Lennart Bach
@bachlennart.bsky.social
Applied Marine Biogeochemist, Global Citizen, Mate // Investigating consequences of, and solutions for, the climate crisis // Based at the University of Tasmania // https://appliedbgc.imas.utas.edu.au/
Reposted by Lennart Bach
@agu.org New in #JGR a study on 🌊 Ocean Alkalinity Enhancement: higher alkalinity speeds up growth of key #coccolithophores, but at very high TA calcification falters & shells deform. Authors suggest TA <~3,000 μmol kg−1 as a safer ecosystem boundary. doi.org/10.1029/2025... #protistsonsky
The Physiological Response of Contrasting Coccolithophore Species to Ocean Alkalinity Enhancement
Increased alkalinity significantly boosts growth rates of coccolithophores Gephyrocapsa huxleyi and Coccolithus braarudii
Divergent responses between species arise as large C. braarudii rely on C...
doi.org
November 17, 2025 at 5:51 PM
@agu.org New in #JGR a study on 🌊 Ocean Alkalinity Enhancement: higher alkalinity speeds up growth of key #coccolithophores, but at very high TA calcification falters & shells deform. Authors suggest TA <~3,000 μmol kg−1 as a safer ecosystem boundary. doi.org/10.1029/2025... #protistsonsky
"Natural CO2 removal is increasingly being claimed as anthropogenic climate mitigation. This misrepresentation is already prevalent for forests and coastal ecosystems; there is now the risk of the error reoccurring for open-ocean CO2 uptake via the biological carbon pump."\
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rdcu.be/eOooz
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rdcu.be/eOooz
Natural carbon uptake by ocean biology will not deliver credible carbon credits
Nature Reviews Earth & Environment - Natural CO2 removal is increasingly being claimed as anthropogenic climate mitigation. This misrepresentation is already prevalent for forests and coastal...
rdcu.be
November 6, 2025 at 7:45 AM
"Natural CO2 removal is increasingly being claimed as anthropogenic climate mitigation. This misrepresentation is already prevalent for forests and coastal ecosystems; there is now the risk of the error reoccurring for open-ocean CO2 uptake via the biological carbon pump."\
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rdcu.be/eOooz
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rdcu.be/eOooz
A new guide on best practices for engaging coastal communities on ocean alkalinity enhancement by Sara Nawaz and Giulia Belotti.
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edspace.american.edu/carbonremova...
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edspace.american.edu/carbonremova...
edspace.american.edu
October 29, 2025 at 2:34 AM
A new guide on best practices for engaging coastal communities on ocean alkalinity enhancement by Sara Nawaz and Giulia Belotti.
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edspace.american.edu/carbonremova...
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edspace.american.edu/carbonremova...
Kind words by Mallory Ringham from Ebb Carbon about research informing the "Ocean Alkalinity Enhancement Pelagic Impact Intercomparison Project" #OAEPIIP.
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Agreed, the key benefit of OAEPIIP is bringing the OAE research community together.
onlinelibrary.wiley.com/doi/full/10....
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Agreed, the key benefit of OAEPIIP is bringing the OAE research community together.
onlinelibrary.wiley.com/doi/full/10....
October 27, 2025 at 12:45 AM
Kind words by Mallory Ringham from Ebb Carbon about research informing the "Ocean Alkalinity Enhancement Pelagic Impact Intercomparison Project" #OAEPIIP.
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Agreed, the key benefit of OAEPIIP is bringing the OAE research community together.
onlinelibrary.wiley.com/doi/full/10....
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Agreed, the key benefit of OAEPIIP is bringing the OAE research community together.
onlinelibrary.wiley.com/doi/full/10....
