Sign in

Tanja Schlemm (she/her)

@tschlemm.bsky.social
294 followers 245 following 35 posts

I do numerical modelling of ice sheets, iceberg calving and sea ice melange at PIK, exploring their role in climate change and our planet’s future.

PostsRepliesMedia
Reposted by Tanja Schlemm (she/her)
Zeke Hausfather @zekehausfather.com · 06/10/2026
This year's El Niño continues its climb into uncharted waters; Niño3.4 region anomalies are now at a 3.4C above normal (how fitting!), higher than any prior El Niño event on record. September monthly Niño3.4 anomalies also set a record at 2.9C (beating 2015 and 1877's 2.75C).
821194
Reposted by Tanja Schlemm (she/her)
Jeremy Bassis @bassisjeremy.bsky.social · 06/10/2026
Celebrate IceCube and, as a polar scientist, I believe IceCube is a phenomenal scientific achievement. But (trigger warning) I also want everyone to read and sit with the USAP report on sexual assault and harassment in the US Antarctic Program because I can't entirely separate those two things.
nsf-gov-resources.nsf.gov
183
Reposted by Tanja Schlemm (she/her)
Prof Lisa Schipper 🌍🍉💪 @lisaschipper.bsky.social · 06/10/2026
I’m not sure if it’s clear to the public that most policymakers and scientists have left 1,5C behind and are planning for warming that is closer to 3C. That is a major difference.
67837
Reposted by Tanja Schlemm (she/her)
Bob Berwyn @bberwyn.bsky.social · 05/10/2026
New data and a report released Friday by @copernicusecmwf.bsky.social show the intensity and geographical scope of last summer's deadly and destructive fossil-fueled extremes.
insideclimatenews.org
Europe’s Extreme Summer Triggered Cascading Climate Shocks - Inside Climate News
A summer of record heat, severe drought and compounding impacts tested Europe's infrastructure and resilience.
02114
Reposted by Tanja Schlemm (she/her)
Aaron Becker @aaronjbecker.bsky.social · 03/10/2026
Every river in North America, every day for two years. The combined flow to the sea sinks as low as 53,000 m³/s in winter and swells past 290,000 by late June, more than quadrupling each spring. Data: GloFAS, @copernicusecmwf.bsky.social #rivers #dataviz #hydrology
223496
Reposted by Tanja Schlemm (she/her)
Zack Labe @zacklabe.com · 05/10/2026
#Antarctic sea ice extent has now dropped to the lowest on record for this time year... See more at zacklabe.com/antarctic-se...
Line graph time series of daily Antarctic sea ice extent for each year from 1979 through 2026. This year is currently the lowest on record for the date. A seasonal cycle is also visible on this graphic, but no long-term trend is visible.
5242103
Reposted by Tanja Schlemm (she/her)
Elizabeth Anne, PhD @lacksauthority.bsky.social · 05/10/2026
never the wrong time for this classic
Screenshot of a tweet by @RobbtKraft reading “scientist: "does everyone here know what Watson and Crick discovered?" 
me from back of room: "Rosalind Franklin's notes"”
56120153571
Reposted by Tanja Schlemm (she/her)
Anthony B, @swearyanthony.bsky.social · 04/10/2026
Once again - the problem isn't "ooo AI models are too scary and powerful". It's that the developers of these products are irresponsible dolts, who have absolutely no intention of changing how they behave. Stop making excuses, use existing laws and make them responsible for their own actions.
924398
Reposted by Tanja Schlemm (she/her)
Rob Larter @polarrobs.bsky.social · 04/10/2026
🧵 It's early spring in Antarctica, and weather maps show a continuous stream of warm air is presently running from north of 50° S into West Antarctica's Amundsen Sea Embayment.
1135
Reposted by Tanja Schlemm (she/her)
World Meteorological Organization @wmo-global.bsky.social · 04/10/2026
Earth observation satellites orbit the planet day and night, all year round. They provide critical insights into Earth’s weather, water and climate — monitoring changes and helping us prepare for what’s ahead. View the world from above this #WorldSpaceWeek 🛰️
02713
Reposted by Tanja Schlemm (she/her)
David Ho @davidho.bsky.social · 24/11/2023
IPCC scenarios are projections, not predictions. "The future has not been written. There is no fate but what we make for ourselves." We get to decide what the world will look like in 2100. gmd.copernicus.org/articles/13/...
