Flavio Lehner

@climateflavors.bsky.social

2K followers 470 following 180 posts

Climate Scientist
Assistant Professor @ Cornell University
Chief Climate Scientist @ Polar Bears International
https://flaviolehner.eas.cornell.edu/

Videos

Environmental science 55%

Geography 18%

Posts Replies Media Videos

Flavio Lehner @climateflavors.bsky.social · 5h

Cc @sillin.bsky.social

Scott Bachmeier @wisc-satellite.bsky.social · 16h

The 50th Anniversary of the Wreck of the Edmund Fitzgerald: A New Perspective on an Old Storm: cimss.ssec.wisc.edu/satellite-bl...

Reposted by Katharine Hayhoe, Ben Bond‐Lamberty, Flavio Lehner

Scott Bachmeier @wisc-satellite.bsky.social · 16h

The 50th Anniversary of the Wreck of the Edmund Fitzgerald: A New Perspective on an Old Storm: cimss.ssec.wisc.edu/satellite-bl...

Reposted by Flavio Lehner

Nate Howes TWN @natetwnclimate.bsky.social · 8d

As part of #PolarBearWeek (Nov. 2-8), a new AI-based system from @polarbearsinternational.org, tested in the Far North for several years, officially launched to alert locales of animals nearby to deter human-wildlife conflicts. @vfennalvarado.bsky.social www.theweathernetwork.com/en/news/natu...

Bear-dar looks to prevent human-wildlife conflicts in the North - The Weather Network

As part of Polar Bear Week (Nov. 2-8), a new artificial intelligence-based system, which has been in a testing phase in the Far North for several years, has been officially launched to alert communiti...

www.theweathernetwork.com

Flavio Lehner @climateflavors.bsky.social · 8d

Next level!

Reposted by Flavio Lehner

Polar Bears International @polarbearsinternational.org · 8d

Good morning from the tundra 💙

Flavio Lehner @climateflavors.bsky.social · 10d

For our department Halloween party, I went as scary Stratospheric Aerosol Injection (SAI) - mostly to tease @danvisioni.bsky.social

Reposted by Peter Thorne, Flavio Lehner, Peter Jacobs

Tomer Burg @burgwx.bsky.social · 12d

Multi-panel view of the last few days of Hurricane Melissa:

↖️ GOES-19 infrared brightness temp
↗️ GOES-19 visible satellite
↙️ Hurricane hunter planes & flight paths
↘️ Recon-derived flight level wind swath
⬇️ Estimated minimum pressure from recon dropsondes

Reposted by Katharine Hayhoe, John Kennedy, Flavio Lehner , and 1 more Katharine Hayhoe, John Kennedy, Flavio Lehner, Blair Fix

Andrew Dessler @andrewdessler.com · 13d

this is a very impressive analysis of some of the statistical "oddities" in Pielke Jr's analysis that normalized climate impacts are declining. Everyone should read this.
economicsfromthetopdown.com/2025/10/26/r...

Roger Pielke Jr.’s Appallingly Bad Analysis of Billion Dollar Disasters – Economics from the Top Down

In a recent paper called Scientific integrity and U.S. “Billion Dollar Disasters”, Roger Pielke Jr. published a chart that's so bad I've devoted a whole essay to debunking it.

economicsfromthetopdown.com

Reposted by Peter Thorne, Flavio Lehner, Peter Jacobs

Zack Labe @zacklabe.com · 15d

For understanding climate change impacts to tropical cyclones in near-real time, explore our new attribution pages unique to each storm from @climatecentral.org: www.climatecentral.org/tropical-cyc...

"Climate change made the ocean temperatures along Melissa's path 500 to 700 times more likely."

Screenshot that says: "Climate Central analyzes real-time data to reveal the climate change story behind every named Atlantic storm. As storms form and strengthen, our data and visuals show how rising ocean temperatures — driven by climate change — fuel tropical cyclones and influence their intensity for Melissa, Lorenzo, Jerry, Imelda, and Humberto."

