Assessing the influence of ocean alkalinity enhancement on a coastal phytoplankton community

Biogeosciences, Journal Year: 2022, Volume and Issue: 19(23), P. 5375 - 5399

Published: Dec. 1, 2022

Abstract. Ocean alkalinity enhancement (OAE) is a proposed method to counteract climate change by increasing the of surface ocean and thus chemical storage capacity seawater for atmospheric CO2. The impact OAE on marine ecosystems, including phytoplankton communities which make up base food web, largely unknown. To investigate influence communities, we enclosed natural plankton community from coastal Tasmania 22 d in nine microcosms during spring bloom. Microcosms were split into three groups, (1) unperturbed control, (2) unequilibrated treatment where was increased (+495 ± 5.2 µmol kg−1) but CO2 not equilibrium with CO2, (3) equilibrated (+500 3.2 Both treatments have increase inorganic carbon sink 21 %. We found that simulated had significant generally moderate effects various groups heterotrophic bacteria. More pronounced observed diatom silicic acid drawdown biogenic silica build-up reduced at alkalinity. Observed changes affected temporal trends key biogeochemical parameters such as organic matter carbon-to-nitrogen ratio. Interestingly, did noticeably larger (and bacteria) than treatment, even though carbonate chemistry conditions much more severe. This particularly evident occurrence peak bloom experiment, different control. Altogether, inadvertent appear be rather limited relative enormous climatic benefit note, however, detailed widespread investigations responses are required confirm or dismiss this first impression.

Language: Английский

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Limits and CO₂equilibration of near-coast alkalinity enhancement

Biogeosciences, Journal Year: 2023, Volume and Issue: 20(1), P. 27 - 43

Published: Jan. 3, 2023

Abstract. Ocean alkalinity enhancement (OAE) has recently gained attention as a potential method for carbon dioxide removal (CDR) at gigatonne (Gt) scale, with near-coast OAE operations being economically favorable due to proximity mineral and energy sources. In this paper we study critical questions which determine the scale viability of OAE. Which coastal locations are able sustain large flux minimal pH ΩArag (aragonite saturation) changes? What is interference distance between adjacent projects? How much CO2 absorbed per unit added? quickly does induced deficiency equilibrate atmosphere? Choosing relatively conservative constraints on ΔpH or ΔOmega, examine limits using ECCO LLC270 (0.3∘) global circulation model. We find that sustainable rate varies over 1–2 orders magnitude different coasts exhibits complex patterns non-local dependencies vary from region region. general, in areas strong currents enables largest fluxes depending direction these currents, neighboring sites can exhibit far 400 km more. At steady state most regional stretches coastline accommodate order 10s 100s megatonnes negative emissions within 300 coast. conclude near-coastal globally several Gt yr−1 drawdown constraints, if effort spread majority available coastlines. Depending location, diverse set equilibration kinetics, determined by interplay gas exchange surface residence time. Most reach an uptake efficiency plateau 0.6–0.8 mol after 3–4 years, there only slow additional uptake. Regions significant downwelling (e.g., around Iceland) should be avoided deployments, such up half CDR lost bottom waters. The ideal locations, reaching molar ratio 0.8, include North Madagascar, California, Brazil, Peru close Southern Tasmania, Kerguelen Patagonia, where appears occur faster than However, some Hawaii) take significantly longer (up 8–10 years) but still eventually achieve high ratios.

Language: Английский

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Carbon sequestration in soils and climate change mitigation—Definitions and pitfalls

Global Change Biology, Journal Year: 2023, Volume and Issue: 30(1)

Published: Oct. 31, 2023

Abstract The term carbon (C) sequestration has not just become a buzzword but is something of siren's call to scientific communicators and media outlets. Carbon the removal C from atmosphere storage, for example, in soil. It potential partially compensate anthropogenic greenhouse gas emissions is, therefore, an important piece global climate change mitigation puzzle. However, often used misleadingly and, while likely unintentional, can lead perpetuation biased conclusions exaggerated expectations about its contribution efforts. Soils have considerable take up many are also state continuous loss. In such soils, measures build soil may only reduction losses (C loss mitigation) rather than result real negative emissions. examination 100 recent peer‐reviewed papers on topics surrounding C, 4% were found correctly. Furthermore, 13% equated with stocks. review, further, revealed that leading will always when non‐CO 2 gases leakage taken into consideration. This paper highlights pitfalls using incorrectly calls accurate usage this going forward. Revised new terms suggested distinguish clearly between SOC mitigation, emissions, accrual avoid miscommunication among scientists stakeholder groups future.

