Tanja Schlemm (she/her)
@tschlemm.bsky.social
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.
Reposted by Tanja Schlemm (she/her)
The 3rd chapter of A.A. Milne's "Winnie-the-Pooh" is titled
"In which Pooh & Piglet Go Hunting & Nearly Catch a Woozle."
The characters find footprints in the snow, deduce the presence of a 'Woozle,' which they track.
But they're tracking their own footprints.
Let's talk about 'WOOZLE EFFECT'.
"In which Pooh & Piglet Go Hunting & Nearly Catch a Woozle."
The characters find footprints in the snow, deduce the presence of a 'Woozle,' which they track.
But they're tracking their own footprints.
Let's talk about 'WOOZLE EFFECT'.
November 29, 2025 at 5:05 PM
The 3rd chapter of A.A. Milne's "Winnie-the-Pooh" is titled
"In which Pooh & Piglet Go Hunting & Nearly Catch a Woozle."
The characters find footprints in the snow, deduce the presence of a 'Woozle,' which they track.
But they're tracking their own footprints.
Let's talk about 'WOOZLE EFFECT'.
"In which Pooh & Piglet Go Hunting & Nearly Catch a Woozle."
The characters find footprints in the snow, deduce the presence of a 'Woozle,' which they track.
But they're tracking their own footprints.
Let's talk about 'WOOZLE EFFECT'.
Reposted by Tanja Schlemm (she/her)
Africa’s forests have joined the Brazilian Amazon and Australian forests in becoming carbon sources rather than sinks. Around 2010 the previous storage of our carbon emissions flipped, mainly through deforestation and degradation.
www.nature.com/articles/s41...
#climatechange #deforestation #Africa
www.nature.com/articles/s41...
#climatechange #deforestation #Africa
Loss of tropical moist broadleaf forest has turned Africa’s forests from a carbon sink into a source - Scientific Reports
Africa’s forests and woody savannas have historically acted as a carbon sink, removing atmospheric carbon and storing it as biomass. However, our novel analysis reveals a critical transition from a ca...
www.nature.com
November 30, 2025 at 9:12 AM
Africa’s forests have joined the Brazilian Amazon and Australian forests in becoming carbon sources rather than sinks. Around 2010 the previous storage of our carbon emissions flipped, mainly through deforestation and degradation.
www.nature.com/articles/s41...
#climatechange #deforestation #Africa
www.nature.com/articles/s41...
#climatechange #deforestation #Africa
Reposted by Tanja Schlemm (she/her)
AI makes everything worse, and science and all of us stupid.
Authored by AI, reviewed by AI, edited by AI, published by AI. Next? cited by AI.
Authored by AI, reviewed by AI, edited by AI, published by AI. Next? cited by AI.
"Runctitiononal features"? "Medical fymblal"? "1 Tol Line storee"? This gets worse the longer you look at it. But it's got to be good, because it was published in Nature Scientific Reports last week: www.nature.com/articles/s41... h/t @asa.tsbalans.se
November 28, 2025 at 7:02 AM
AI makes everything worse, and science and all of us stupid.
Authored by AI, reviewed by AI, edited by AI, published by AI. Next? cited by AI.
Authored by AI, reviewed by AI, edited by AI, published by AI. Next? cited by AI.
Reposted by Tanja Schlemm (she/her)
The East Antarctic continental shelf is central to the #climate system yet remains one of the most poorly known regions of the global ocean.
So #Antarctic scientists in Japan and Australia have produced this ambitious forward-looking research plan.
▶️ aappartnership.org.au/wp-content/u...
So #Antarctic scientists in Japan and Australia have produced this ambitious forward-looking research plan.
▶️ aappartnership.org.au/wp-content/u...
November 28, 2025 at 5:32 AM
The East Antarctic continental shelf is central to the #climate system yet remains one of the most poorly known regions of the global ocean.
So #Antarctic scientists in Japan and Australia have produced this ambitious forward-looking research plan.
