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Lennart Bach @bachlennart.bsky.social · 3d

Interesting study by colleagues in Portugal.

Evaluating ocean alkalinity enhancement for carbon dioxide removal: evidence from a one-year saltmarsh field experiment
🌊

egusphere.copernicus.org/preprints/20...

Evaluating ocean alkalinity enhancement for carbon dioxide removal: evidence from a one-year saltmarsh field experiment

Abstract. Ocean alkalinity enhancement is a promising carbon dioxide removal (CDR) strategy aimed at reducing atmospheric carbon dioxide (CO2) concentrations. To evaluate its effectiveness and potenti...

egusphere.copernicus.org

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Reposted by Lennart Bach

Patrick Rafter @oceanandclimate.bsky.social · 6d

Today, we published a study long in the making on how upper and subsurface tropical Pacific waters responded (and maybe will adjust) to warmer global climate. Here’s the story of how we got here after 15 years. many authors but shout out @jfarmersalmanac.bsky.social
🌊
www.science.org/doi/10.1126/...

Persistent eastern equatorial Pacific Ocean upwelling since the warm Pliocene

Upwelling generates a nutrient-rich “cold tongue” in the eastern equatorial Pacific Ocean (EEP), with impacts on global climate, oceanic biological productivity, and the carbon cycle. The cold tongue ...

www.science.org

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Reposted by Lennart Bach

Olivier Sulpis @sulpis.bsky.social · 9d

🌟 Postdoc Opportunity in Marine Biogeochemistry at CNRS-CEREGE!

🚢 Are you a passionate researcher ready to tackle climate change? Dive into the ERC-funded Deep-C project in Aix-en-Provence, France!

⬇️

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Reposted by Lennart Bach

Dr. Jessica N. Cross @jessicancross.bsky.social · 12d

New mCDR papers this month:

www.frontiersin.org/journals/cli...

www.frontiersin.org/journals/env...

Frontiers | Regional ocean biogeochemical modeling challenges for predicting the effectiveness of marine carbon dioxide removal

Effectively scaling diverse marine carbon dioxide removal (mCDR) technologies from pilot-scale demonstrations to industrial-scale deployments requires a quan...

www.frontiersin.org

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Lennart Bach @bachlennart.bsky.social · 20d

Thanks again to @aaronferderer.bsky.social for going through this massive effort. I think this dataset is a noticeable step forward when it comes to mechanistically understanding phytoplankton responses to carbonate chemistry. More of that in the future!
Well done mate 🍻

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Lennart Bach @bachlennart.bsky.social · 20d

7/n

To explore the data yourself use the tool below. Hopefully, journals find a way to include such tools at least in the online versions of the article. It can be very powerful to understand a dataset and make further use of it for your own research 🌊

a-ferderer.github.io/Interactive_...

Dynamic Scatter Plot with Error Bars

a-ferderer.github.io

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Lennart Bach @bachlennart.bsky.social · 20d

6/n
And OA?

Increased H+ (reduced pH) associated with OA reduces growth rate in all species, but differently between them. Some are very resilient, whereas others are more sensitive. OA would not "kill all diatoms" but may change their species composition (with implications for food webs).

🌊

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Lennart Bach @bachlennart.bsky.social · 20d

5/n
How does this inform OAE?

OAE aims to store atmospheric CO2 as bicarbonate (HCO3-) in the ocean. No effect of HCO3- on growth suggests limited effect of this intentional storage. However, OAE can unintentionally cause a transient decrease of CO2 and H+, thereby briefly reducing diatom growth.🌊

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Lennart Bach @bachlennart.bsky.social · 20d

4/n
Key finding 3:

The concentration of bicarbonate (HCO3-), had no discernable effect on growth of any of the 5 diatom species. This is remarkable, considering that HCO3- was shown to be a predominant C source for photosynthesis.

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Lennart Bach @bachlennart.bsky.social · 20d

3/n
Key finding 2:

While the response pattern to changing carbonate chemistry was identical between species (see finding 1), their sensitivities to CO2 and H+ concentration varied widely. Thus, different species have different carbonate chemistry niches, some being specialists, others generalists.🌊

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Lennart Bach @bachlennart.bsky.social · 20d

2/n
Key finding 1:

Diatom responses to carbonate chemistry are mostly (almost entirely) driven by changes in CO2 and H+ concentration (H+ = pH). Across a large gradient, diatom growth increases with increasing CO2, while decreasing with increasing H+.
🌊

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Lennart Bach @bachlennart.bsky.social · 20d

1/n
This study led by @aaronferderer.bsky.social tested how 5 diatom species respond to broad ranges of seawater carbonate conditions. Goal was to determine carbonate chemistry niches and to inform Ocean Alkalinity Enhancement (OAE) and Ocean Acidification (OA)

🌊

www.science.org/doi/10.1126/...