Language: Английский

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Deep-sea impacts of climate interventions

Science, Journal Year: 2023, Volume and Issue: 379(6636), P. 978 - 981

Published: March 10, 2023

Ocean manipulation to mitigate climate change may harm deep-sea ecosystems.

Language: Английский

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Assessing the technical aspects of ocean-alkalinity-enhancement approaches

State of the Planet, Journal Year: 2023, Volume and Issue: 2-oae2023, P. 1 - 29

Published: Nov. 27, 2023

Abstract. Ocean alkalinity enhancement (OAE) is an emerging strategy that aims to mitigate climate change by increasing the of seawater. This approach involves ocean enhance its capacity absorb and store carbon dioxide (CO2) from atmosphere. chapter presents overview technical aspects associated with full range OAE methods being pursued discusses implications for undertaking research on these approaches. Various have been developed implement OAE, including direct injection alkaline liquid into surface ocean; dispersal particles ships, platforms, or pipes; addition minerals coastal environments; electrochemical removal acid Each method has advantages challenges, such as scalability, cost effectiveness, potential environmental impacts. The choice technique may depend factors regional oceanographic conditions, source availability, engineering feasibility. considers methods, accelerated weathering limestone, liming, creation hydrated carbonates, environments. In each case, technologies are considered, best-practice drawn. social impacts will likely specific technology local context in which it deployed. Therefore, essential feasibility undertaken parallel with, informed by, wider impact assessments. While shows promise a mitigation strategy, acknowledge limitations uncertainties. Further development needed understand long-term effects, optimize techniques, address unintended consequences. should be viewed complementary extensive emission reductions, improved if operated using energy supply chains minimal CO2 emissions.

Language: Английский

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Beyond clean and affordable transition pathways: A review of issues and strategies to sustainable energy supply

International Journal of Electrical Power & Energy Systems, Journal Year: 2023, Volume and Issue: 155, P. 109544 - 109544

Published: Oct. 6, 2023

Expansion of the energy demand accompanies fossils' substitution for renewables, requiring sustainable pathways working through varying levels economic wealth and resource availability. Fossil reserves, renewable resources, transition metals, water, carbon storage sites are concentrated in a few countries, some relying on monetizing these resources to leverage growth. Accelerating from fossils renders cleaner while introducing co-benefits impacts, price pressure, safety issues. The affects energy-intensive sectors propagating clean strategies posing issues that may hinder development goals (SDG). A broader focus is needed, with clear vision many goals. work targer this gap targeted critical literature review identify industries prioritize. Among issues, capture mitigation most cited aspects. As evidenced by number citations reviewed works, waves progress among industries: Oil Gas, Cross Sectors Nations segments show fast responses occurring Energy industry, Mining, Heavy Truck, Aviation delayed decarbonization. response lags attributed uneven complexity achieving decarbonization sectors, which depend capital-intensive long-turnaround assets protective measures.

Language: Английский

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The additionality problem of ocean alkalinity enhancement

Biogeosciences, Journal Year: 2024, Volume and Issue: 21(1), P. 261 - 277

Published: Jan. 16, 2024

Abstract. Ocean alkalinity enhancement (OAE) is an emerging approach for atmospheric carbon dioxide removal (CDR). The net climatic benefit of OAE depends on how much it can increase CO2 sequestration relative to a baseline state without OAE. This so-called “additionality” be calculated as follows: Additionality=COAE-ΔCbaseline. So far, feasibility studies have mainly focussed enhancing in the oceans stimulate (COAE); however, primary focus has not been such anthropogenic would modify natural cycle and associated (ΔCbaseline). Here, I present incubation experiments which materials considered (sodium hydroxide, steel slag, olivine) are exposed beach sand investigate influence sources sinks. show that strongly reduce generation alkalinity, thereby reducing additionality. because increases calcium carbonate saturation state, reduces dissolution from sand, source. argue this “additionality problem” potentially widespread applies many marine systems where implementation – far beyond scenario investigated study. However, problem mitigated by dilute dosing into ocean environment avoidance cycling hotspots, sediments. Understanding potential slowdown through introduction will crucial assessment