▶️ aappartnership.org.au/wp-content/u...
So #Antarctic scientists in Japan and Australia have produced this ambitious forward-looking research plan.
▶️ aappartnership.org.au/wp-content/u...
Reposted by Tanja Schlemm (she/her)
I really wish we'd stop calling them climate "skeptics" or "vaccine skeptics", if you jump off a cliff we don't call you a "gravity skeptic"
November 25, 2025 at 8:18 PM
I really wish we'd stop calling them climate "skeptics" or "vaccine skeptics", if you jump off a cliff we don't call you a "gravity skeptic"
Reposted by Tanja Schlemm (she/her)
What’s it like doing fieldwork in Antarctica? 🥶 Sarah Shackleton and @blueicedude.bsky.social from @princeton.edu can answer that.
They just found a 6-million-year-old ice core—a key piece to improve our current climate models!
My story for @eos.org
eos.org/articles/new...
They just found a 6-million-year-old ice core—a key piece to improve our current climate models!
My story for @eos.org
eos.org/articles/new...
New Lessons from Old Ice: How We Understand Past (and Future) Heating - Eos
Fragments of blue ice up to 6 million years old—the oldest ever found—offer key insights into Earth’s warming cycles. Researchers are using these ancient data to refine models of our future climate.
eos.org
November 25, 2025 at 9:49 PM
What’s it like doing fieldwork in Antarctica? 🥶 Sarah Shackleton and @blueicedude.bsky.social from @princeton.edu can answer that.
They just found a 6-million-year-old ice core—a key piece to improve our current climate models!
My story for @eos.org
eos.org/articles/new...
They just found a 6-million-year-old ice core—a key piece to improve our current climate models!
My story for @eos.org
eos.org/articles/new...
Reposted by Tanja Schlemm (she/her)
Happy to see this out! Meltwater can delay future surface warming, and its interannual variations impact ocean stratification & overturning. This effect is usually absent from models.
Including it as forcing may lead to more realistic simulation of surface temperature and sea ice trends🧊🌊 (1/7)
Including it as forcing may lead to more realistic simulation of surface temperature and sea ice trends🧊🌊 (1/7)
Finally out! The outcome of a virtual workshop in Feb 2024 with modelers and observationalists to put together data and protocols to include historical changes in ice sheet/ice shelf discharge in CMIP models. Hopefully not too late for some CMIP7 runs!
gmd.copernicus.org/articles/18/...
gmd.copernicus.org/articles/18/...
Datasets and protocols for including anomalous freshwater from melting ice sheets in climate simulations
Abstract. Anomalous freshwater fluxes from the Greenland and Antarctic ice sheets and ice shelves are impacting the surrounding oceans, and we need to be able to account for these effects in climate m...
gmd.copernicus.org
November 8, 2025 at 3:52 PM
Happy to see this out! Meltwater can delay future surface warming, and its interannual variations impact ocean stratification & overturning. This effect is usually absent from models.
Including it as forcing may lead to more realistic simulation of surface temperature and sea ice trends🧊🌊 (1/7)
Including it as forcing may lead to more realistic simulation of surface temperature and sea ice trends🧊🌊 (1/7)
Reposted by Tanja Schlemm (she/her)
“We have observational evidence and ocean modeling results to document that kilometer-scale seawater intrusions beneath grounded ice generate a high melt in the [grounding zone of Thwaites Glacier].”
www.pnas.org/doi/full/10....
www.pnas.org/doi/full/10....
Contrasting melt regime in the Ice Grounding Zone of Thwaites Glacier, West Antarctica | PNAS
The contribution of Thwaites Glacier, Antarctica, to sea level rise is influenced
by how quickly warm salty seawater of Circumpolar Deep Water orig...
www.pnas.org
November 24, 2025 at 3:33 PM
“We have observational evidence and ocean modeling results to document that kilometer-scale seawater intrusions beneath grounded ice generate a high melt in the [grounding zone of Thwaites Glacier].”
www.pnas.org/doi/full/10....
www.pnas.org/doi/full/10....