16366144
Reposted by Tanja Schlemm (she/her)
David Roberts @volts.wtf · 04/10/2026
"Absent policy steering, AI’s modeled effects increase the carbon intensity of the global economy and reinforce fossil fuel incumbency—outcomes that current analytical and governance frameworks do not fully capture."
nature.com
AI-driven productivity gains enable more CO₂ emissions than they avoid in a global energy–economy model - npj Climate Action
npj Climate Action - AI-driven productivity gains enable more CO₂ emissions than they avoid in a global energy–economy model
414464
Reposted by Tanja Schlemm (she/her)
Zack Labe @zacklabe.com · 02/10/2026
This is pretty wild... the average global sea surface temperature (outside of the polar regions) is still above 70°F (21.1°C) through the end of September. This is significantly above the prior record. We'll cover this in our October climate briefing: climatecentral-org.zoom.us/webinar/regi... 🌊
Line graph time series of daily global mean sea surface temperatures from 1982 to 2026. This year is currently at record high for this time of year. Data is from NOAA OISSTv2.1, and the graphic is created by Climate Central at https://www.climatecentral.org/climate-briefings.
5269118
Reposted by Tanja Schlemm (she/her)
Dr. Aaron Thierry @thierryaaron.bsky.social · 01/10/2026
“What we are seeing now is a complete explosion of these melt rates, leading to the disintegration of glaciers. They’re really just falling apart.” #Switzerland 🇨🇭 #ClimateEmergency
theguardian.com
‘Explosion of melt rates’: 20% of Swiss glaciers lost in five years
Alpine regions in Europe experiencing extreme glacier collapse due to heat-trapping effects of fossil fuel pollution
18464
Reposted by Tanja Schlemm (she/her)
Australian Centre for Excellence in Antarctic Science (ACEAS) @antarcticsciaus.bsky.social · 30/09/2026
⛏️ OUT TODAY: new research led by ACEAS CI Prof Matt King @deformedearth.bsky.social and co-authors from 14 countries calls for an urgent, globally coordinated campaign to the Wilkes Subglacial Basin – arguably the last great unexplored frontier of #Antarctica ⬇️
nature.com
Dynamic instability of the Wilkes Subglacial Basin Ice Sheet, East Antarctica - Nature Reviews Earth & Environment
The Wilkes Subglacial Basin is a marine-based sector of the East Antarctic Ice Sheet that is vulnerable to ocean-forced melting and climate warming. This Review assesses changes in ice-sheet extent in...
186
Reposted by Tanja Schlemm (she/her)
Mike Sowden @mikeachim.bsky.social · 27/09/2026
UPDATE: there's a digital reconstruction of this tsunami shared today on Twitter by the UN Office for Disaster Risk Reduction - and *HOLY HELL*.
310133
Reposted by Tanja Schlemm (she/her)
Climate Central @climatecentral.org · 25/09/2026
🚨Both and Pakistan have experienced sustained dangerous humid heat this month, much of which would not have occurred without human-caused climate change. Today, dangerous humid heat driven by climate change is peaking in the region — with around 700 million people forecast to feel it⬇️
12416
Reposted by Tanja Schlemm (she/her)
Prof Julia Steinberger 🌹🌱🌍 #ClimateAction #Fightfascism @jksteinberger.bsky.social · 25/09/2026
In case it wasn't clear, academia is crumbling under the enormous flood of AI-generated content. The latest victim is the Marie Skłodowska-Curie Actions (MSCA) flagship EU postdoctoral fellowships. The number of submissions has more than doubled in the past 3 years.
411052
Reposted by Tanja Schlemm (she/her)
Dr Steve Westlake @steveclimate.bsky.social · 23/09/2026
Lots of research shows that people *really* want to see leaders stepping up on climate change. We call this "appetite for leadership"
1136
Reposted by Tanja Schlemm (she/her)
UK Centre for Polar Observation and Modelling @cpom-uk.bsky.social · 22/09/2026
Fascinating new research led by Michela Savignano (@cires.colorado.edu) with co-author Prof @alibanwell.bsky.social on the Petermann Ice Shelf estuary has been published in the @egu.eu journal The Cryosphere 👇 tc.copernicus.org/articles/20/...
tc.copernicus.org
Temporal evolution of the Petermann Ice Shelf estuary constrained by satellite remote sensing observations
Abstract. Supraglacial rivers may reduce ice-shelf instability by draining meltwater from the ice-shelf surface, limiting loading-induced stresses from ponded meltwater. However, if a supraglacial riv...
