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James Rae

@mudwaterclimate.bsky.social
2K followers 631 following 102 posts

Climate scientist and geochemist @UnivofStAndrews | CO2 & ocean circulation past & present | Social & Environmental justice

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James Rae @mudwaterclimate.bsky.social · 28/05/2026
What’s the German word for the opposite of a dunkelflaute?! Sunny and windy conditions in the U.K. currently pushing down fossil gas generation to only 6.5% on UK electricity grid grid.iamkate.com 🔌⚡️🌬️☀️
Pie chart of the sources of electricity generation on the U.K. grid. Large segments of yellow (solar) and green (wind) reflecting sunny, windy conditions. Fossil gas is a small orange segment.
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James Rae @mudwaterclimate.bsky.social · 07/05/2026
Was a real pleasure speaking to @elisecutts.bsky.social for Science on the beautiful new CO2 results over the MPT from Beyond EPICA presented by Florian Krauss at EGU. (And also nice to see them line up nicely with our CO2 reconstruction from boron!)
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James Rae @mudwaterclimate.bsky.social · 20/03/2026
Final call for our opening in @earthscista.bsky.social - chair in Earth Sciences, closes Monday. Fancy escaping to a great University in a lovely wee country? Need a wee weekend project?! Then get your applications in! 🧪⚒️🌊
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James Rae @mudwaterclimate.bsky.social · 14/03/2026
Thanks Gaurav! Should all be there in the paper supplement and also on our GitHub github.com/St-Andrews-I...
github.com
Release Atmospheric CO2 over the Past 66 Million Years from Marine Archives · St-Andrews-Isotope-Geochemistry/Publications
Code and files associated with: James W.B. Rae, Yi Ge Zhang, Xiaoqing Liu, Gavin L. Foster, Heather M. Stoll, Ross D.M. Whiteford, 2021, Atmospheric CO2 over the Past 66 Million Years from Marine A...
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James Rae @mudwaterclimate.bsky.social · 14/03/2026
Chair in Earth Sciences position @uniofstandrews.bsky.social closing soon - Monday 23 March. Very broad remit, so if you’d like to join our lovely school, and get to live in the super beautiful and friendly wee nation of Scotland, please apply! www.st-andrews.ac.uk/earth-scienc... ⚒️🌊🧪
East Sands beach, St Andrews, in the sunshine (which happens more often than you probably think!)
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David Ho @davidho.bsky.social · 24/02/2026
@mudwaterclimate.bsky.social is a professor in the School of Earth and Environmental Sciences at @uniofstandrews.bsky.social. His research focuses on geochemical measurements to reconstruct past changes in climate to understand their causes so we can better predict changes in the future.
A close-up, black and white portrait of a smiling man with a shaved head, positioned outdoors against a softly blurred background. He's wearing a dark, collared button-down shirt. The background features the out-of-focus silhouette of a large industrial structure, the Finnieston Crane, under an overcast sky.
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James Rae @mudwaterclimate.bsky.social · 25/02/2026
Absolutely! Somehow he managed to avoid capturing my big overly mobile face in one of its usually silly expressions and get to what I think I might actually look like! Thanks @davidho.bsky.social!
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Will Gray @willerstorfi.bsky.social · 04/12/2025
new paper led by Andressa Nauter-Alves assessing controls on trace elements (Mg, Sr, B, Li /Ca) in multiple species of benthic foraminifera using a large compilation of coretop samples (>1500 sites). dx.doi.org/10.1029/2025...
dx.doi.org
Thermal and Non‐Thermal Controls on Benthic Foraminiferal Mg/Ca, Sr/Ca, B/Ca, and Mg/Li: Global Core‐Top Compilation, Revised Calibrations, and Application to the Geologic Record
We compile ∼1,500 core-top benthic foraminiferal Mg-Sr-B-Li/Ca measurements from five species and one genus to produce new calibrations Many benthic foraminiferal elemental systems require multiv...
