iiinova — where your digital self keeps evolving

Reposted by Jens Hartmann

Universität Hamburg @uni-hamburg.de · 15/06/2026

Bei der Suche nach dem passenden Beruf sind viele Kinder durch ihren familiären Hintergrund benachteiligt. Um das zu ändern, untersucht Prof. Kira Weber von der Fakultät für Erziehungswissenschaft, welche Angebote der Berufsorientierung es gibt und wie sie verbessert werden können.

uni-hamburg.de

Für mehr Orientierung in der schulischen Berufsorientierung

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Jens Hartmann @geojenshartmann.bsky.social · 15/06/2026

Part 8: I am not sure if this satisfies you @davidho.bsky.social, but it might be worth to collect all ideas, and see how we learn with time what is possible.

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Jens Hartmann @geojenshartmann.bsky.social · 15/06/2026

Part 7b: In some case extra infrastructure might produce a win-win situation. E.g., building more biogas-production units using organic waste from WWTPs, or building more pyrolysis plants for using biomass remains, etc. We are still at the beginning to elaborate the full picture of possibilities.

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Jens Hartmann @geojenshartmann.bsky.social · 15/06/2026

Part 7a: There are other examples, which might be worth collecting, exploring. For all such examples there is a learning curve to hike up. Without some use of energy, it is not possible to capture CO2 in given examples. However, it might be worth to learn where and how it is suitable.

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Jens Hartmann @geojenshartmann.bsky.social · 15/06/2026

Part 6b: Other alkaline waste materials which normally are deposited away might also be used to capture the CO2 before. The transport of the material to a local biogenic CO2 source needs energy. Captured CO2 would be CDR.

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Jens Hartmann @geojenshartmann.bsky.social · 15/06/2026

Part 6a: During pyrolysis for producing biochar some carbon is transferred to CO2. This CO2 is normally emitted to the atmosphere. Using alkaline waste products, like steel slag, the CO2 can be transformed into carbonates like CaCO3. Carbonized steel slag can be used building things, like houses.

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Jens Hartmann @geojenshartmann.bsky.social · 15/06/2026

Part 5b: This reaction would produce mineralized water and is ideally equilibrated with the atmosphere before release. The mining, milling and transport of the limestone needs energy.

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Jens Hartmann @geojenshartmann.bsky.social · 15/06/2026

Part 5a: Example biogas production from organic remains in wastewater treatment facilities. The biogas is burned producing CO2. The CO2 is normally emitted to the atmosphere. The CO2 can be transferred into alkalinity reacting it in water with limestone or other suitable alkaline material.

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Jens Hartmann @geojenshartmann.bsky.social · 15/06/2026

Part 4b: This needs energy for milling & transport of limestone. Limestone is a natural product. Dissolution produces Ca2+ and HCO3-. Often limestone is already added. The process can be optimized, to increase CO2-capture-efficiency.

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Jens Hartmann @geojenshartmann.bsky.social · 15/06/2026

Part 4a: What options exist for CDR. Many. E.g. using existing infrastructure, like wastewater treatment plants. Our remains are digested in reactors, producing CO2, normally emitted to the atmosphere. Dosing additional alkaline material like limestone transfers CO2 into alkalinity.

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Jens Hartmann @geojenshartmann.bsky.social · 14/06/2026

Part 4: Energy is not binary - it is here or not. Energy is very differently available depending on location, energy grid, etc. Energy might be heat not used so far, but locally useful for CDR. Local energy maybe used to avoid CO2-emissions from processes like waste water treatment. Possibilities..

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Jens Hartmann @geojenshartmann.bsky.social · 14/06/2026

Exactly. This is why a learning exercise is useful to evaluate what is possible and identify meaningful pathways based on gained knowledge. There will be new things we are not thinking about now, or assumptions/parameters/etc will shift.

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Jens Hartmann @geojenshartmann.bsky.social · 14/06/2026

Part 3: Some CDR-option need energy, but are today not efficient enough to be attractive. They might be in the future when the systems are optimised. Such optimisation processes can take decades (cf PV). For not losing options it might make sense to use renewable energy today to start the learning.