Reposted by Stefan Rahmstorf, Peter Thorne, Chris Smith , and 3 more Stefan Rahmstorf, Peter Thorne, Chris Smith, Flavio Lehner, Dominik Wiedenhofer, Stacy D. VanDeveer

Carl Schleussner @carlschleussner.bsky.social · 17d

Really important paper led by my @iiasa.ac.at colleague Alex Nauels www.nature.com/articles/s41...
“The difference between decisive climate action today and continued high emissions is not just measured in degrees of warming but also in meters of sea-level rise” 👏👏👏

Multi-century global and regional sea-level rise commitments from cumulative greenhouse gas emissions in the coming decades - Nature Climate Change

It is important to understand how much long-term sea-level rise is already committed due to historical and near-term emissions. Here the authors use a modelling framework to show how decisions on glob...

www.nature.com

Reposted by Valerie M. Delmotte, Anders Levermann, Flavio Lehner , and 2 more Valerie M. Delmotte, Anders Levermann, Flavio Lehner, Hisham Zerriffi, Cullen S. Hendrix

Climate Central @climatecentral.org · 19d

The Billion Dollar Weather and Climate Disaster dataset is back and now at @climatecentral.org!

Through the first half of 2025, there were 14 separate billion-dollar weather and climate disasters across the United States, costing $101.4 billion. 1/2
www.climatecentral.org/climate-serv...

Map of US with purple and blue icons over central US indicating severe weather billion dollar disaster events in 2025 and one fire in LA.

Reposted by Flavio Lehner

Nate Howes TWN @natetwnclimate.bsky.social · 20d

With the Arctic sea ice maintaining its trend of declining, average extent since the 1980s, there is another side to the story with a unique, slightly more positive statistic. @polarbearsinternational.org @climateflavors.bsky.social www.theweathernetwork.com/en/news/clim...

'Remarkable' trend happening in the Arctic, despite warming, since 2012 - The Weather Network

Despite the Arctic's worsening, ongoing warming, an unexpected trend has been uncovered: A 13-year streak of no new records for sea ice minimum. A climate scientist dives into the possible reasons why

www.theweathernetwork.com

Reposted by Peter Thorne, Gavin L. Foster, Fabrice Ardhuin , and 3 more Peter Thorne, Gavin L. Foster, Fabrice Ardhuin, Gavin A. Schmidt, Flavio Lehner, Steven French

Ed Hawkins @edhawkins.org · 25d

A request for weather interested volunteers!

Met Eireann would like to rescue millions of weather observations taken in Ireland over many decades that are still stuck on paper. #WeatherRescue

Anyone can help: www.zooniverse.org/projects/met...

Reposted by Pierre Friedlingstein, Peter Thorne, Michael Wehner , and 1 more Pierre Friedlingstein, Peter Thorne, Michael Wehner, Flavio Lehner

Dr. Genevieve Guenther (she/they) @doctorvive.bsky.social · Oct 10

The attack on @frediotto.bsky.social was seeded years ago by Roger Pielke Jr, who started arguing that this table from a recent @ipcc.bsky.social report proved that climate science cannot attribute extreme weather to climate change.

But Roger is of course lying. And we know this for 2 reasons.

🧵

CLIMATEWIRE
Climate critics try to discredit IPCC author for linking
disasters to global warming
By LESLEY CLARK, SARA SCHONHARDT, CHELSEA HARVEY | 10/09/2025
06:22 AM EDT Roger Pielke Jr. and oil industry supporters are attacking climate scientist Friederike Otto, whose
work has been used in lawsuits against polluters.

Table 12.12 | Emergence of CIDs in different time periods, as assessed in this section. The colour contesponds to the confidence of the region with the highest confidence: white cells indicate where evidence is lacking or the signal is not present, leading to overal bu confidence of an emerging signal.

Reposted by Flavio Lehner

David Ho @davidho.bsky.social · Oct 9

It seems there are two main reasons things haven’t gone completely to shit in the US: 1. Lawyers and the courts; 2. Journalists and the media. Most of us can’t do anything about the first, but we can support journalism. Stop complaining about paywalls and subscribe to news & donate to public media.

