John J. Cullen

John J. Cullen

@johncullenocean.bsky.social

Professor Emeritus in Oceanography, Dalhousie University. 🇨🇦🧪🌊 I've spent a long time trying to understand and explain how the ocean works.

4K followers57 following24 posts

John J. Cullen reposted

I'm afraid that this is why the US administration wants to shut down ocean observations: they don't want the people to know what is happening in our oceans, as it does not fit their ideology and the interests of their fossil fuel industry funders. edition.cnn.com/2026/06/03/c...

edition.cnn.comThe oceans are in deep trouble. The Trump administration just ditched a vital deep-sea monitoring system | CNNThe Trump administration will dismantle a $368 million monitoring system that provides critical data on the world’s oceans, sparking alarm among scientists

Someone who doesn't know much about oceanography asked me if the dismantling of ocean monitoring capabilities was stupid and/or evil. It is stupid AND evil. The War on Science continues. As more people see it and push back, maybe the tide can be turned. 🌊🧪 www.theguardian.com/environment/...

theguardian.comDismay as Trump officials to dismantle key ocean monitoring systemOcean Observatories Initiative, $368m network that has provided crucial climate data, latest victim of Trump cuts

Reposting this because I forgot 🌊 and 🧪. My point is that it is bedrock scientific fact that marine biomass for consumption is not CDR, so studies making that particular assumption should not pass peer review or due diligence. Thanks to @jaytcullen.bsky.social for the reminder.

John J. Cullen@johncullenocean.bsky.social

A fundamental fact should have stopped the original publication in its tracks: The organic carbon in oyster biomass is not mCDR. We eat it, use it, and exhale most of it as CO2. That's what animals do — organic carbon in, carbon dioxide out. What we don't use goes to sewage —> greenhouse gases.

A fundamental fact should have stopped the original publication in its tracks: The organic carbon in oyster biomass is not mCDR. We eat it, use it, and exhale most of it as CO2. That's what animals do — organic carbon in, carbon dioxide out. What we don't use goes to sewage —> greenhouse gases.

linkedin.comScientific evidence does not support oyster farming as a marine carbon dioxide removal strategy for climate mitigation | PNAS | John CullenGentle people: The challenges in PNAS to a seriously flawed study of oyster farming for carbon dioxide removal are completely valid. The reply by the study's authors does not address core issues. To...
Jean-Pierre Gattuso@jpgattuso.bsky.social

1/x ‼️ Check out our letter to @pnas.org, led by Fabrice Pernet, which discusses a paper claiming "Oyster farming acts as a marine carbon dioxide removal (mCDR) hotspot for climate change mitigation." 🌊 doi.org/10.1073/pnas...

John J. Cullen reposted

Replying to @katharinehayhoe.com

As James says, this isn't even about climate. It's about all the tools, platforms, models, datasets we use to study and forecast weather and understand how it impacts people, too.

James Franklin@franklinjamesl.bsky.social

These people are nuts. NCAR developed the GPS dropsonde, which revolutionized the understanding of TC structure, improved forecasts, and validated remote sensing platforms, as documented in over 400 peer-reviewed publications in the last 25 years. And that’s just one of NCAR’s countless advances.

John J. Cullen reposted

Replying to @scottdoney.bsky.social

Dismantling NCAR @ncar-ucar.bsky.social is a bad decision for many reasons. NSF’s investment in NCAR scientists, technical staff, facilities and research products supports and catalyzes atmosphere, ocean, and Earth system science across the nation and world with a substantial ROI.