Reposted by Tanja Schlemm (she/her)
Franz Josef Glacier - Kā Roimata o Hine Hukatere
ca 1867 | 2022
Impressive comparison between the first known photograph taken of one of the most iconic NZ glaciers and current situation! 🧊🔥
The rock on the right is Sentinel Rock, one of the roches moutonnées in the glacier forefield
1/
ca 1867 | 2022
Impressive comparison between the first known photograph taken of one of the most iconic NZ glaciers and current situation! 🧊🔥
The rock on the right is Sentinel Rock, one of the roches moutonnées in the glacier forefield
1/
November 23, 2025 at 6:07 PM
Franz Josef Glacier - Kā Roimata o Hine Hukatere
ca 1867 | 2022
Impressive comparison between the first known photograph taken of one of the most iconic NZ glaciers and current situation! 🧊🔥
The rock on the right is Sentinel Rock, one of the roches moutonnées in the glacier forefield
1/
ca 1867 | 2022
Impressive comparison between the first known photograph taken of one of the most iconic NZ glaciers and current situation! 🧊🔥
The rock on the right is Sentinel Rock, one of the roches moutonnées in the glacier forefield
1/
Reposted by Tanja Schlemm (she/her)
Many people think about cold in Northern Europe if the Atlantic Ocean current system #AMOC fails. But that wouldn’t be the only problem for Europe by far.
This new study shows that severe drought is another one. 🌊
This new study shows that severe drought is another one. 🌊
📢 New paper on the impacts of AMOC collapse on European hydroclimate. 🌊
We find an AMOC collapse would exacerbate drought conditions across Europe, linked to reduced precipitation. In combination with climate change droughts are expected to become more frequent and severe.
doi.org/10.5194/hess...
We find an AMOC collapse would exacerbate drought conditions across Europe, linked to reduced precipitation. In combination with climate change droughts are expected to become more frequent and severe.
doi.org/10.5194/hess...
Changing European hydroclimate under a collapsed AMOC in the Community Earth System Model
Abstract. The Atlantic Meridional Overturning Circulation (AMOC) is expected to weaken or even collapse under anthropogenic climate change. Given the importance of the AMOC in the present-day climate,...
doi.org
November 22, 2025 at 5:52 AM
Many people think about cold in Northern Europe if the Atlantic Ocean current system #AMOC fails. But that wouldn’t be the only problem for Europe by far.
This new study shows that severe drought is another one. 🌊
This new study shows that severe drought is another one. 🌊
Reposted by Tanja Schlemm (she/her)
Lets be clear: Tehran's situation a result of #climatechange
Iran's drought explicitly tied to human-induced climate change driven by global warming
The drought in Iran, and across the Euphrates-Tigris basin, results from increasing temperatures, and so evaporation, and reducing precipitation
#COP30
Iran's drought explicitly tied to human-induced climate change driven by global warming
The drought in Iran, and across the Euphrates-Tigris basin, results from increasing temperatures, and so evaporation, and reducing precipitation
#COP30
“What once sounded unthinkable is now being said openly: Tehran is not viable; and evacuation orders are imminent.
As I wrote before, President Masoud Pezeshkian himself said that it might be necessary to relocate Tehranis in large number.” open.substack.com/pub/peterfra...
As I wrote before, President Masoud Pezeshkian himself said that it might be necessary to relocate Tehranis in large number.” open.substack.com/pub/peterfra...
Makran or Bust: Tehran's water crisis gets worse
Ten days ago I wrote that Tehran was approaching a point where warnings, pressure cuts and appeals to save water would no longer be enough.
open.substack.com
November 23, 2025 at 12:05 AM
Lets be clear: Tehran's situation a result of #climatechange
Iran's drought explicitly tied to human-induced climate change driven by global warming
The drought in Iran, and across the Euphrates-Tigris basin, results from increasing temperatures, and so evaporation, and reducing precipitation
#COP30
Iran's drought explicitly tied to human-induced climate change driven by global warming
The drought in Iran, and across the Euphrates-Tigris basin, results from increasing temperatures, and so evaporation, and reducing precipitation
#COP30
Reposted by Tanja Schlemm (she/her)
At present the issue is how to reinforce existing infrastructure or fortify shoreline, or relocate, Indigenous villages. In future decades major coastal cities around the world will face the same dilemma. Metres of sea-level rise are committed, even if we succeed in reaching net zero.
