Exploring Site‐Specific Carbon Dioxide Removal Options With Storage or Sequestration in the Marine Environment – The 10 Mt CO₂ yr⁻¹ Removal Challenge for Germany

Earth s Future, Journal Year: 2025, Volume and Issue: 13(4)

Published: April 1, 2025

Abstract Marine carbon dioxide removal (mCDR) and geological storage in the marine environment (mCS) promise to help mitigate global climate change alongside drastic emission reductions. However, implementable potential of mCDR mCS depends, apart from technology readiness, also on site‐specific conditions. In this work, we explore different options for mCS, using German context as a case study. We challenge each option remove 10 Mt CO 2 yr −1 , accounting 8%–22% projected hard‐to‐abate residual emissions Germany 2045. focus environmental, resource, infrastructure requirements individual at specific sites, within jurisdiction when possible. This serves an entry point discuss main uncertainty factors research needs beyond and, where possible, cost estimates, expected environmental effects, monitoring approaches. total, describe options; four aim enhancing chemical uptake ocean through alkalinity enhancement, blue ecosystems' sink capacity, two employ off‐shore storage. Our results indicate that five out would potentially be jurisdiction, three them could meet challenge. exercise example how creation more tangible CDR can provide basis assessment socio‐economic, ethical, political, legal aspects such implementations. The approach presented here easily applied other regional or national capacity considerations.

Language: Английский

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Ocean alkalinity enhancement (OAE) does not cause cellular stress in a phytoplankton community of the subtropical Atlantic Ocean

Biogeosciences, Journal Year: 2025, Volume and Issue: 22(7), P. 1865 - 1886

Published: April 16, 2025

Abstract. A natural plankton community from oligotrophic subtropical waters of the Atlantic near Gran Canaria, Spain, was subjected to varying degrees ocean alkalinity enhancement (OAE) assess potential physiological effects in context application carbon dioxide removal (CDR) techniques. We employed nine mesocosms with sediment traps attached bottom, each enclosing a volume 8.3 m3, create gradient total (TA). OAE based on addition carbonates (NaHCO3 and Na2CO3). The lowest point this 2400 µmol L−1, which corresponded environment, highest 4800 L−1. Over course 33 d experiment, exhibited two distinct phases. In phase I (days 5–20), notable decline photosynthetic efficiency (Fv/Fm) observed. This change accompanied by substantial reductions abundances picoeukaryotes, small-size nanoeukaryotes (nanoeukaryotes-1), microplankton. cell viability as indicated fluorescein diacetate hydrolysis cellular esterases (FDA green fluorescence), slightly increased end I, whilst nanoeukaryotes-1 Synechococcus spp. did not change. Reactive oxygen species levels (ROS fluorescence) showed no significant changes for any functional groups. contrast, II 21–33), pronounced response Increases Fv/Fm intermediate treatments Δ900 Δ1800 L−1 chlorophyll (Chl a), c2 c2), fucoxanthin, divinyl Chl were attributed emergence blooms large-size (nanoeukaryotes-2) genera Chrysochromulina, well picoeukaryotes. also flourished towards phase. parallel, we observed 20 % overall metaproteome phytoplankton community. is considered alteration protein expression, having impact functions physiology organisms. Medium ΔTA more upregulated less-downregulated proteins than higher treatments. Under these conditions, significantly pico- at levels, while spp., nanoeukaryotes-2 microplankton remained stable. ROS group. pigment ratios DD+DT : FUCO medium treatments, supporting idea nutrient deficiency alleviation absence stress. When all data are taken together, study shows that cause stress studied, fitness impaired. drawdown numbers times seemed have been most likely caused limitation.

Language: Английский

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Quantifying Regional Efficiency of Marine Carbon Dioxide Removal (mCDR) via Alkalinity Enhancement using the ECCO-Darwin Ocean Biogeochemistry State Estimate and an Idealized Vertical 1-D Model

Authorea (Authorea), Journal Year: 2024, Volume and Issue: unknown

Published: March 4, 2024

As a marine Carbon Dioxide Removal (mCDR) approach, Ocean Alkalinity Enhancement (OAE) is emerging as viable method for removing anthropogenic CO2 emissions from the atmosphere to mitigate climate change. To achieve substantial carbon reduction using this method, OAE would need be widespread and scaled-up across global ocean. However, efficiency of varies substantially range space-time scales such field deployments must carefully planned maximize minimize logistical costs risks. Here we develop mCDR framework based on data-assimilative ECCO-Darwin ocean biogeochemistry model, which examines two key factors over seasonal multi-decadal timescales: 1) potential, quantifies solubility upper ocean; 2) dynamical efficiency, representing full-depth impact advection, mixing, air-sea exchange. isolate quantify that determine reduced complexity 1-D rapid-mCDR, computationally-efficient tool evaluation efficiency. Combining rapid-mCDR model with allows rapid characterization at any location globally. This research contributes our understanding optimization (i.e., deploying experiments in real-world ocean) an effective strategy elucidates regional differences mechanistic processes The modeling tools developed study can readily employed by teams industry plan complement future provide essential Monitoring, Reporting, Verification (MRV).

Language: Английский

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Marine Carbon Dioxide Removal by alkalinization should no longer be overlooked

Environmental Research Letters, Journal Year: 2024, Volume and Issue: 19(7), P. 074033 - 074033

Published: May 29, 2024

Abstract To achieve the Paris climate target, deep emissions reductions have to be complemented with carbon dioxide removal (CDR). However, a portfolio of CDR options is necessary reduce risks and potential negative side effects. Despite large theoretical potential, ocean-based such as ocean alkalinity enhancement (OAE) has been omitted in change mitigation scenarios so far. In this study, we provide techno-economic assessment large-scale OAE using hydrated lime (‘ocean liming’). We address key uncertainties that determine overall cost liming (OL) CO2 uptake efficiency per unit material, distribution strategies avoiding carbonate precipitation which would compromise efficiency, technology availability (e.g., solar calciners). find at economic costs 130–295 $/tCO2 net-removed, could competitive option make significant contribution towards target. As identified no showstoppers, argue for more research on ecosystem impacts, governance, monitoring, reporting, verification, development whether other should considered part broader portfolio.

Language: Английский

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Review on CO2 removal from ocean with an emphasis on direct ocean capture (DOC) technologies

Separation and Purification Technology, Journal Year: 2024, Volume and Issue: 353, P. 128598 - 128598

Published: June 28, 2024

Language: Английский

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