153
Reposted by Tanja Schlemm (she/her)
Prof. Anders Levermann, PhD @alevermann.bsky.social · 23/09/2026
Two recent studies in PNAS show: 1) Fractures (which are not represented in current ice sheet models) can easily double the ice loss of a region 2) The fastest changing outlet in Antarctica, Pine Island Glacier, has lost almost all traction due to fractures ... www.pnas.org/doi/abs/10.1...
pnas.org
Fracture-driven weakening amplifies projected ice loss from West Antarctica | PNAS
Ice shelves buttress the flow of the Antarctic ice sheet, but this stabilizing effect weakens as fractures form, reducing ice viscosity and acceler...
14423
Reposted by Tanja Schlemm (she/her)
World Weather Attribution @wwattribution.bsky.social · 17/09/2026
NEW: Climate change is influencing many of the likely drivers behind the devastating rock and ice collapse on the northern Nepalese border last month. 🧵👇(1/6)
111079
Reposted by Tanja Schlemm (she/her)
Ruth Mottram @ruthmottram.eurosky.social · 17/09/2026
New piece on the blog on the new #IMBIE paper. How healthy are the ice sheets? What is driving their mass change and what do we know now after a half a century of observations by satellites? #iceSheets #SeaLevelRise #ClimateChange #ClimateImpacts #EO #SatelliteData
sternaparadisaea.net
Half a century of ice loss: the new IMBIE dataset
A big new community paper has just landed: the IMBIE paper is a big effort to assess the long term health of the ice sheets. What did we find and what does it mean?
12519
Reposted by Tanja Schlemm (she/her)
Prof Ian Hall @ianhall.bsky.social · 17/09/2026
An important reminder that averages can hide where climate change is becoming most intense. Extreme dry-season maximum temperatures across Amazonia are rising more than twice as fast as annual mean temperature in some areas. www.nature.com/articles/s43...
nature.com
Rapid increase of climate extremes reveals new areas of concern in Amazonia - Communications Earth & Environment
Climate change impacts in the Amazon, particularly heat and drought extremes, are increasing faster than average climate trends, with especially rapid changes in the central-northern region that has s...
35523
Reposted by Tanja Schlemm (she/her)
James Murray @james-bg.bsky.social · 13/09/2026
This is a critical point that’s repeatedly ignored. If you’re under 45 there’s a good chance you’re still working in 2050 when we should be at net zero. If you’re under 25 there’s a good chance you’re alive in 2100 when current trends suggest we’ll be at 3C of warming and all that comes with it.
319877
Reposted by Tanja Schlemm (she/her)
ESA Earth Observation @esaearth.esa.int · 15/09/2026
And… we’re connected! Copernicus Sentinel-3C has just sent back its first signall! 📢
0296
Reposted by Tanja Schlemm (she/her)
Matt King @deformedearth.bsky.social · 15/09/2026
For those interested in the Wilkes Subglacial Basin or Antarctic Ice Sheet comms in general, I made some visualisations that may be useful. All are from code and traceable to the data. First, an overview of the system. Full video and metadata: youtu.be/kzpCeVsNNwU
22810
Reposted by Tanja Schlemm (she/her)
Alex Robel @iceclimate.bsky.social · 10/09/2026
However, this doesn’t necessarily mean the Greenland ice sheet isn’t close to destabilization, just that we need to further sharpen other tools that can determine how close we may be to that point doi.org/10.1038/s415...
doi.org
Overshooting the critical threshold for the Greenland ice sheet - Nature
Simulations using two state-of-the-art ice-sheet models show that abrupt melting of the Greenland ice sheet following overshooting of the global mean temperature critical threshold can be mitigated by...
141
Reposted by Tanja Schlemm (she/her)
Proceedings of the National Academy of Sciences @pnas.org · 12/09/2026
Year-to-year variability in the melting of the surface of the Greenland Ice Sheet may not be a harbinger of ice sheet destabilization, according to a study. Variability in the surface mass balance is an expected response to climate warming. In PNAS: ow.ly/2qq250ZMEvb
Meltwater in Greenland, July 2015.