Storms that battered Alaska’s western coast this fall have brought renewed attention to low-lying Indigenous villages left increasingly vulnerable by climate change.
Alaska Native villages have few options and little US help as climate change devours their land
Storms that battered Alaska’s western coast this fall have brought renewed attention to low-lying Indigenous villages left increasingly vulnerable by climate change.
bit.ly
November 23, 2025 at 8:12 AM
At present the issue is how to reinforce existing infrastructure or fortify shoreline, or relocate, Indigenous villages. In future decades major coastal cities around the world will face the same dilemma. Metres of sea-level rise are committed, even if we succeed in reaching net zero.
Reposted by Tanja Schlemm (she/her)
This is a remarkable paper on the climate-induced heatwave death in Europe and how they will increase in a warming world.
www.nature.com/articles/s41...
www.nature.com/articles/s41...
Increasing risk of mass human heat mortality if historical weather patterns recur - Nature Climate Change
The authors couple calculations of historical heatwave intensity at present and future global temperatures with exposure–response functions to quantify mortality from extreme heat events in Europe. Th...
www.nature.com
November 23, 2025 at 9:10 AM
This is a remarkable paper on the climate-induced heatwave death in Europe and how they will increase in a warming world.
www.nature.com/articles/s41...
www.nature.com/articles/s41...
Reposted by Tanja Schlemm (she/her)
“…submesoscales account for one-fifth of the total submarine melt variance in the area and highlight a positive feedback loop between submesoscale motions and submarine melting.”
doi.org/10.1038/s415...
doi.org/10.1038/s415...
Ocean submesoscales as drivers of submarine melting within Antarctic ice cavities - Nature Geoscience
Submesoscale ocean features deliver heat beneath Thwaites Ice Shelf and contribute to submarine melting, according to numerical modelling combined with available observations.
doi.org
November 20, 2025 at 1:10 PM
“…submesoscales account for one-fifth of the total submarine melt variance in the area and highlight a positive feedback loop between submesoscale motions and submarine melting.”
doi.org/10.1038/s415...
doi.org/10.1038/s415...
Reposted by Tanja Schlemm (she/her)
This is the problem with trying to inspire hope using the message "we have the solutions": such a message may inspire the kind of techno-optimism that actually fosters political *dis*engagement.
1/n
1/n
⚠️ When “technology will save us” becomes a climate risk!
A new paper from great colleagues takes a careful look at techno-optimism — the belief that technology will largely solve climate change — and what it means for real-world climate action.
(1/4)👇
osf.io/preprints/ps...
A new paper from great colleagues takes a careful look at techno-optimism — the belief that technology will largely solve climate change — and what it means for real-world climate action.
(1/4)👇
osf.io/preprints/ps...
November 19, 2025 at 7:32 PM
This is the problem with trying to inspire hope using the message "we have the solutions": such a message may inspire the kind of techno-optimism that actually fosters political *dis*engagement.
1/n
1/n
Reposted by Tanja Schlemm (she/her)
Things that will get you kicked out of academia forever:
- taking maternity leave at the wrong time
- spending too much time with your kids
- reporting harassment
- not moving every 2-3 years
- taking a partner's job/preferences into account
- mouthing off before tenure
- taking maternity leave at the wrong time
- spending too much time with your kids
- reporting harassment
- not moving every 2-3 years
- taking a partner's job/preferences into account
- mouthing off before tenure
A guy makes ONE tiny mistake (has a years-long friendship with the world's worst sex trafficker; brags about sexually harassing colleagues; is racist; says women are stupid) and his whole LIFE is blown up (does slightly fewer speaking engagements; keeps teaching at #1 university)??!?!?!?!?!
