Tim Osborn

🏔️Yakutat Glacier is one of the fastest-retreating glaciers on Earth.

This "before and after" is a stark reminder that glaciers are sensitive indicators of climate change, and around the world, they are retreating due to rising temperatures.

#Glaciers2025

What a beauty... a terrible monstrous beauty... #StormAmy #Humberto from METEOSAT-12/ MTG water vapour 6.2micron channel: The dark area is dry, descending air. Where it forms the scorpion's tail in the final frame (dare I say "sting") is location of some of the most violent winds

Glaciers in California’s Sierra Nevada are likely disappearing for the first time in the Holocene The projected loss of glaciers in California’s Sierra Nevada is likely unprecedented in at least the past 30,000 years.

Very cool work (with a very sobering result) led by Andy Jones (a paleoCAMP alumnus!) in Science Advances: 'Glaciers in California’s Sierra Nevada are likely disappearing for the first time in the Holocene' www.science.org/doi/10.1126/...

The rainfall observers Over the past three centuries, thousands of people across the British and Irish Isles have regularly recorded rainfall, often every day for decades. Their efforts allow us to reconstruct long-term tr...

The Rainfall Observers

Over the past three centuries, thousands of people across the British & Irish Isles have recorded rainfall, often every day for decades. Here we recognise some of the individuals who made particularly important contributions.

rmets.onlinelibrary.wiley.com/doi/10.1002/...

A statement from the President of the Royal Society | Royal Society A statement from the President of the Royal Society regarding threats to the values that allow science to flourish.

"I am increasingly concerned over threats to the values that allow science to flourish." Read the full statement from the President of the Royal Society Sir Adrian Smith: royalsociety.org/news/2025/10...

Just a reminder that NWS is considered essential during a government shutdown. Meteorologists will still go to work, forecasts will still be made, watches and warnings will be issued, data will flow. We won’t be paid until the shutdown ends, but we’ll still protect life and property as always.

Estimates temperature changes from 1400-1960 over the mid to high latitudes of the Northern Hemisphere as a function of longitude covering North America, Europe and Russia. From work by Tim Osborn and colleagues in 2004, based on records of tree-ring maximum latewood density.

Climate stripes by longitude? Here's mine from 2004.

Full Professorship (W3) for Physics of the Oceans - Potsdam-Mittelmark, Brandenburg (DE) job with Universität Potsdam | 12844582 Founded in 1991, the University of Potsdam has firmly established itself in the scientific landscape and has become an outstanding economic factor ...

Here‘s a rare and excellent career opportunity for outstanding physical oceanographers at the Potsdam Institute (PIK) and the University of Potsdam, in beautiful surroundings just outside Berlin. Tell qualified friends or colleagues! 🌊
www.nature.com/naturecareer...

I'm a really big fan of these "storyline" approaches to uncertain forecasts – such a simple way to communicate quite a lot of detail and I think in a way that makes sense to many. Hope to see more of these on TV

Why Norwich continues to be at the heart of climate change research Why Norwich continues to be at the heart of climate change research

To celebrate its 25th anniversary, the Tyndall Centre has just hosted its largest ever climate conference on the UEA campus in Norwich, UK - ‘The Critical Decade for Climate Action':

Pedro Sánchez anuncia que España se adherirá a la Iniciativa Global para la Integridad de la Información sobre Cambio Climático Nueva York, miércoles, 24 de septiembre de 2025. El jefe del Ejecutivo, Pedro Sánchez, ha intervenido en el evento de alto nivel sobre Acción Climática, celebrado en la sala del Consejo de…

Spain has just announced it’s joining the Global Initiative for Information Integrity on Climate Change.

"Disinformation not only creates confusion and spreads fake news; in the context of the climate emergency, it also puts lives and property at risk. Climate misinformation kills"

buff.ly/cixOfB9

Vacancy — PhD Position: "When Lies Take Root: Investigating the Impact of Misinformation on Those at Risk" Are you motivated to protect those most vulnerable against misinformation and to develop new interventions against misinformation? Do you want to know more about how mis- and disinformation impact at-...

If you're looking to do a PhD on a timely subject, I'm on the advisory board of a cool new project; "When Lies Take Root: Investigating the Impact of Misinformation on Those at Risk" at the top-ranked Amsterdam School of Communication Research/

Do share & apply: werkenbij.uva.nl/en/vacancies...

Seasonal and interannual variability in freshwater sources for Greenland's fjords Abstract. The magnitude, source, release location, and timing of freshwater that ends up in the numerous Greenland fjords is of special interest for ice–ocean interactions and ecosystems. In this stud...

Last week I published my first PhD paper on the sources of freshwater for Greenland's fjords (tc.copernicus.org/articles/19/...)

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...

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.

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

Thanks for the comment. Decision to use USHCN as a source predated my involvement and very likely made sense at the time, fitting with the CRUTEM approach. But, yes, it’s on the to-do list to move to a better option for the US data

Record temperatures linked to human-caused climate change New research by climate scientists at Maynooth University in conjunction with Met Éireann has found Ireland's record summer night time temperatures this year were made 40 times more likely by human-ca...

Great to see coverage of our first full @wasitusie.bsky.social study on RTE (and elsewhere). Kudos @clairebergin.bsky.social and Lionel swan as well as met Éireann colleagues and thanks as ever to @wwattribution.bsky.social for the hugely valuable collaboration www.rte.ie/news/ireland...

Beautiful thread about the function of terpenes for trees!

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!

The people I work with are not stupid people and our climate predictions of 30 years ago of global warming have proved to be accurate. Just saying. www.bbc.co.uk/news/live/cp...

Hours of daylight throughout the year in the Northern Hemisphere.

There is a US-specific issue for the current year to be aware of: bsky.app/profile/timo...

This doesn't mean that the US data are not available, just that they aren't in the specific data feed that CRUTEM/HadCRUT uses. Other global temperature datasets probably get them via other data feeds.

For regular monthly updates to CRUTEM (and hence to HadCRUT) we rely on monthly data provided by National Met Services via the WMO's CLIMAT system. Unusually, the USA data didn't yet make it into the CLIMAT data feed for Mar-Jun 2025. Note the USA-sized gap in the non-infilled version of HadCRUT:

Not sure about the US changes, though the different time series doesn't show such prominent changes as for China, so there must be some cancelling of +ve and -ve changes even though the difference map looks a bit blue overall in that region

A Third Generation of Homogenized Temperature for Trend Analysis and Monitoring Changes in Canada’s Climate This study presents the development of a new dataset of homogenized temperature for use in trend analysis and monitoring climate change in Canada. This dataset contains daily data for 780 locations...

I'd have to ask my colleague David Lister as he did the N American station database updates. For Canada, it may be related to us now using the 3rd gen of their homogenised temperatures data -- improved homogeneity and more stations doi.org/10.1080/0705...

PDF version is here crudata.uea.ac.uk/~timo/diag/t...

Thanks! If you zoom in on the PDF version you can see how I drew the different levels of shading 👇

And some visualisations are available here:
crudata.uea.ac.uk/~timo/diag/t...
including 12-month running means of global land+marine (HadCRUT) and global land (CRUTEM) temperature anomalies

As usual data are available from the CRU website:
crudata.uea.ac.uk/cru/data/tem...

and the Met Office website:
www.metoffice.gov.uk/hadobs/index...

You can see the effect of this China data update in the map of the difference between CRUTEM.5.1.0.0 and CRUTEM.5.0.2.0 averaged over 2019-2023 (previous post) and for the same period in the difference time series for Asia from here: www.metoffice.gov.uk/hadobs/crute...