Reposted by Lennart Bach
Some of the climate benefits of forestry and revegetation projects are erased by the fact that they reduce the reflectivity of Earth's surface. 🧪
Accounting for albedo in carbon market protocols - Nature Communications
The paper analyzes the impact of omitting biophysical effects from carbon credits on climate mitigation. It shows that some Voluntary Carbon Market projects may result in net warming due to albedo whi...
www.nature.com
October 26, 2025 at 10:17 PM
Some of the climate benefits of forestry and revegetation projects are erased by the fact that they reduce the reflectivity of Earth's surface. 🧪
Reposted by Lennart Bach
Last week we hosted the 4th webinar in our GGR Insights series. In 'Making space for "place" in carbon removal: learning from the communities of St Ives Bay', we explored a marine CO2 removal trial in Cornwall & the community response to it. Watch the recording on YouTube: youtu.be/_MgoETf3-Sg?...
Making space for “place” in carbon removal: learning from the communities of St Ives Bay
This is a recording of the fourth webinar in the GGR Insights series, which presents the latest research and debates what is needed to enable the sustainable scale-up of greenhouse gas removal in the…
youtu.be
October 23, 2025 at 1:30 PM
Last week we hosted the 4th webinar in our GGR Insights series. In 'Making space for "place" in carbon removal: learning from the communities of St Ives Bay', we explored a marine CO2 removal trial in Cornwall & the community response to it. Watch the recording on YouTube: youtu.be/_MgoETf3-Sg?...
Reposted by Lennart Bach
🌊 New paper out today: Assessing the interaction between ocean alkalinity enhancement 🚢 and phytoplankton🦠 in an Earth System Model 🌐
#mCDR #OAE #ESM
bg.copernicus.org/articles/22/...
#mCDR #OAE #ESM
bg.copernicus.org/articles/22/...
Interactions between ocean alkalinity enhancement and phytoplankton in an Earth system model
Abstract. The functioning and efficiency of ocean alkalinity enhancement (OAE) as a CO2 removal strategy is well investigated in model studies, but risks for the ecosystem are presently not considered...
bg.copernicus.org
October 22, 2025 at 3:06 PM
🌊 New paper out today: Assessing the interaction between ocean alkalinity enhancement 🚢 and phytoplankton🦠 in an Earth System Model 🌐
#mCDR #OAE #ESM
bg.copernicus.org/articles/22/...
#mCDR #OAE #ESM
bg.copernicus.org/articles/22/...
Reposted by Lennart Bach
Hello! we have a new paper out today in @science.org reviewing Calcifying Plankton : from Biomineralization to Global change 🌊🧪🐚
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
Calcifying plankton: From biomineralization to global change
The cycling of calcium carbonate (CaCO3) in the ocean is closely linked to seawater alkalinity and the regulation of atmospheric CO2. In the modern pelagic ocean, almost all CaCO3 is produced by three...
www.science.org
October 23, 2025 at 8:29 PM
Hello! we have a new paper out today in @science.org reviewing Calcifying Plankton : from Biomineralization to Global change 🌊🧪🐚
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
Reposted by Lennart Bach
Happy #FieldworkFriday from our SUSTech students who are busy in Dapeng running large-scale incubations to look at the side-effects of Ocean Alkalinity Enhancement on marine ecosystems 🌊
October 17, 2025 at 2:49 AM
Happy #FieldworkFriday from our SUSTech students who are busy in Dapeng running large-scale incubations to look at the side-effects of Ocean Alkalinity Enhancement on marine ecosystems 🌊
Still looking for 1 more guest editor :-)
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We are currently proposing a special issue in Biogeosciences to publish individual experiments of the "Ocean Alkalinity Enhancement Pelagic Impact Intercomparison Project #OAEPIIP".
Let me know if you are keen to serve as guest editors for the special issue ☺️
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bg.copernicus.org/articles/21/...
Let me know if you are keen to serve as guest editors for the special issue ☺️
🌊
bg.copernicus.org/articles/21/...
Technical note: Ocean Alkalinity Enhancement Pelagic Impact Intercomparison Project (OAEPIIP)
Abstract. Ocean alkalinity enhancement (OAE) aims to transfer carbon dioxide (CO2) from the atmosphere to the ocean by increasing the capacity of seawater to store CO2. The potential effects of OAE-in...
bg.copernicus.org
October 17, 2025 at 2:27 AM
Still looking for 1 more guest editor :-)
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It is good to see that a diverse set of stakeholders from Tasmania have a nuanced view on marine CO2 removal, specifically Ocean Alkalinity Enhancement.