Reposted by Flavio Lehner

Nate Howes TWN @natetwnclimate.bsky.social · Oct 8

Thanks to @climateflavors.bsky.social of @polarbearsinternational.org for the assist. Study says billions of tonnes of defrosted carbon could get released into the atmosphere by 2100 due to melting permafrost, further adding to Earth's warming from more GHG. www.theweathernetwork.com/en/news/clim...

Melting permafrost could unload billions of tonnes of carbon by 2100 - The Weather Network

A new study says billions of tonnes of defrosted carbon could end up getting released into the atmosphere by 2100 as a result of melting permafrost, further adding to the planet's warming from more gr...

www.theweathernetwork.com

Reposted by Anthony Ricciardi, Flavio Lehner, Justin H. Kirkland , and 5 more Anthony Ricciardi, Flavio Lehner, Justin H. Kirkland, Jussi T. Eronen, Mirya R. Holman, Emily Grubert, Paul Nightingale, S. Laurel Weldon

Kevin J. Kircher @kevinjkircher.com · Oct 4

Sometimes I think about how from 1935-1975ish, Bell Labs produced an insane amount of revolutionary science and technology, including 11 Nobel Prizes, the transistor, UNIX, C, the laser, the solar cell, information theory, etc. The secret? Provide scientists with ample, steady, no-strings funding.

sites.stat.columbia.edu

Flavio Lehner @climateflavors.bsky.social · Sep 29

Fyi, you can have global entry with only a greencard.

Fingers crossed you don’t have to have any such discussion.

Reposted by Flavio Lehner

Nate Howes TWN @natetwnclimate.bsky.social · Sep 29

If there is one piece of good news regarding our planet's future, it's our ozone layer and ongoing shrinking of its hole. New @wmo-global.bsky.social report said Earth's protective ozone layer is healing and the hole in 2024 was smaller than in recent years. www.theweathernetwork.com/en/news/clim...

Smaller ozone hole in 2024 pushes Earth closer to seeing it vanish - The Weather Network

A new World Meteorological Organization (WMO) report offers good news about Earth's ozone layer, which is on the road to a recovery to 1980 values in the coming decades--a positive sign for the health...

www.theweathernetwork.com

Reposted by Flavio Lehner

Jeff Berardelli @weatherprof.bsky.social · Sep 29

This is why two hurricanes can not merge into a monster.
Watch as #Imelda’s growing outflow and sinking air impinges on #Humberto’s core, likely soon leading to weakening. Systems are now under 600 miles apart.

Reposted by Peter Thorne, Matthias Cuntz, Flavio Lehner , and 7 more Peter Thorne, Matthias Cuntz, Flavio Lehner, Colin Murray, Andrew Curry, Adrian Vickers, David Bartram, Henrik Skaug Sætra, Klaus Oschema, Renaud Morieux

Ben Sanderson @benmsanderson.bsky.social · Sep 29

Paris-Berlin sleeper: low carbon, 2 years old, constantly full, but currently losing SNCF a few million EUR/yr

Intl Jet fuel tax exemptions are 80 years old and cost the EU 22 million EUR/yr for the Paris-Berlin route alone.

And you're cutting... the sleeper?

www.theguardian.com/travel/2025/...

It’s goodnight Vienna as Paris sleeper train to Austria and Berlin hit by cuts

Some Nightjet services suspended from mid-December after French withdrawal amid public budget crisis

www.theguardian.com

Dave Vanness @djvanness.bsky.social · Sep 29

A lot of people think that every international student admitted means one fewer spot for domestic students, when the opposite is more likely true - the tuition revenue international students bring allows public universities to provide substantial discounts to domestic students, improving access.

Nick Fleisher @nickfleisher.bsky.social · Sep 29

30% drop year over year!