Carbonate chemistry fitness landscapes inform diatom resilience to future perturbations

Diatom growth rates are determined by concentrations of CO2 and H+ across broad carbonate chemistry landscapes.

www.science.org

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Lennart Bach @bachlennart.bsky.social · 21d

I was confused as well. My reading is that the whole ecosystem including phytoplankton ingestion, defacation, burial... makes it net negative.
As usual, the question is what is the carbon budget in the absence of the oyster farm.

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Lennart Bach @bachlennart.bsky.social · 23d

Congrats Jens!

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Lennart Bach @bachlennart.bsky.social · 29d

Finally a topic where the "moral hazard" argument may be more relevant than for CDR.

Matt Zoller Seitz @mattzollerseitz.bsky.social · 29d

"school shooting industry"

NPR @npr.org · 29d

The effort to keep schools safe from mass shooters has ballooned into a multibillion dollar industry. Companies are selling school districts assurance with high-tech products.

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Reposted by Lennart Bach

Mike Tyka @mtyka.bsky.social · Sep 4

Our new paper with Mengyang Zhou, Elizabeth Yankovsky, and Dustin Carroll is out as a preprint: egusphere.copernicus.org/preprints/20... "Substantial inter-model variation in OAE efficiency between the CESM2/MARBL and ECCO-Darwin ocean biogeochemistry models"

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Lennart Bach @bachlennart.bsky.social · Aug 28

Agree, references would have helped.

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Reposted by Lennart Bach

Jean-Pierre Gattuso @jpgattuso.bsky.social · Aug 27

A disaster for ocean and climate research is unfolding before our eyes. #NOAA 🌊
"The White House Office of Management and Budget is pulling back $239 million in funds Congress already provided. The biggest hits fall on climate and ocean research."
oceanpolicy.substack.com/p/roundup-un...

Roundup: Unobligated but Not Unnoticed: OMB Pulls Back NOAA Funds

August 12-26, 2025

oceanpolicy.substack.com

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Lennart Bach @bachlennart.bsky.social · Aug 27

Yes, it is not on solid foot

Reposted by Lennart Bach

Frauke Kracke @fraukekracke.bsky.social · Aug 26

Quick state of play on Ocean Alkalinity Enhancement (OAE): where the science stands, what recent trials show, and why it warrants careful, scaled testing. 🧵

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Lennart Bach @bachlennart.bsky.social · Aug 27

There is frustration with ocean iron fertilisation research/funding, which increasingly tranlates in attempts to argue against other CO2 removal pathways (here, alkalinity enhancement). This appears desparate rather than convincing/helpful. 🌊

climaterestoration.substack.com/p/iron-ferti...

Iron Fertilizer versus Antacids for the Ocean

Which approach could end the climate crisis?

climaterestoration.substack.com

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Lennart Bach @bachlennart.bsky.social · Aug 26

🌊
frontierclimate.com/writing/plan...

Frontier buyers sign $31M deal with Planetary to advance ocean alkalinity enhancement

Frontier has facilitated offtake agreements with Planetary, a company that removes atmospheric CO₂ and reduces local ocean acidity by adding dissolved alkaline minerals to seawater.

frontierclimate.com

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Lennart Bach @bachlennart.bsky.social · Aug 26

An excellent educational movie on the biological carbon pump.
🌊

www.youtube.com/watch?v=Rlfo...

The Platform | Main Trailer | Netflix

YouTube video by Netflix

www.youtube.com

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Reposted by Lennart Bach

Sabin Center for Climate Change Law @sabincenter.bsky.social · Aug 15

🌊📄 The Sabin Center published a new #report, International Legal Guidelines for Marine Carbon Dioxide Removal Governance under the London Convention and London Protocol.
Read here: scholarship.law.columbia.edu/sabin_climat...

#FridayReads

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Lennart Bach @bachlennart.bsky.social · Aug 18

Is linked in a better source for information than bluesky? I feel I am missing quite some interesting things on bluesky

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