🌊 Post from Jay Cullen took me to the PNAS article on oyster farming as mCDR. Seems that farmed oyster biomass is counted as sequestered carbon for climate change mitigation. No mention of what happens to oyster carbon after we eat it. Maybe I read it wrong. www.pnas.org/doi/10.1073/...

pnas.orgPNASProceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans...
Jay T. Cullen@jaytcullen.bsky.social

🌊 Interesting that a heterotrophic organism that precipitates CaCO3 could be a carbon sink

If due-diligence of mCDR investors included solid engagement with expert ocean scientists like Hurd and others – who have years of experience and publish peer-reviewed research – the cycle of hype and waste might be replaced with a better path to solutions. 🌊 www.canarymedia.com/articles/car...

canarymedia.comUnder the sea: Running Tide’s ill-fated adventure in ocean carbon…The startup made a big splash, then ran aground this summer. Its story has a lot to teach us about trying to geoengineer our way out of climate change.
David Ho@davidho.bsky.social

Catriona Hurd gave a great talk at #LiegeOcean25 showing why ocean afforestation with seaweed for CO₂ removal (CDR) is bullshit.

The arguments about uncertain global effects and limited efficacy have been supported by others for years. One more thing: if harmful blooms or hypoxic fish kills happen anywhere that is influenced by OIF, legal fingers will point, deservedly or not. Who will underwrite liability insurance? 🌊

David Ho@davidho.bsky.social

Maybe this @johncullenocean.bsky.social et al. piece where they said — "adding iron to the ocean is not an effective way to fight climate change, and we don't need further research to establish that" — wasn't straightforward enough because this idea just won't die. 🤷🏻‍♂️ www.nature.com/articles/461...

John J. Cullen reposted

The US does not stand for freedom and democracy any more, but is sliding fast into tyranny. Harvard is punished for standing up to this. If you’re in the US and not doing something now, soon you will be unable to do anything. We know this from experience here in Germany.

This post is unavailable.

John J. Cullen reposted

👿 NSF in Turmoil: Radical Reorganization, Removal of Directors, Forced Layoffs 🧪 Follows take over by DOGE #SaveNSF science.org

Dr. David Miller 🏳️‍🌈@davidimiller.bsky.social

🚨 Breaking: NSF faces radical shake-up as officials abolish its 37 divisions 1️⃣ Removes/demotes division director leaders 2️⃣ Forced layoff notices to NSF staff going out tonight 3️⃣ More grant terminations expected tomorrow One glimmer of hope: the 8 directorates appear to be staying

John J. Cullen reposted

🔔BREAKING🔔 The NSF has frozen all research grant awards—cutting off life-saving science midstream and demanding ideological screenings for future funding. This is censorship disguised as oversight. Here’s how you can help us spread the word ➡️🧵(1/3): www.nature.com/articles/d41...

nature.comExclusive: NSF stops awarding new grants and funding existing onesUS science funder also plans to screen grant applications for compliance with ‘agency priorities’.

John J. Cullen reposted

Replying to @davidho.bsky.social

I was in the process of hiring a postdoc, so this severely affects her career because now she has to look for something else. It also means I can't pay my existing people, can't buy supplies for the lab, and can't travel. Every NSF-funded researcher will be in the same boat soon.

Delighted to see that Scott Doney has been honored with election to the NAS. His research represents truly interdisciplinary oceanography at its best, he has been a standout in public service, and (dare we say this about scientists?) he is a model of generosity and kindness. Congrats, Scott! 🌊🧪

Scott Doney@scottdoney.bsky.social

Huge thanks to the many teachers, mentors, colleagues, postdocs & students who have supported my science career #UVA @usocb.bsky.social @whoi.edu @ncar-ucar.bsky.social @ucsandiego.bsky.social @sea1971.bsky.social @nasagoddard.bsky.social www.nasonline.org/news/2025-na...

John J. Cullen reposted

Replying to @altnps.bsky.social

The Act prohibits actions that “harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect” endangered species. Right now, “harm” includes damage to a species’ habitat—but the Trump administration is attempting to strip habitat destruction from that definition.

John J. Cullen reposted

This administration continues to outdo itself by doing really really dumb things. Princeton has one of the best climate modeling groups in the world, and this administration just cut their funding justified with some anti-science bs.

commerce.govEnding Cooperative Agreements’ Funding to Princeton UniversityOn Tuesday, April 8, 2025, U.S. Secretary of Commerce Howard Lutnick announced that nearly $4 million in funding is ending to Princeton University after a detailed, careful, and thorough review of the...