So Harvard is keeping this guy, but Claudine Gay had to step down over ginned up plagiarism accusations and bad-faith accusations of anti-Semitism.
Got it.
Got it.
November 18, 2025 at 3:52 PM
Things that will get you kicked out of academia forever:
- taking maternity leave at the wrong time
- spending too much time with your kids
- reporting harassment
- not moving every 2-3 years
- taking a partner's job/preferences into account
- mouthing off before tenure
- taking maternity leave at the wrong time
- spending too much time with your kids
- reporting harassment
- not moving every 2-3 years
- taking a partner's job/preferences into account
- mouthing off before tenure
Reposted by Tanja Schlemm (she/her)
New paper alert ! 🙂
Happy to share our new study published in The Cryosphere !
doi.org/10.5194/tc-1...
We modelled the evolution of the Greenland Ice Sheet from the LGM (24 ka) to the present and learned a lot on its former history and dynamics !
@jeremyely.bsky.social @chrisdclark.bsky.social
Happy to share our new study published in The Cryosphere !
doi.org/10.5194/tc-1...
We modelled the evolution of the Greenland Ice Sheet from the LGM (24 ka) to the present and learned a lot on its former history and dynamics !
@jeremyely.bsky.social @chrisdclark.bsky.social
November 18, 2025 at 2:35 PM
New paper alert ! 🙂
Happy to share our new study published in The Cryosphere !
doi.org/10.5194/tc-1...
We modelled the evolution of the Greenland Ice Sheet from the LGM (24 ka) to the present and learned a lot on its former history and dynamics !
@jeremyely.bsky.social @chrisdclark.bsky.social
Happy to share our new study published in The Cryosphere !
doi.org/10.5194/tc-1...
We modelled the evolution of the Greenland Ice Sheet from the LGM (24 ka) to the present and learned a lot on its former history and dynamics !
@jeremyely.bsky.social @chrisdclark.bsky.social
Reposted by Tanja Schlemm (she/her)
The #ISMIP7 ice-ocean Antarctic focus group is recruiting a 2.5 year postdoc on ice-shelf basal melting at Northumbria University, Newcastle, UK. A great way to develop international collaborations and contribute to the improvement of sea level projections!
work4.northumbria.ac.uk#en/sites/CX_...
work4.northumbria.ac.uk#en/sites/CX_...
work4.northumbria.ac.uk
November 18, 2025 at 10:22 PM
The #ISMIP7 ice-ocean Antarctic focus group is recruiting a 2.5 year postdoc on ice-shelf basal melting at Northumbria University, Newcastle, UK. A great way to develop international collaborations and contribute to the improvement of sea level projections!
work4.northumbria.ac.uk#en/sites/CX_...
work4.northumbria.ac.uk#en/sites/CX_...
Reposted by Tanja Schlemm (she/her)
The amount of ice flowing from Thwaites Glacier in West Antarctica has doubled in the span of three decades. These satellite images from 2001 and 2019 show the fracture and retreat of the glacier ice tongue floating on the Amundsen Sea, as it's melted from below.
🛰️ NASA
🛰️ NASA
November 19, 2025 at 3:48 AM
The amount of ice flowing from Thwaites Glacier in West Antarctica has doubled in the span of three decades. These satellite images from 2001 and 2019 show the fracture and retreat of the glacier ice tongue floating on the Amundsen Sea, as it's melted from below.
🛰️ NASA
🛰️ NASA
Reposted by Tanja Schlemm (she/her)
The Hektoria Glacier on the Antarctic Peninsula retreated by at least 8 km in two months, a rate nearly 10 times faster than previously measured for a grounded glacier, according to a study in Nature Geoscience. go.nature.com/4nETBYJ ⚒️ 🧪
November 13, 2025 at 2:29 AM
The Hektoria Glacier on the Antarctic Peninsula retreated by at least 8 km in two months, a rate nearly 10 times faster than previously measured for a grounded glacier, according to a study in Nature Geoscience. go.nature.com/4nETBYJ ⚒️ 🧪
Reposted by Tanja Schlemm (she/her)
Average temperature departures by month in the #Antarctic since the year 1940.