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Katharine Hayhoe @katharinehayhoe.com · 22/11/2025
"Despite the difficulties getting everyone to agree on how to tackle climate change, real-world solutions are being implemented at speed almost everywhere." Love this #COP30 takeaway from @georginarannard.bsky.social. Just because countries aren't acting at scale doesn't mean the rest of us can't!
bbc.com
COP30 in Brazil fails to secure new pledges to cut fossil fuels - follow live
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Chris Baraniuk @chrisbaraniuk.com · 13/11/2025
NEW: I wrote about British churches installing heat pumps, in some cases in 1,000-year-old buildings! Decarbonisation may not be easy, but many view it as an act of faith. This is a special feature to mark The Reengineer’s first anniversary! Spread the word! 🥳 www.thereengineer.pro/p/let-there-...
thereengineer.pro
Let there be warmth! The British churches putting their faith in heat pumps
Ancient buildings and old bones aren’t getting in the way of decarbonisation
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James Rae @mudwaterclimate.bsky.social · 13/11/2025
In the case of coastal upwelling zones, yes! In the offshore gyres acidification tracks the atmosphere, but this water is then subducted & gets additional carbon from remineralisation, pushing it into CO2 chemistry space where the acidification from that initial CO2 uptake is amplified
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James Rae @mudwaterclimate.bsky.social · 13/11/2025
🚨Out today, acidification of the California Current🚨 Using corals and models we show regionally amplified acidification, due to the combo of CO2 uptake and remineralisation. This highlights potential risks to productive upwelling zones in an acidifying ocean 🌊🧪⚒️📈 www.nature.com/articles/s41...
Fossil coral boron isotope data used to reconstruct California Current pCO2.  In a non-acidifying ocean, the data should fall on the grey 1:1 line.  Instead they fall below, indicating an acidifying ocean, and show greater acidification at greater depths (symbol colour), consistent with model simulations (dashed lines) - a phenomenon explained on the next figure! Upwelling zones, like the California Current System, experience amplified ocean acidification, as the anthropogenic CO2 taken up in the offshore waters  - which then get subducted and go on to feed the upwelling zone - is added to by carbon from remineralisation.  This means that the upwelling waters end up in a much more carbon-rich part of total alkalinity (TA) versus dissolved inorganic carbon (DIC) space, where CO2 (and pH) contours are much closer together.  The result is that 100 ppm carbon uptake offshore results in a nearshore pCO2 change of 300 ppm.
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James Rae @mudwaterclimate.bsky.social · 03/10/2025
Sure! And great work @jfarmersalmanac.bsky.social and @oceanandclimate.bsky.social for the fascinating paper and threads!
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James Rae @mudwaterclimate.bsky.social · 17/09/2025
Kudos to Maddie for leading this work and many thanks to @willerstorfi.bsky.social @gmacgilchrist.bsky.social @oceanicandrea.bsky.social Casimir de Lavergne & Laurie Menviel for all their help and input, @uniofstandrews.bsky.social for funding Maddie’s PhD, and all of you for reading!
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James Rae @mudwaterclimate.bsky.social · 17/09/2025
We are psyched about this as the ice ages are cool (sorry!) - but also as figuring out these processes by which the ocean took up 100s of gigatonnes of CO2 from the atmosphere in the past may help us better understand the controls on its capacity for carbon uptake in the future… 📈🌊
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James Rae @mudwaterclimate.bsky.social · 17/09/2025
This likely acted in concert with other processes (changes in winds, circulation, sea ice, iron) to draw down CO2 during the ice ages. It can also explain why biogeochemical records from the North Pacific and Southern Ocean share similar structure (Haug & Sigman‘s “polar twins” 👯)
Reconstructions of biogeochemistry from the high latitude North Pacific and Southern Oceans share similar structure over the ice ages
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James Rae @mudwaterclimate.bsky.social · 17/09/2025
Notably, this is achieved without any change in Southern Ocean upwelling, sea ice or iron supply - it’s simply the result of having less carbon in the upwelled water.
Potential CO2 outgassing anomalies in 4 different sets of model simulations with better ventilated intermediate depth North Pacific
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James Rae @mudwaterclimate.bsky.social · 17/09/2025
The consequence - shown here - is that less CO2 would be delivered to the Southern Ocean. This by itself reduces Southern Ocean CO2 outgassing by as much as 50%.
Outgassing anomaly in the Southern Ocean - less carbon is outgassed due to reduced carbon load of waters upwelled from the Pacific
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James Rae @mudwaterclimate.bsky.social · 17/09/2025
In previous papers we and others have shown that these intermediate depth N Pacific waters were better ventilated during glacial periods (e.g. figure here from Rae 2020 and see also Rafter 2022 and Keigwin 1998 among others!) www.science.org/doi/full/10....
Figure showing change in different proxies sensitive to ventilation at the LGM relative to today in the North Pacific. Better ventilation is shown by the red dots - and there is a clear signal of this above 2000m.