John J. Cullen reposted

John J. Cullen reposted

As we watch Trump's attack on universities, remember that Poilievre promises to appoint a "Free Speech Guardian" for universities. A university could lose its federal funding if this politically appointed "guardian" recommends it.

John J. Cullen reposted

This is bananas. 'Canadian researchers are asked to confirm that their research: - does not include a climate or “environmental justice” component - does not contain diversity, equity and inclusion (DEI) elements - does not ascribe to “gender ideology' 🧪 🌎 www.globenewswire.com/news-release...

globenewswire.comTrump administration threatening Canadian researchersOTTAWA, Ontario, March 18, 2025 (GLOBE NEWSWIRE) -- The Canadian Association of University Teachers (CAUT) is warning that the Trump administration is...

John J. Cullen reposted

If this looks old it's because it's been up there a while.

David Ho@davidho.bsky.social

If we don't stand up for science, we'll fall for bullshit that threats our ability to secure a livable future for everyone.

John J. Cullen reposted

This is fascinating. Give it a read!

Craig Baird-Canadian History Ehx@cdnhistoryehx.bsky.social

In 1890, the Tariff Act came into place in the United States. It placed tariffs on imports of up to 50%. While touted as a way to build American industry, there was also the hope it would force an annexation of Canada. It backfired. Let's learn more. 🧵1/10

Tommy Dickey (1945-2025). When he started out, oceanography was pursued in disciplinary silos, bio-optical oceanography did not exist, and robotic observation of global ocean biogeochemistry was not yet a dream. Tommy was central in getting us where we are today.🌊 www.geog.ucsb.edu/people/facul...

geog.ucsb.eduTommy Dickey | Department of Geography | UC Santa BarbaraInterdisciplinary ocean research topics have included: bio-optics, biogeochemistry, hurricanes, ocean eddies, and monsoons plus medical research concerning the use of scent detection dogs for COVID-19...

First Ocean Sciences Meeting outside the US is a big deal. As a bonus, no state-sponsored suppression of climate science. Neaps and tatties, too! May the force be with you, @aslo.org, @tosoceanography.bsky.social, @agu.org. 🌊🧪

Save the date! The Ocean Sciences Meeting is coming to Glasgow, Scotland, 22-27 Feb 2026—the first OSM outside the US! 🌍 Join scientists, students, journalists, & more to grow our global ocean community, foster partnerships & build a sustainable future. #OSM26 @agu.org @tosoceanography.bsky.social

John J. Cullen reposted

Non-scientists need to understand the current war on science and how it's being waged and whitewashed. Canada suffered such a putsch in the Harper era, when ConBot ideologues removed gov't #climate pages, shuttered StatsCan, threw books/data in a dumpster, and had oil criminals rewrite enviro laws.

The Alchemy of Air by Thomas Hager is a first-rate story of science, technology, society, and survivability of the human race. The lessons about what happened when big institutions (including universities) appeased the regime to stay in good favor are ominously relevant.

David Ho@davidho.bsky.social

I knew that Haber-Bosch uses 1% of the world’s energy to produces fixed nitrogen needed for food production, without which 2-3 billion people would starve to death. But I didn’t know the whole story. Thanks to @pauldauenhauer.bsky.social for the book recommendation.

Mary Somerville was born on 26 December 1780. Among her many accomplishments, she described foundational principles of ocean optics – including the influence of phytoplankton on ocean color. The 20th century pioneers of ocean-color remote sensing were unaware. She was far ahead of her time. 🌊🧪

Frenger et al. (doi/10.1111/gcb.17124) remind us that export flux of organic C by the biological pump cannot be equated to the flux of atmospheric CO2 to the ocean. We must account for upward transport of DIC, including DIC:N:P in vertically transported nutrients. Read quote from classic 1979 paper.

Andreas Oschlies@aoschlies.bsky.social

Eye-opening discussion regarding the (small!) role of the marine biological carbon pump in contemporary changes in the global carbon cycle, carefully drafted by excellent lead authors Ivy Frenger and Angela Landolfi. lnkd.in/dX9RN6qZ

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