This is encouraging and, indeed, important to follow their request and inform the public more.
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www.nature.com/articles/s43...
This is encouraging and, indeed, important to follow their request and inform the public more.
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www.nature.com/articles/s43...
Stakeholders have knowledge priorities beyond local impacts for responsible marine-based carbon dioxide removal in Tasmania - Communications Earth & Environment
Tasmanian stakeholders require targeted knowledge on ocean alkalinity enhancement to develop informed views, particularly regarding feasibility, impacts, governance, and policy objectives, according t...
www.nature.com
October 17, 2025 at 2:26 AM
It is good to see that a diverse set of stakeholders from Tasmania have a nuanced view on marine CO2 removal, specifically Ocean Alkalinity Enhancement.
This is encouraging and, indeed, important to follow their request and inform the public more.
🌊
www.nature.com/articles/s43...
This is encouraging and, indeed, important to follow their request and inform the public more.
🌊
www.nature.com/articles/s43...
"Carbon credits are failing to help with climate change — here’s why.
The idea that emissions can be offset through projects that claim to avoid releases or to remove carbon dioxide from the atmosphere is fatally flawed." by Macintosh et al.
www.nature.com/articles/d41...
The idea that emissions can be offset through projects that claim to avoid releases or to remove carbon dioxide from the atmosphere is fatally flawed." by Macintosh et al.
www.nature.com/articles/d41...
Carbon credits are failing to help with climate change — here’s why
The idea that emissions can be offset through projects that claim to avoid releases or to remove carbon dioxide from the atmosphere is fatally flawed.
www.nature.com
October 17, 2025 at 12:22 AM
"Carbon credits are failing to help with climate change — here’s why.
The idea that emissions can be offset through projects that claim to avoid releases or to remove carbon dioxide from the atmosphere is fatally flawed." by Macintosh et al.
www.nature.com/articles/d41...
The idea that emissions can be offset through projects that claim to avoid releases or to remove carbon dioxide from the atmosphere is fatally flawed." by Macintosh et al.
www.nature.com/articles/d41...
We are currently proposing a special issue in Biogeosciences to publish individual experiments of the "Ocean Alkalinity Enhancement Pelagic Impact Intercomparison Project #OAEPIIP".
Let me know if you are keen to serve as guest editors for the special issue ☺️
🌊
bg.copernicus.org/articles/21/...
Let me know if you are keen to serve as guest editors for the special issue ☺️
🌊
bg.copernicus.org/articles/21/...
Technical note: Ocean Alkalinity Enhancement Pelagic Impact Intercomparison Project (OAEPIIP)
Abstract. Ocean alkalinity enhancement (OAE) aims to transfer carbon dioxide (CO2) from the atmosphere to the ocean by increasing the capacity of seawater to store CO2. The potential effects of OAE-in...
bg.copernicus.org
October 16, 2025 at 3:32 AM
We are currently proposing a special issue in Biogeosciences to publish individual experiments of the "Ocean Alkalinity Enhancement Pelagic Impact Intercomparison Project #OAEPIIP".
Let me know if you are keen to serve as guest editors for the special issue ☺️
🌊
bg.copernicus.org/articles/21/...
Let me know if you are keen to serve as guest editors for the special issue ☺️
🌊
bg.copernicus.org/articles/21/...
Reposted by Lennart Bach
Lethal by design? Guiding environmental assessments of ocean alkalinity enhancement toward realistic contextualization of the alkalinity perturbation. cdrxiv.org/preprint/457
Lethal by design? Guiding environmental assessments of ocean alkalinity enhancement toward realistic contextualization of the alkalinity perturbation – CDRXIV
Ocean Alkalinity Enhancement (OAE) aims to mitigate climate change by increasing the chemical capacity of seawater to store anthropogenic CO2. OAE can be implemented through multiple pathways, each of...
cdrxiv.org
October 14, 2025 at 9:55 PM
Lethal by design? Guiding environmental assessments of ocean alkalinity enhancement toward realistic contextualization of the alkalinity perturbation. cdrxiv.org/preprint/457
Reposted by Lennart Bach
Seagrasses are great but this is false. Most carbon in the ocean is dissolved inorganic carbon and seagrass carbon is a tiny fraction of that. The mixing of stock and flux is also unhelpful. The only way to stop climate change is not burning fossil fuels.
reasonstobecheerful.world/seagrass-res...
reasonstobecheerful.world/seagrass-res...