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James Rae @mudwaterclimate.bsky.social · 17/09/2025
Part of the inspiration for this study was an interesting paper by Haidi Chen showing that much of the CO2 outgassed in the Southern Ocean today is sourced from the intermediate depth North Pacific. As these waters are old and CO2 rich they have huge outgassing potential (red colours below).
Figure showing ocean outgassing potential - the tendency of a parcel of water to give out CO2 to the atmosphere when it surfaces. Red colours in the North Pacific show its high outgassing potential and these isopycnals outcrop in the Southern Ocean, fuelling regional outgassing.
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James Rae @mudwaterclimate.bsky.social · 17/09/2025
🚨New paper on Southern Ocean CO2🚨 Using a suite of Earth system models, Maddie Shankle et al show that better ventilation of intermediate waters in the North Pacific ends up reducing outgassing of CO2 in the Southern Ocean 🌊🧪⚒️🧵 @earthscista.bsky.social www.nature.com/articles/s41...
nature.com
Southern Ocean CO2 outgassing and nutrient load reduced by a well-ventilated glacial North Pacific - Nature Communications
A better-ventilated North Pacific could have reduced the carbon of water upwelled in the Southern Ocean, reducing outgassing and revealing a remote influence on Southern Ocean biogeochemistry in glaci...
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St Andrews Earth & Environmental Sciences @earthscista.bsky.social · 06/09/2025
Big congratulations to @mudwaterclimate.bsky.social & team on securing funding to launch the St Andrews Global Research Centre for Changing Climates! 🌍 📈 The centre will take an interdisciplinary approach, harnessing the breadth of expertise across St Andrews news.st-andrews.ac.uk/archive/the-...
news.st-andrews.ac.uk
The University of St Andrews announces two new Global Research Centres | University of St Andrews news
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James Rae @mudwaterclimate.bsky.social · 04/08/2025
Nice one John - see also additional notes in thread below: bsky.app/profile/mudw...
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Damian Carrington @dpcarrington.bsky.social · 04/08/2025
ICYM - Scientists slam Trump administration climate report as a ‘farce’ full of misinformation - Experts say the report being used to justify the mass rollback of climate regulations has many claims based on long-debunked research #climatecrisis www.theguardian.com/us-news/2025...
theguardian.com
Scientists slam Trump administration climate report as a ‘farce’ full of misinformation
Experts say the report being used to justify the mass rollback of climate regulations has many claims based on long-debunked research
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James Rae @mudwaterclimate.bsky.social · 04/08/2025
More relevant for fossil fuel CO2 are rapid external carbon additions from large igneous provinces and the organic material they often burn up - consistently linked to mass extinction in the geological record www.nature.com/articles/s41...
Graph showing extinction rate over the past 300 million years and current pH reconstructions. Mass extinctions are consistently associated with ocean acidification.
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James Rae @mudwaterclimate.bsky.social · 04/08/2025
These sorts of relatively slow reshufflings of carbon around the ocean also aren’t a relevant analogue for very rapid addition of carbon from an external source: in former case saturation state changes are muted, while with FF addition saturation state drops sharply www.science.org/doi/10.1126/...
science.org
The Geological Record of Ocean Acidification
As human activity continues to pump nearly 50-fold more CO2 into the atmosphere than any existing natural sources, the oceans absorb it. Over time, this vast quantity of excess oceanic CO2 is expected...
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James Rae @mudwaterclimate.bsky.social · 04/08/2025
It’s a pretty basic misrepresentation- they use our paper to suggest ice age ocean was more acidic, but we show this was only true for deep Southern Ocean, while upper ocean (much more relevant for OA-sensitive ecosystems) had higher pH! www.nature.com/articles/s41...
nature.com
CO2 storage and release in the deep Southern Ocean on millennial to centennial timescales - Nature
Analysis of deep-sea coral boron isotope data, as a proxy for pH and thus CO2 chemistry, provides evidence of CO2 storage in the deep Southern Ocean during the last ice age, and its rapid release on m...
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Andrew Dessler @andrewdessler.com · 31/07/2025
🚨 If you're interested in working on a coordinated response to the DOE climate report, please enter your info on this google form 🚨 Please RT this so as many people see it as possible. forms.gle/BL9xUAfRxA...
forms.gle
DOE climate report response form
We are collecting names to assemble a writing team to respond to the DOE climate working group report. If you'd like to contribute, enter your info below. At this point, there is no guarantee what we'll do (if anything), but we want to keep our options open by collecting names. If you have any further questions, feel free to email me. We are primarily looking for Ph.D. scientists at universities or government labs in appropriate fields. I realize that this will exclude some qualified people and I apologize, but we felt this was necessary for a variety of reasons.
