Florian U. Jehn
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florianjehn.fediscience.org.ap.brid.gy
Florian U. Jehn
@florianjehn.fediscience.org.ap.brid.gy
5 followers 1 following 38 posts
Aggressively agreeable | currently exploring the overlap of #ExistentialRisk, #FoodSecurity, #NuclearWinter and #Collapse | also quite interested in […]

🌉 bridged from https://fediscience.org/@florianjehn on the fediverse by https://fed.brid.gy/
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Reposted by Florian U. Jehn
joeroe.archaeo.social.ap.brid.gy
‘AltMetric’-style services, which track citations to academic papers outside of academic literature—so in the news, social media, etc.—have been quick to incorporate #bluesky posts, but I’ve yet to see one that includes the #fediverse

I can see that (real) decentralisation makes it harder to […]
Original post on archaeo.social
archaeo.social
February 9, 2026 at 8:43 AM
florianjehn.fediscience.org.ap.brid.gy
New paper is out!

We identified the worst crop shock every country experienced since 1961: the global average was −29%, with Botswana even losing 80% in a single year. Climate—especially drought—was the leading cause, although conflict is also a major […]

[Original post on fediscience.org]
A global map with countries being colored by the severity of their worst crop production shocks. Especially, in Africa many countries experienced severe shocks, but on other continents as well.
February 4, 2026 at 9:54 AM
Reposted by Florian U. Jehn
florianjehn.fediscience.org.ap.brid.gy
Had a great conversation with Samuel Arbesman on the podcast "The Orthogonal Bet" about all things collapse. If you are curious about the interdisciplinary nature of collapse studies, how it connects history to global catastrophic risk, and how societal […]

[Original post on fediscience.org]
An old church, partly collapse due to bombing in the First World War.
January 29, 2026 at 7:03 AM
florianjehn.fediscience.org.ap.brid.gy
Had a great conversation with Samuel Arbesman on the podcast "The Orthogonal Bet" about all things collapse. If you are curious about the interdisciplinary nature of collapse studies, how it connects history to global catastrophic risk, and how societal […]

[Original post on fediscience.org]
An old church, partly collapse due to bombing in the First World War.
January 29, 2026 at 7:03 AM
Reposted by Florian U. Jehn
florianjehn.fediscience.org.ap.brid.gy
One important factor to understanding the impact of global catastrophes is economics. How might agricultural prices rise? What are the general economic outlooks? In the next post in my living literature review I try to explore exactly this. The literature is […]

[Original post on fediscience.org]
An old French poster to sell national bonds after the First World War. Golden statue in the background, ruins in the foreground.
January 14, 2026 at 10:08 AM
florianjehn.fediscience.org.ap.brid.gy
One important factor to understanding the impact of global catastrophes is economics. How might agricultural prices rise? What are the general economic outlooks? In the next post in my living literature review I try to explore exactly this. The literature is […]

[Original post on fediscience.org]
An old French poster to sell national bonds after the First World War. Golden statue in the background, ruins in the foreground.
January 14, 2026 at 10:08 AM
Reposted by Florian U. Jehn
florianjehn.fediscience.org.ap.brid.gy
Next round of updates for my #LivingLiteratureReview. This means I go back to the old posts and add new papers I found, to make sure that everything stays as up to date as possible. Posts which got updated this time:
* Mapping out collapse research ( […]

[Original post on fediscience.org]
Baguettes spread out on a table. These symbolize the bread rations in France in WW1.
December 17, 2025 at 9:12 AM
florianjehn.fediscience.org.ap.brid.gy
Next round of updates for my #LivingLiteratureReview. This means I go back to the old posts and add new papers I found, to make sure that everything stays as up to date as possible. Posts which got updated this time:
* Mapping out collapse research ( […]