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Jens Hartmann @geojenshartmann.bsky.social · 14/06/2026

Part 2: The upscaling process is slow (cf evolution PV or electric cars). Significant CDR seems to be needed in a few decades. Waiting with decade-long upscaling and learn what works at scale means losing decade(s) of learning, if all energy would be first used to “curtail” use of fossil energy.

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Jens Hartmann @geojenshartmann.bsky.social · 14/06/2026

Part 1: I try, not being an energy expert: Some CDR-option need energy. Upscaling from a little CDR from first of a kind reactor/mashine/system needs time. You start small and over the decades a portfolio of options grow, to the needed or demanded CDR-rate per year.

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Jens Hartmann @geojenshartmann.bsky.social · 13/06/2026

I assumed green energy of course and of course that fossil fuel emissions went down. These are the pitfalls of using only a few letters….

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Jens Hartmann @geojenshartmann.bsky.social · 13/06/2026

Being at the CDR conference in Milano this week I realised that the difference between the OAE-approaches equilibrated and CO2-non-equilibrated is not always present. The first is less impacting pH or saturation level of aragonite, less risk for TA-loss, and higher pCO2 directly after employment.

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Jens Hartmann @geojenshartmann.bsky.social · 13/06/2026

TA-DIC-Diagram in context of OAE showing pathways for equilibrated and non-CO2-equilibrated approaches. Source: bg.copernicus.org/articles/21/...

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Jens Hartmann @geojenshartmann.bsky.social · 13/06/2026

Attending the CO2-removal conference in Milano this week, made me realise, there is a hiking trip to do, considering upscaling of novel CDR-solutions. Abundance of inexpensive, ideally free excess energy, is something which needs more attention in the discussions, I think. @davidho.bsky.social

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Reposted by Jens Hartmann

Prof. Stefan Rahmstorf @rahmstorf.bsky.social · 10/01/2025

ARD und ZDF planen ein TV-Duell mit zwei Kanzlerkandidaten. Ratet mal mit welchen beiden.

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Reposted by Jens Hartmann

Nicolás Sánchez @nicolassanchez.bsky.social · 07/12/2024

Our paper is out! In this study, we investigate how zooplankton, key link in marine food webs, are affected by Ocean Alkalinity Enhancement, a carbon dioxide removal technique for climate protection. www.science.org/doi/10.1126/...

science.org

Plankton food web structure and productivity under ocean alkalinity enhancement

An oligotrophic metazoan zooplankton community remains stable after 33 days of CO2-equilibrated ocean alkalinity enhancement.

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Reposted by Jens Hartmann

David Ho @davidho.bsky.social · 07/12/2024

For those who are not marine chemists, this is the easiest way to see how adding alkalinity to the ocean lowers pCO₂ without changing dissolved inorganic carbon and potentially allows the ocean to take up more atmospheric CO₂. 🌊

The image depicts a phase diagram illustrating the relationship between total alkalinity and dissolved inorganic carbon in aquatic systems. Key processes such as photosynthesis, respiration, and CaCO₃ formation and dissolution are labeled, with arrows indicating the directions of alkalinity addition.

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Reposted by Jens Hartmann

GEOMAR Helmholtz Centre for Ocean Research Kiel @geomarkiel.bsky.social · 10/12/2024

How do marine food webs respond to increasing alkalinity? A GEOMAR study has assessed the impacts of a moderate Ocean Alkalinity Enhancement (OAE) application, showing that the effects on zooplankton are likely minimal and that the food web could remain stable. 🔗 www.geomar.de/en/news/arti...

geomar.de

How do marine food webs respond to increasing alkalinity?

06.12.2024/Kiel. To mitigate climate change, man-made carbon dioxide (CO2) emissions must be reduced as quickly and drastically as possible. Additionally, some of the CO2 already emitted needs to be s...

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