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Anna Kramer @annackramer.bsky.social · 31/07/2025
🚨 At least 10 scientists, all cited in the Trump admin's new climate change report, told me that the report completely mischaracterizes their research. I also found five citations with significant errors, and a paragraph missing an important citation.
notus.org
‘A Serious Misuse of My Research’: Climate Scientists Say New Trump Energy Report Botches Their Work
“Our work has no relevance,” an astrobiologist whose research was cited in the administration’s climate change report said.
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Robert Rohde @rarohde.bsky.social · 31/07/2025
I've been taking some time to dive into the US EPA's Proposal to revoke the Endangerment Finding related to Greenhouse Gases. epa.gov/system/files... They put forth multiple lines of argument about why the current administration believes this should happen. 🧵
epa.gov
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James Rae @mudwaterclimate.bsky.social · 30/07/2025
Add me to the list! Rae 2018 misrepresented on page 7: we show deep ocean pH rose out of the ice - but surface ocean pH (the more relevant property for the vast majority of marine life) fell! Please see thread below on catastrophic impact of geological pH change: bsky.app/profile/mudw...
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David Ho @davidho.bsky.social · 30/07/2025
Motherfucking wind farms…
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Howard Lee @hlee.bsky.social · 15/07/2025
Fascinating paper 👇 not only providing evidence for ocean acidification in the end-Triassic mass extinction, but also wider discussion of the role of reverse weathering in prolonging the effects, and how this changed with the evolution of open ocean calcifying organisms. ⚒️🧪
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James Rae @mudwaterclimate.bsky.social · 15/07/2025
Finally for anyone needing a boost on climate progress in light of record temperatures and an acidifying ocean, please check out this wonderful article by @billmckibben.bsky.social - the challenge is huge, but so is our progress www.newyorker.com/news/annals-... 🧪💡🔌⚡️☀️
newyorker.com
4.6 Billion Years On, the Sun Is Having a Moment
In the past two years, without much notice, solar power has begun to truly transform the world’s energy system.
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James Rae @mudwaterclimate.bsky.social · 15/07/2025
Not dumb at all - today the open ocean has lots of tiny planktonic carbonate shells that coat the seafloor when they die. This acts as an anti-acid: CO2 addition is part neutralised by dissolving those shells. But they weren’t around yet in the Triassic/Jurassic.
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James Rae @mudwaterclimate.bsky.social · 15/07/2025
HUGE kudos to fantastic former @earthscista.bsky.social PhD student @mollytrudgill.bsky.social for leading this work, @carbonatefan.bsky.social for ushering us in to the rock record and being generally the best, and an amazing team including several @uniofstandrews.bsky.social BSc/MSc co-authors
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James Rae @mudwaterclimate.bsky.social · 15/07/2025
These data demonstrate that ocean acidification is associated with all of the major mass extinctions where we currently have pH reconstructions. The TJ pH drop is similar to possible scenarios in 2100 unless fossil fuel emissions are rapidly reduced. 🐚🌊📉.
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James Rae @mudwaterclimate.bsky.social · 15/07/2025
Faster carbon input at the extinction (indicated by its more rapid carbon isotope excursion) would have led to more pronounced acidification impacts, in particular due to the lack of a deep sea carbonate buffer (read oceanic anti-acid) - indeed this may partly explain this era's major extinctions
 Modelled saturation state decline. Saturation state decline modelled in cGENIE for different carbon sources and different sizes of negative carbon isotope excursion for runs with a75 kyr onset duration. With the same carbon source as the main CIE (>−12‰), we interpolate an emission rate of >500 GtC/kyr associated with the initial CIE (~5‰) and thus a >6 drop in calcite saturation state in an ocean without pelagic calcifiers.
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James Rae @mudwaterclimate.bsky.social · 15/07/2025
Our new boron data cover the "Main" carbon isotope excursion, just after the end-Triassic extinction event. Comparing the carbon and boron isotopes allows us to fingerprint a volcanic carbon source from the Central Atlantic Magmatic Province as the Atlantic opened up.