Language: Английский

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Status and Outlook of Oil Field Chemistry-Assisted Analysis during the Energy Transition Period

Energy & Fuels, Journal Year: 2022, Volume and Issue: 36(21), P. 12917 - 12945

Published: Oct. 24, 2022

Analytical chemistry is powerful in analyzing complex mixtures of crude oil and brine subsurfaces on the basis atomic molecular levels. Geochemistry applies chemical principles experiments to understand earth science engineering problems. Crude oil's molecule structure, especially for resin asphaltenes, could only be understood using advanced analytical techniques. Fingerprinting geochemistry applied conventional unconventional reservoirs helps better identify hydrocarbon resources. Subsequently, reservoir fluid geodynamics (RFG) discipline promoted because gap between basin modeling simulation models with data. Fluid migration elaborated from geological time when trap was formed nowadays span millions years. Also, asphaltene data used delineate compartmentalization. This work reviews state-of-art theory technology upstream gas industry proposes an improvement high-resolution power efficient sustainable energy development.

Language: Английский

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Seawater carbonate chemistry considerations for ocean alkalinity enhancement research: theory, measurements, and calculations

State of the Planet, Journal Year: 2023, Volume and Issue: unknown, P. 1 - 1

Published: Nov. 27, 2023

Abstract. Ocean alkalinity enhancement (OAE) is a proposed marine carbon dioxide removal (mCDR) approach that has the potential for large-scale uptake of significant amounts atmospheric (CO₂). Removing anthropogenic legacy CO₂ will be required to stabilise global surface temperatures below 1.5–2 ^∘C Paris Agreement target 2015. In this chapter we describe impacts various OAE feedstocks on seawater carbonate chemistry, as well pitfalls need avoided during sampling, storage, and measurement four main chemistry parameters, i.e. dissolved inorganic (DIC), total (TA), pH, fugacity (fCO₃) might have been precipitated upon increase it otherwise interfere with number analyses; (3) samples DIC can stabilised avoid risk CaCO₃ precipitation sample storage; (4) some require additional adjustments using available programs routines, instance if magnesium or concentrations modified.

Language: Английский

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Considerations for hypothetical carbon dioxide removal via alkalinity addition in the Amazon River watershed

Biogeosciences, Journal Year: 2023, Volume and Issue: 20(10), P. 1963 - 1977

Published: May 26, 2023

Abstract. The Amazon River plume plays a critical role in shaping the carbonate chemistry over vast area western tropical North Atlantic. We conduct sensitivity analysis of hypothetical ocean alkalinity enhancement (OAE) via quicklime addition watershed, examining response and air–sea carbon dioxide flux to addition. Through series tests, we show that detectability OAE-induced increment depends on perturbation strength (or size addition, ΔTA) number samples: there is 90 % chance meet minimum requirement with ΔTA>15 µmol kg−1 sample >40, given background variability 15–30 kg−1. pCO2 reduction at surface would range between 0–25 µatm when ΔTA=20 kg−1, decreasing increasing salinity (S). Adding 20 river mouth could elevate total uptake (15<S<35) by least 0.07–0.1 Mt CO2 per month, major portion occur saltiest region (S>32) due its large size, comprising approximately 80 S>15 area. However, lowest-salinity (S<15) has greater drop partial pressure (pCO2sw) low buffer capacity, potentially allowing for observational pCO2sw this region. Reduced outgassing part plume, while more uncertain, may also be important additional uptake. Such tests are useful designing minimalistic field trials setting achievable goals monitoring, reporting, verification purposes.

Language: Английский

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