more elements to the field laboratory in Qaanaaq in addition to the longer running observations. A non-exhaustive list would include an infrasound monitoring station that is part of the CTBTO, weather observations (of course), surface emissivity measurements by drone, fjord salinity, temperature and photosynthetically available radiation measurements plus snow and sea ice measurements as well as work with satellites and biology. One glaring omission, up to this year at least, was the glaciology of the region. How does the ice sheet affect the regional climate, how does the ocean affect the glaciers that calve into the fjord? Can we learn about some important but poorly understood processes like calving and melange dynamics using this area as a test bed? What about surface mass budget and snowfall and snow melt?
A lead in the sea ice – these fractures in the ice have sea water (the black) welling up between two thick plates of sea ice. The conditions were perfect for frost flowers to grow on the surface. Sea ice turns out to be a lot more interesting – and complex- than I’d ever imagined…
Now, as a glaciologist, I’ve mostly worked with the interface between atmosphere and ice sheet (at least the last 14 years or so, but I am also still (after my PhD topic on ice fracture and crevasses) interested in calving glaciers and the processes that control how fast icebergs form. And the fjord, Inglefield Bredning has *a lot* of calving glaciers in it. It is a natural laboratory for glaciology and for developing numerical models. Calving is actually a surprisingly difficult thing to model with computer models of glaciers.
Or perhaps it’s not that surprising?
Observations are difficult to get (to put it mildly). There are a number of (possibly wild) theories of “calving laws” that remain poorly constrained by observations as a result. Common parameterizations of ice flow makes it hard to deal with fast flowing glaciers where calving is common. Dealing with grounding lines, where glaciers meet the sea and start to come close to flotation can give notorious numerical errors and retreat requires the remaking of ocean grids in fully coupled climate models.
Satellite image from ESA’s Sentinel-2 satellite showing glaciers calving icebergs into the head of the Ingle field Bredning fjord. The black is open water, icebergs show up as blueish dots, the land is carpeted in snow. Low winter sun (in late September 2022) casts deep shadows.
These are not easy or computationally cheap problems to solve. And where there are at least thousands (maybe even tens of thousands?) of scientists working on atmospheric weather and climate modelling, the community working on ice sheet dynamic models is probably only in the low hundreds.
And of course, we really lack long time series of measurements – essential in a system that changes only s l o w l y, but likely irreversibly and which we are, only now as the system is changing rapidly, starting to understand.
This of course is why the fjord observation record of Steffen is so valuable – these are reliable, repeated measurements of ocean properties that are known to affect the outlet glaciers that meet them. It is indeed a natural laboratory.
What we are now also working on is a field lab to study these calving processes in-situ. I have already found the return to the field scientifically valuable. There is really no replacement for going to observe the earth system you want to understand. (My PhD supervisor used to call it “nurturing your inner glacier”). Observations taken in spring/summer 2022 have already changed how I think about some processes and hopefully the follow-up we have planned in 2023 will confirm our new theoretical framework.
Heading home from the deployment of instruments out near calving glaciers at the head of the fjord.
I am fortunate indeed in that at the same research department, we also have colleagues collecting and analyzing satellite data and developing the numerical models we want to use to understand how ice sheets fit into the earth system. All three of these elements – field, satellite and numerical model- are essential.
In this project we are using the satellite observations to extend the time series of field data and we can use both sets of observations together to develop and test a numerical model of this fjord and the glaciers that calve into it. The numerical model we can then extend to other glaciers in Greenland. Hopefully, we can also use this work to understand how Antarctic glaciers might also respond to a warming ocean. Ultimately, the aim of all this work is to understand the contribution of these glaciers to sea level rise both now and in the future.
This is not a frivolous question. In fact, if large (more than a couple of metres).of sea level rise is expected, it is a question that is basically existential for Denmark.
I will add more on the specifics and science in coming months, this is already long enough. However, I’d like to mention a couple of other points:
Firstly, DMI is by no means alone operating up here. Many of the key articles, particularly on glaciology in this region, have been written by the Japanese group at Hokkaido University and their collaborators at the Meteorological Research Institute, the national institute for polar research and others. We at DMI are also working directly with the Greenland institute of natural resources, Asiaq, GEUS, KU, DTU, AU, SDU, ESA, Eumetsat and many others in this research programme.
Finally, this work is currently being carried out under the auspices of the Danish National Centre for Climate Research (NCKF), funded by the Danish Government though with contributions also from other research projects mostly funded by the EU’s Horizon 2020 and Horizon Europe frameworks as well as ESA’s climate change initiative for the Greenland ice sheet.