Data from @copernicusecmwf.bsky.social ERA5 reanalysis.
Data from @copernicusecmwf.bsky.social ERA5 reanalysis.
November 11, 2025 at 11:57 PM
Average temperature departures by month in the #Antarctic since the year 1940.
Data from @copernicusecmwf.bsky.social ERA5 reanalysis.
Data from @copernicusecmwf.bsky.social ERA5 reanalysis.
Reposted by Tanja Schlemm (she/her)
Reposted by Tanja Schlemm (she/her)
Filming at an abandoned uranium mine in Arizona. The mining waste is uncontained, open to the winds. Professor Kearfott, University of Michigan, telks me the Geiger counter readings I took here are similar to those remaining around Chernobyl.
vimeo.com/ondemand/thi...
vimeo.com/ondemand/thi...
November 17, 2025 at 7:05 PM
Filming at an abandoned uranium mine in Arizona. The mining waste is uncontained, open to the winds. Professor Kearfott, University of Michigan, telks me the Geiger counter readings I took here are similar to those remaining around Chernobyl.
vimeo.com/ondemand/thi...
vimeo.com/ondemand/thi...
Reposted by Tanja Schlemm (she/her)
The increasing participation of fossil-fuel lobbyists in recent COP meetings is concerning. Climate solutions should be shaped by those committed to real progress, not by those invested in slowing it down.
Fossil fuel lobbyists outnumber all Cop30 delegations except Brazil, report says
Fossil fuel lobbyists outnumber all Cop30 delegations except Brazil, report says
One in every 25 participants at 2025 UN climate summit is a fossil fuel lobbyist, according to Kick Big Polluters Out
More than 1,600 fossil fuel lobbyists have been granted access to the Cop30 climate negotiations in Belém, significantly outnumbering every single country’s delegation apart from the host Brazil, new analysis has found.
One in every 25 participants at this year’s UN climate summit is a fossil fuel lobbyist, according to the analysis by the Kick Big Polluters Out (KBPO) coalition, raising serious questions about the corporate capture and credibility of the annual Cop negotiations. Continue reading...
www.theguardian.com
November 14, 2025 at 3:34 PM
The increasing participation of fossil-fuel lobbyists in recent COP meetings is concerning. Climate solutions should be shaped by those committed to real progress, not by those invested in slowing it down.
Reposted by Tanja Schlemm (she/her)
"...10yrs ago, the app estimated that the global temp was already 0.98°C above pre-industrial ave. & would breach the 1.5°C threshold in 2045. Today, the same tool estimates that we have reached a global ave. of 1.25°C & will be at 1.5°C over pre-industrial levels in May 2029"
#FasterThanExpected
#FasterThanExpected
Acceleration
“In 2015 our projected deadline for reaching 1.5°C was 27 years away. Now that threshold is only 4 years away – 23 years closer. This striking change suggests that global warming has accelerated quickly in recent years.”
Source: climate.copernicus.eu/rapid-approa...
#ClimateCrisis
“In 2015 our projected deadline for reaching 1.5°C was 27 years away. Now that threshold is only 4 years away – 23 years closer. This striking change suggests that global warming has accelerated quickly in recent years.”
Source: climate.copernicus.eu/rapid-approa...
#ClimateCrisis
November 16, 2025 at 4:57 AM
"...10yrs ago, the app estimated that the global temp was already 0.98°C above pre-industrial ave. & would breach the 1.5°C threshold in 2045. Today, the same tool estimates that we have reached a global ave. of 1.25°C & will be at 1.5°C over pre-industrial levels in May 2029"
#FasterThanExpected
#FasterThanExpected