Amid visa restrictions, international freshmen enrollment plummets at UW-Madison

This year’s number of international freshmen is the lowest recorded since at least 2015.

www.jsonline.com

Reposted by Flavio Lehner, Joshua S. Weitz, Silvia Secchi , and 1 more Flavio Lehner, Joshua S. Weitz, Silvia Secchi, Jason Williams

Lauren Kuehne @omfishient.bsky.social · Sep 29

🧪 Were you one of the many thousands of STEM students (and mentors) impacted by the sudden change in #NSF #GRFP eligibility last week?

We created a petition to NSF leadership and Congress to reverse the changes - please sign and share your stories here!!

laurenkuehne.github.io/grfpChanges/

Petition to NSF to Restore Eligibility for the 2026 Graduate Research Fellowship Program Competition

laurenkuehne.github.io

Reposted by Flavio Lehner

Cristi Proistosescu @cristiproist.bsky.social · Sep 25

New paper out. In which we helped the folks at the Allen Institute for AI (AI2) show that their climate emulator does a good (though not perfect) job at reproducing E3SMs' response to different SST boundary conditions.

1/

agupubs.onlinelibrary.wiley.com/doi/full/10....

Applying the ACE2 Emulator to SST Green's Functions for the E3SMv3 Global Atmosphere Model

The Ai2 Climate Emulator broadly captures the top-of-atmosphere (TOA) radiative response to local sea surface temperature (SST) anomalies ACE and EAMv3's global TOA radiation sensitivity to all S...

agupubs.onlinelibrary.wiley.com

Reposted by A. E. Dessler, Gavin A. Schmidt, Flavio Lehner

AGU (American Geophysical Union) @agu.org · Sep 25

📢 Submissions are now open for the U.S. Climate Collection, a joint @theAGU + @ametsoc initiative.

This special collection will publish U.S.-focused climate assessment science that’s free to read, ensuring rigorous, accessible science informs decisions for years to come.

🔗 buff.ly/1tHUSLC

Reposted by Gavin A. Schmidt, Flavio Lehner

James Goodwin @jamesgoodwin.bsky.social · Sep 24

"... Zeldin intends to sign off next week on the final policy and legal justifications for repealing the so-called endangerment finding and Biden-era climate rules for cars and trucks... before agency staff have time to sift through all public comments...." subscriber.politicopro.com/article/eene...

E&E News: Internal docs: Zeldin races ahead without analysis in endangerment rollback

The EPA administrator plans to sign off on the repeal's policy and legal justifications before his staff finishes the regulatory impact analysis.

subscriber.politicopro.com

Reposted by A. E. Dessler, Ben Bond‐Lamberty, Gavin A. Schmidt , and 10 more A. E. Dessler, Ben Bond‐Lamberty, Gavin A. Schmidt, Jesse H. Kroll, Julie L. Lockwood, Flavio Lehner, Lauren B. Buckley, Michael J. Allen, Dustin Mulvaney, Dawn J. Wright, Juan Rocha, Halley E. Froehlich, Beth Tellman

Climate.us @climate.us · Sep 23

🚨 NCA5 is now LIVE! 🚨

They took it down, but we've brought it back at: nca5.climate.us

Bookmark. 👏 this. 👏 page. 👏

This is just our first step in restoring trusted science information that Americans need to understand what's happening with the climate.

Reposted by Michael Wagner, Johannes Quaas, Jamie Hannaford , and 8 more Michael Wagner, Johannes Quaas, Jamie Hannaford, Ben Bond‐Lamberty, Gavin A. Schmidt, John Fasullo, Flavio Lehner, Jürgen Maier, James Connelly, Richard M. Carpiano, Alan McNally

Zeke Hausfather @hausfath.bsky.social · Sep 23

In a UN speech today, President Trump said that "all of these [climate] predictions were wrong".

Back in 2019 I led a research effort to digitize old climate model projections and assess how well they did. Turns out they got future warming pretty spot on!

Flavio Lehner @climateflavors.bsky.social · Sep 22

Sorry, I meant 5.0.2...

Flavio Lehner @climateflavors.bsky.social · Sep 22

Thanks and nice to see this, Tim! What's happening over North America in CRUTEM 5.1 minus 5.2? Just random variations in stations reporting or something more systematic?

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