[Original post on fediscience.org]
Baguettes spread out on a table. These symbolize the bread rations in France in WW1.
December 17, 2025 at 9:12 AM
Reposted by Florian U. Jehn
florianjehn.fediscience.org.ap.brid.gy
For #globalwarming it seems that we are on a pathway to be clearly above 1.5°C and arguably also clearly above 2°C. In my new post I summarize research that highlights why this is the case and also how much of these higher temperatures ranges we really have […]

[Original post on fediscience.org]
A orange tinted, old picture from an old house near a river. There are snow capped mountains in the background.
November 30, 2025 at 4:32 PM
florianjehn.fediscience.org.ap.brid.gy
For #globalwarming it seems that we are on a pathway to be clearly above 1.5°C and arguably also clearly above 2°C. In my new post I summarize research that highlights why this is the case and also how much of these higher temperatures ranges we really have […]

[Original post on fediscience.org]
A orange tinted, old picture from an old house near a river. There are snow capped mountains in the background.
November 30, 2025 at 4:32 PM
Reposted by Florian U. Jehn
brucelawson.vivaldi.net.ap.brid.gy
"In August 2025, Google announced that starting next year, it will no longer be possible to develop apps for the Android platform without first registering centrally with Google." What tis means for your rights, and how you can help: https://keepandroidopen.org
Keep Android Open
Advocating for Android as a free, open platform for everyone to build apps on.
keepandroidopen.org
October 31, 2025 at 11:54 AM
Reposted by Florian U. Jehn
florianjehn.fediscience.org.ap.brid.gy
Remember the beautiful auroras last year? These occur when solar particles interact with Earth's magnetic field. When #earth is hit by large amounts of these particles, this is called a #geomagneticstorm. Geomagnetic storms can induce currents into the […]

[Original post on fediscience.org]
A dark and small alley with houses high up on both sides. In the middle of the picture is a street lamp which is hit by sun light from the side and casts an interesting shadow on one of the buildings.
October 29, 2025 at 10:45 AM
florianjehn.fediscience.org.ap.brid.gy
Remember the beautiful auroras last year? These occur when solar particles interact with Earth's magnetic field. When #earth is hit by large amounts of these particles, this is called a #geomagneticstorm. Geomagnetic storms can induce currents into the […]

[Original post on fediscience.org]
A dark and small alley with houses high up on both sides. In the middle of the picture is a street lamp which is hit by sun light from the side and casts an interesting shadow on one of the buildings.
October 29, 2025 at 10:45 AM
florianjehn.fediscience.org.ap.brid.gy
I have written a new draft for my blog about the potential damages that can be caused by a #geomagneticstorm. I am looking for someone familiar with this topic to review it for accuracy. If this is you, please write me a message. If this is not you, please consider boosting this message.
October 11, 2025 at 5:41 PM
Reposted by Florian U. Jehn
florianjehn.fediscience.org.ap.brid.gy
New post on my blog. I summarized Peter Turchin's book "End Times: Elites, Counter-Elites, and the Path of Political Disintegration". The post gives an overview of how #structuraldemographictheory works and how this explains the present political and social […]

[Original post on fediscience.org]
A large, dark blue curtain halfway hiding a large, somewhat modern looking iron gate. An out of focus person is standing at the edge of the curtain.
October 1, 2025 at 11:38 AM
florianjehn.fediscience.org.ap.brid.gy
New post on my blog. I summarized Peter Turchin's book "End Times: Elites, Counter-Elites, and the Path of Political Disintegration". The post gives an overview of how #structuraldemographictheory works and how this explains the present political and social […]

[Original post on fediscience.org]
A large, dark blue curtain halfway hiding a large, somewhat modern looking iron gate. An out of focus person is standing at the edge of the curtain.
October 1, 2025 at 11:38 AM
Reposted by Florian U. Jehn
florianjehn.fediscience.org.ap.brid.gy
(1/4) We modeled how global food trade would collapse after catastrophic events like nuclear war or infrastructure loss. It matters enormously where damage occurs, not just how much. Especially, in nuclear winter many countries would loose the majority of […]

[Original post on fediscience.org]
A three panel figure showing the distribution of wheat trading communities now, after a nuclear war and after a loss of industrial production. The impacts of the nuclear war are considerably larger with many countries having to switch their trade community.
September 30, 2025 at 10:23 AM
florianjehn.fediscience.org.ap.brid.gy
(4/4) Our model is open source and available for other researchers to explore scenarios: https://github.com/allfed/pytradeshifts

This is urgent work. The probability of at least one major food system shock this century is high and rising. We need better preparation strategies.