CREDIT: NASA
063
Reposted by Tanja Schlemm (she/her)
David Ho @davidho.bsky.social · 12/09/2026
I wrote this quickly at a bus stop and didn't realize it would go viral, or else I would have worded it better. But the point is that the media is too credulous about AI killing everyone in 10 years (how?) when climate change is killing people now and will only get worse (we know exactly how).
4156771559
Reposted by Tanja Schlemm (she/her)
David Ho @davidho.bsky.social · 13/09/2026
In addition to what I said, LLM math progress threatens the human mathematical community by prioritizing rapid problem-solving over conceptual understanding, human mentorship, and proper attribution. 👇
17316
Reposted by Tanja Schlemm (she/her)
Matt King @deformedearth.bsky.social · 13/09/2026
Great study from my @utas.edu.au @imas-utas.bsky.social colleagues led by student Kaihong Jiao First comprehensive mapping of all grounded Antarctic icebergs, even the tiny ones (still bigger than a house!) that may prove crucial. Story phys.org/news/2026-09... Paper dx.doi.org/10.5194/essd...
phys.org
First Antarctic-wide map of grounded icebergs reveals 'picket fence effect' holding sea ice in place
For the first time, important features of the Antarctic coastal zone have been mapped at high resolution around the continent by training an artificial intelligence tool to accurately recognize ground...
021
Reposted by Tanja Schlemm (she/her)
Dr. Or M. Bialik |📚|🔬|🌊|⚒️ @obialik.bsky.social · 09/09/2026
Another nasty feedback enhancing climate change. Arctic glaciers hold bakc a bunch of ancient methane stored in the rocks beneath the ice. The more glaciers melt, the more methane they are likely to release. 🧪 Link: www.nature.com/articles/s41467-026-…
Conceptual model of subglacial methane mobilization.
Methane can be introduced to the subglacial drainage system by thermogenic and microbial sources, especially beneath temperate ice zones where the ice-bed interface is thawed and hydraulically conductive. Permafrost beneath cold ice zones, where the ice-bed interface is frozen, substantially reduces hydraulic permeability, and therefore methane sources are limited. Once the glacial river is exposed to the atmosphere, methane begins to outgas, although some methane may be consumed in the river by in-stream methanotrophy. Potential additional sources of methane to the proglacial river include in-stream methanogenesis and inflows of methane-rich groundwater.
21914
Reposted by Tanja Schlemm (she/her)
Ruth Mottram @ruthmottram.eurosky.social · 09/09/2026
Spoiler alert: The melange is not going to save us. But actually our findings are much more complex and interesting than just that. Full article in The Cryosphere here: tc.copernicus.org/articles/20/...
tc.copernicus.org
Mélange, landfast sea ice, ice velocities: What controls seasonal calving rates in North West Greenland?
Abstract. Calving glaciers in Greenland frequently exhibit seasonal cycles of terminus advance and retreat and changes in ice velocity and calving rate associated with changing air temperatures, surfa...
0163
Reposted by Tanja Schlemm (she/her)
Ruth Mottram @ruthmottram.eurosky.social · 09/09/2026
Publication day! Our finalised paper on melange processes at Greenland glacier fronts is out now! I wrote about what we did, what we found and what it means for Greenland ice sheet retreat..
sternaparadisaea.net
A jumble of broken ice, and what it means for Greenland’s calving glaciers.
Ice mélange — sometimes known as sikussaq in Greenlandic — is that chaotic jumble of icebergs, bergy bits and sea water that sits in front of marine-terminating glaciers. It’s been described …
13914
Reposted by Tanja Schlemm (she/her)
Alfred Wegener Institute @awi.de · 08/09/2026
Greetings from the North Pole! Last Friday, the Polarstern reached the North Pole for the ninth time. The crew moored to an ice floe, enabling expedition participants to enjoy a few hours on the ice in beautiful weather, while the scientific work continued on board.