October 11, 2025 at 11:45 PM
Seagrasses are great but this is false. Most carbon in the ocean is dissolved inorganic carbon and seagrass carbon is a tiny fraction of that. The mixing of stock and flux is also unhelpful. The only way to stop climate change is not burning fossil fuels.
reasonstobecheerful.world/seagrass-res...
reasonstobecheerful.world/seagrass-res...
Reposted by Lennart Bach
Does ocean model resolution change how fast CO₂ equilibrates with the air?
In our new study with @bachlennart.bsky.social and @mtyka.bsky.social, we found small resolution effects but large inter-model spreads —highlighting the next goal for improving mCDR predictions. link: doi.org/10.1029/2024...
In our new study with @bachlennart.bsky.social and @mtyka.bsky.social, we found small resolution effects but large inter-model spreads —highlighting the next goal for improving mCDR predictions. link: doi.org/10.1029/2024...
October 10, 2025 at 3:49 AM
Does ocean model resolution change how fast CO₂ equilibrates with the air?
In our new study with @bachlennart.bsky.social and @mtyka.bsky.social, we found small resolution effects but large inter-model spreads —highlighting the next goal for improving mCDR predictions. link: doi.org/10.1029/2024...
In our new study with @bachlennart.bsky.social and @mtyka.bsky.social, we found small resolution effects but large inter-model spreads —highlighting the next goal for improving mCDR predictions. link: doi.org/10.1029/2024...
Interesting study by colleagues in Portugal.
Evaluating ocean alkalinity enhancement for carbon dioxide removal: evidence from a one-year saltmarsh field experiment
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egusphere.copernicus.org/preprints/20...
Evaluating ocean alkalinity enhancement for carbon dioxide removal: evidence from a one-year saltmarsh field experiment
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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
October 6, 2025 at 3:49 AM
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
🌊
egusphere.copernicus.org/preprints/20...
Reposted by Lennart Bach
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
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www.science.org/doi/10.1126/...
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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
October 3, 2025 at 12:04 AM
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
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www.science.org/doi/10.1126/...
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www.science.org/doi/10.1126/...
Reposted by Lennart Bach
🌟 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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🚢 Are you a passionate researcher ready to tackle climate change? Dive into the ERC-funded Deep-C project in Aix-en-Provence, France!
⬇️
September 29, 2025 at 10:01 AM
🌟 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!
⬇️
🚢 Are you a passionate researcher ready to tackle climate change? Dive into the ERC-funded Deep-C project in Aix-en-Provence, France!
⬇️
Reposted by Lennart Bach
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)
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www.science.org/doi/10.1126/...
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)
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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
September 19, 2025 at 1:10 AM
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/...
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/...
Finally a topic where the "moral hazard" argument may be more relevant than for CDR.
"school shooting industry"
September 10, 2025 at 3:45 AM
Finally a topic where the "moral hazard" argument may be more relevant than for CDR.
Reposted by Lennart Bach
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"
September 4, 2025 at 4:47 PM
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"
Reposted by Lennart Bach
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...
"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
August 27, 2025 at 5:32 AM
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...
"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...
Reposted by Lennart Bach
Quick state of play on Ocean Alkalinity Enhancement (OAE): where the science stands, what recent trials show, and why it warrants careful, scaled testing. 🧵
August 26, 2025 at 12:03 PM
Quick state of play on Ocean Alkalinity Enhancement (OAE): where the science stands, what recent trials show, and why it warrants careful, scaled testing. 🧵