#OpenScience […]
Original post on fediscience.org
fediscience.org
September 30, 2025 at 10:28 AM
florianjehn.fediscience.org.ap.brid.gy
(3/4) Even "smaller" nuclear wars have massive trade impacts. At just 5 Tg of soot, some countries lose 50% of #maize imports. At 16 Tg, many countries face major import losses across all major crops.

This matters for nuclear policy: limiting escalation is crucial even if conflict begins. The […]
Original post on fediscience.org
fediscience.org
September 30, 2025 at 10:28 AM
florianjehn.fediscience.org.ap.brid.gy
(2/4) Even when two catastrophes cause similar global yield losses, their effects on trade are dramatically different.

Abrupt sunlight reduction (#nuclearwar, #supervolcano) concentrates damage in high-latitude major exporters → severe trade disruption […]

[Original post on fediscience.org]
Global map showing the distribution of relative food import losses for abrupt sunlight reduction scenarios and global catastrophic infrastructure loss. Northern Hemisphere countries in nuclear war scenario loose most.
September 30, 2025 at 10:26 AM
florianjehn.fediscience.org.ap.brid.gy
(1/4) We modeled how global food trade would collapse after catastrophic events like nuclear war or infrastructure loss. It matters enormously where damage occurs, not just how much. Especially, in nuclear winter many countries would loose the majority of […]

[Original post on fediscience.org]
A three panel figure showing the distribution of wheat trading communities now, after a nuclear war and after a loss of industrial production. The impacts of the nuclear war are considerably larger with many countries having to switch their trade community.
September 30, 2025 at 10:23 AM
Reposted by Florian U. Jehn
florianjehn.fediscience.org.ap.brid.gy
New preprint: "The Largest Crop Production Shocks: Magnitude, Causes and Frequency"

Large #cropfailures happen regularly around the world, threatening #foodsecurity. We analyzed sixty years of global crop production data and found that every country has […]

[Original post on fediscience.org]
World map that shows the largest crop production shocks. These range from around -10 % in countries like China and up to -80% in some parts of Africa. The dataset is from 1961-2023.
September 4, 2025 at 5:37 PM
florianjehn.fediscience.org.ap.brid.gy
New preprint: "The Largest Crop Production Shocks: Magnitude, Causes and Frequency"

Large #cropfailures happen regularly around the world, threatening #foodsecurity. We analyzed sixty years of global crop production data and found that every country has […]

[Original post on fediscience.org]
World map that shows the largest crop production shocks. These range from around -10 % in countries like China and up to -80% in some parts of Africa. The dataset is from 1961-2023.
September 4, 2025 at 5:37 PM
Reposted by Florian U. Jehn
florianjehn.fediscience.org.ap.brid.gy
#climatechange, #nuclearwinter, and #stratosphericaerosolinjection are all human-made interventions in the climate system. They share the potential to be massively disruptive to the habitability of this planet. Usually, we see them as separate catastrophes […]

[Original post on fediscience.org]
Abandoned trenches in the desert.
September 3, 2025 at 9:05 AM
florianjehn.fediscience.org.ap.brid.gy
#climatechange, #nuclearwinter, and #stratosphericaerosolinjection are all human-made interventions in the climate system. They share the potential to be massively disruptive to the habitability of this planet. Usually, we see them as separate catastrophes […]

[Original post on fediscience.org]
Abandoned trenches in the desert.
September 3, 2025 at 9:05 AM