16415
Reposted by Tanja Schlemm (she/her)
Helen Czerski @helenczerski.bsky.social · 08/09/2026
It's really hard to take carbon dioxide out of the atmosphere: removing something so dilute is like removing tiny needles from a gigantic haystack, again & again, at huge energy, financial & environmental cost. Very useful thread here on why we can't just assume CO₂ removal is a magic climate pill:
917657
Reposted by Tanja Schlemm (she/her)
William Colgan @glacierbytes.bsky.social · 08/09/2026
Yes, the AR7 WGI expert review period is still ongoing. 👇 Climate experts, please consider if you can help make the next IPCC assessment report as comprehensive and insightful as possible. 🤓
052
Reposted by Tanja Schlemm (she/her)
Ketan Joshi @ketanjoshi.co · 08/09/2026
Alternative view
Treemap titled "OPERATING gas plants" showing most plants in large dark-green blocks labeled chemicals and oil & refining, with smaller dark-green blocks for iron & steel, other, pulp & paper and industrial park, and a small pink block labeled data center.Treemap titled "PLANNED gas plants" showing sector shares: a dominant pink block labeled "data center" and smaller dark blue blocks for other, chemicals, industrial park, oil & refining, iron & steel, hydrogen production, LNG production and several tiny categories.
1235
Reposted by Tanja Schlemm (she/her)
David Ho @davidho.bsky.social · 08/09/2026
All the plastic humanity has ever produced is ~10 billion tonnes. Humans emitted ~10 billion tonnes of CO₂ into the atmosphere in the first three months of 2026. When we appreciate orders of magnitude, we see how intractable the CO₂ problem becomes once we dump it into the atmosphere.
524484
Reposted by Tanja Schlemm (she/her)
Australian Antarctic Program Partnership @antarctic.bsky.social · 08/09/2026
New research shows #Antarctic krill larvae can travel much farther across the Southern Ocean by hitching a ride with drifting sea ice than with ocean currents alone. ↔️ “Year to year, the same starting population of krill can experience very different transport pathways” — Aditya Sharma
2224
Reposted by Tanja Schlemm (she/her)
Ketan Joshi @ketanjoshi.co · 08/09/2026
Global data centre investment has already surpassed solar PV, and will soon surpass all renewable investment combined sf-asset-manager.s3.amazonaws.com/97637/1139/8...
Data center investment rises sharply from near zero in 2015 to about $800B in 2025; chart also shows renewables and solar climbing steadily while oil and gas investments fluctuate at higher levels (2015–2025, USD billions).
79476
Reposted by Tanja Schlemm (she/her)
Zack Labe @zacklabe.com · 04/09/2026
"An image from NASA Worldview shows how brittle Arctic sea ice is becoming due to global warming, with large patches of open water visible near the North Pole on Aug. 29." via @livescience.com at www.livescience.com/planet-earth...
livescience.com
'A worrying snapshot': Satellite image shows large patches of open water less than 40 miles from the North Pole
An image from NASA Worldview shows how brittle Arctic sea ice is becoming due to global warming, with large patches of open water visible near the North Pole on Aug. 29.
11307159
Reposted by Tanja Schlemm (she/her)
William Colgan @glacierbytes.bsky.social · 04/09/2026
Our @firnmelt.bsky.social team is looking for a PhD Student to use airborne radar to assess changes in the near-surface firn of the Greenland Ice Sheet. The position is based in Copenhagen, at GEUS (@anja-ruti.bsky.social) and affiliated with DTU (@louisesandbergs.bsky.social).
123
Reposted by Tanja Schlemm (she/her)
Eos @eos.org · 05/09/2026
Resources such as sea-level-rise viewers, heat maps, and flood prediction services are crucial tools in a changing climate. But many communities who may benefit from these tools face barriers to accessing them. New research works to bridge the gap. #AGUPubs eos.org/research-spo...
eos.org
Communities Affected by Climate Change Need More Than Data - Eos
Researchers and residents in Puerto Rico collaborated on how NASA Earth Observations data can address environmental justice challenges and strengthen community resilience.