Oxygen, carbon, and boron isotope data, showing warming, carbon input, and acidification
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James Rae @mudwaterclimate.bsky.social · 15/07/2025
🚨New paper just out on environmental upset at the Triassic-Jurassic boundary🚨 Using boron isotopes in fossil oysters, we find a major pulse of ocean acidification and CO2 rise, driving global warming and delaying ecosystem recovery following the end-Triassic mass extinction rdcu.be/ev6XV 🧪🌊⚒️🐚🧵
Journal title in Nature Communications
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James Rae @mudwaterclimate.bsky.social · 06/01/2025
This work helps better constrain a good chunk of the geological history of CO2 - but plenty more time intervals to come!
A graph showing atmospheric CO2 reconstructions over the Palaeozoic, between around 500 and 250 million years ago. Our new data show low CO2 between 340 and 295 Ma, followed by rapid CO2 rise at the start of the Permian
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James Rae @mudwaterclimate.bsky.social · 06/01/2025
Kudos to @uniofstandrews.bsky.social research fellow Hana Jurikova for leading this massive collaborative project, Ross Whiteford for developing novel calculation methods, and brilliant collaborators who contributed all sorts of samples and expertise - plus amazing geological artwork
Palaeo-artistic rendering based on findings of this study and previously published literature. A relatively rapid rise in atmospheric CO2 approximately 294 Ma released the Earth from its penultimate icehouse (left) and transitioned the world to a warmer and drier climate of the Early Permian (right).
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James Rae @mudwaterclimate.bsky.social · 06/01/2025
Super excited to share our latest on CO2’s role in geological climate change! Using boron isotopes in ~300 million year old brachiopod shells, we show that rising CO2 from volcanic emissions drove a profound change in climate that ended the Late Palaeozoic Ice Age ⚒️🧪🌊 www.nature.com/articles/s41...
nature.com
Rapid rise in atmospheric CO2 marked the end of the Late Palaeozoic Ice Age - Nature Geoscience
A pronounced increase in atmospheric CO2 coincided with warming at the end of the Late Palaeozoic Ice Age, according to an 80-million-year-long boron isotope CO2 proxy record.
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ECIU @eciu.net · 12/12/2024
England has second worst harvest on record with fears mounting for 2025 Data released shows England experienced it’s second worst harvest since 1983 after record breaking wet weather last winter, with recent downpours leaving many farmers unable to drill crops again.
buff.ly
Confirmed: England has second worst harvest on record with fears…
Data released shows England experienced it’s second worst harvest since 1983 after record breaking wet weather last winter, with recent downpours leaving many farmers unable to drill crops again
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James Rae @mudwaterclimate.bsky.social · 12/12/2024
Nice thing about an 0830 sunrise is it’s easier to enjoy! Absolute beauty in St Andrews this morning.
A pretty sunrise with the spires of St Andrews visible in the background
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James Rae @mudwaterclimate.bsky.social · 03/12/2024
Today my amazing colleague, lab mate, and partner @oceanicandrea.bsky.social officially became the first female Professor of Earth and Environmental Sciences @uniofstandrews.bsky.social. Let’s make sure it doesn’t take another 611 years to get the next ⚒️🧪🌊👩🏻‍🔬
Andrea Burke stands outside a University building at St Andrews in some epic grey and red academic robes with a fun wee hat on top!
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David Ho @davidho.bsky.social · 29/11/2024
We all think plastic pollution is a problem, and it is. In the nearly 70 years between 1950 and 2019, the world produced a total of ~9.5 billion tonnes of plastic. But all the plastic we have EVER produced weighs as much as CO₂ we emitted into the atmosphere during the first three months of 2024!
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James Rae @mudwaterclimate.bsky.social · 25/11/2024
Yeah great point! Didn’t quite get there but great to see a solid 20 GW for the last couple days (e.g. green line below). Also amazing how even at this time of year and latitude solar (yellow) can take a decent bite out of gas (orange) during the day. ☀️💨⚡️ grid.iamkate.com
UK electricity generation over the last 24 hours. Wind has provided a pretty steady 20 GW. Gas ramped up in the morning and evening but went back down during the middle of the day due to solar supply.
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James Rae @mudwaterclimate.bsky.social · 23/11/2024
Yes! Has grown by a couple of GW and lots more in the pipeline too - though need even more to meet renewables and climate targets. en.m.wikipedia.org/wiki/Wind_po...
en.m.wikipedia.org
Wind power in the United Kingdom - Wikipedia
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James Rae @mudwaterclimate.bsky.social · 23/11/2024
Wind generation now at 21.78 GW Record is 21.81 GW sustained over 30 mins last December, so getting close! Can check individual wind farms at excellent GB Renewables map below 💨⚡️🔌🧪⚒️ renewables-map.robinhawkes.com#4.25/54.2/-1...
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