075
Reposted by Tanja Schlemm (she/her)
Bjerknes Center for Climate Research (BCCR) @bjerknes.uib.no · 02/09/2026
NEW PhD Research Fellowships in Climate Dynamics! Two 3-year PhD positions available, with possible 4th year including teaching/career development. One position is financed by the GRADIENT-project, and one position is financed by the University of Bergen. @unibergen.bsky.social 🧪🌊
jobbnorge.no
Two PhD Research Fellowships in Climate Dynamics (307296) | University of Bergen
Job title: Two PhD Research Fellowships in Climate Dynamics (307296), Employer: University of Bergen, Deadline: Thursday, September 24, 2026
077
Reposted by Tanja Schlemm (she/her)
Australian Centre for Excellence in Antarctic Science (ACEAS) @antarcticsciaus.bsky.social · 03/09/2026
🌏 JUST OUT: a major international review paper, involving 80 scientists from 16 countries, has outlined a bold plan to address some of the biggest uncertainties in #Antarctic driven #sea-level rise. Read the paper ▶️ agupubs.onlinelibrary.wiley.com/doi/10.1029/...
Review of Geophysics

Toward an Improved Understanding of the Antarctic Coastal Zone and Its Contribution to Future Global Sea Level.

Kenichi Matsuoka, Geir Moholdt, Jennifer F. Arthur, Julien A. Bodart, Xiangbin Cui, Fausto Ferraccioli, René Forsberg, Vikram Goel, Tom A. Jordan, Felicity S. McCormack, Ruth Mottram, Hamish D. Pritchard, Calvin Shackleton, Kirsty J. Tinto, Fredrik Boberg, Marie G. P. Cavitte, Reinhard Drews, Pierre Dutrieux, Jörg Ebbing, Olaf Eisen, Hannes Eisermann, Alex S. Gardner, Chad A. Greene, Nicholas Holschuh, Stewart S. R. Jamieson, Byeong-Hoon Kim, Naomi Krauzig, Bernd Kulessa, Carlton Leuschen, Jilu Li, Lu Li, Jonas Liebsch, Joseph A. MacGregor, Emma MacKie, Anirudha Mahagaonkar, Joséphine Maton, Mathieu Morlighem, Francisco Navarro, Peter D. Neff, Inès N. Otosaka, Frank Pattyn, Antonia Ruppel, Rebecca J. Sanderson, Hélène Seroussi, Andrew Shepherd, Matthew R. Siegfried, Thomas Slater, Arjen P. Stroeven, Michael Studinger, Thomas Teisberg, Ryan A. Venturelli, Jeremy P. Winberry, Chen Zhao, Lu An, Jonathan L. Bamber, Robin E. Bell, Robert G. Bingham, Johanna Brehmer-Moltmann, Graeme Eagles, Jamin Greenbaum, Jorn Gronset, Won Sang Lee, Emmanuel Le Meur, Lenneke M. Jong, Katrin Lindbäck, Sven Lidström, Mareen Lösing, Masahiro Minowa, Mayuri Pandey, Yogesh Ray, Mirko Scheinert, Dustin M. Schroeder, Thorsten Seehaus, Kaian Shahateet, Daniel Steinhage, Xueyuan Tang, Drew Taylor, Hannah Verboncoeur, Junjun Yang, Duncan A. Young.

Link to paper: https://doi.org/10.1029/2022RG000803
156
Reposted by Tanja Schlemm (she/her)
Konstantin Weber @konstantinweber.bsky.social · 24/08/2026
Temperature overshoot means more than cleaning up a slightly bigger mess a little later. TL;DR: If we ever return to 1.5 °C, it will likely take centuries. The way overshoot scenarios are often sketched fails to highlight that. iopscience.iop.org/article/10.1...
iopscience.iop.org
Anchoring overshoot in reality
Anchoring overshoot in reality, Weber, Konstantin, von Rothkirch, Juanita, Brunner, Cyril, Knutti, Reto
198
Reposted by Tanja Schlemm (she/her)
Erik Loebel @erikloebel.bsky.social · 01/09/2026
Two weeks ago, a 14.5 km² iceberg calved from Nioghalvfjerdsbræ (79°N Glacier). More significant: the ice bridge holding the floating ice tongue is now just ~4 km wide. Its collapse could result in destabilization and be a precursor of disintegration of Greenland's largest floating ice tongue.
131
Reposted by Tanja Schlemm (she/her)
Jeremy Bassis @bassisjeremy.bsky.social · 01/09/2026
Update: The students are terrified of using AI and not using AI. The students want to learn. They know AI is a threat to learning. A couple of really good discussion points emerged. For example, an outright ban on all AI use is not practical because AI snakes itself into so many uses.
195