Month: June 2024

Schwinger et al. (2024): On the emission-path dependency of the efficiency of ocean alkalinity enhancement

Jörg Schwinger, Timothée Bourgeois, Wilfried Rickels IN: Environmental Research Letters,

The chemical efficiency of OAE (the amount of CO2 sequestered per unit of alkalinity added) depends, among other factors, on the background state of the surface ocean, which will significantly change until the end of this century and beyond. Here, the authors investigate the consequences of such changes for the long-term efficiency of OAE. Our results suggest that the assumption of a constant, present-day chemical efficiency of OAE in integrated assessment modelling and carbon credit assignments could lead to economically inefficient OAE implementation pathways.


Karunarathne et al. (2024): Review on CO2 removal from ocean with an emphasis on direct ocean capture (DOC) technologies

Sumudu Karunarathne, Sara Andrenacci, Andres Carranza-Abaid, Chameera Jayarathna, Michel Maelum, Ragnhild Skagestad, Hans Aksel Haugen IN: Separation and Purification Technology,

Recent developments focus on maturing promising Carbon Dioxide Removal (CDR) technologies that remove and permanently store CO2. This article specifically examines a subset of CDR technologies referred to as ocean-based negative emission technologies (ONETs). The technologies under review involve modifications to seawater chemistry aimed at maximizing the ocean’s potential as a CO2 sink. Specifically, electrochemical ocean capture (EOC) and ocean alkalinity enhancement (OAE) are discussed.


Oppon et al. (2024): Sustainability performance of enhanced weathering across countries: A triple bottom line approach

Eunice Oppon, S.C. Lenny Koh, Rafael Eufrasio IN: Energy Economicy, 136,

There is limited research about the broad sustainability impacts in rolling enhanced weathering (EW) on a large scale. This research assesses the triple bottom line sustainability of EW in eight top-emitting countries using an extended input-output model.


Li et al. (2024): Estimation methods of wetland carbon sink and factors influencing wetland carbon cycle: a review

Lixin Li, Haibo Xu, Qian Zhang, Zhaoshun Zhan, Xiongwei Liang & Jie Xing IN: Carbon Research, 3,

In current studies, most research has focused on the impact of individual factors on wetland carbon sinks, often ignoring the interaction between various factors, which further leads to uncertainty in wetland carbon measurements. This paper aims to elucidate the process of the wetland carbon cycle, summarize the factors affecting wetland carbon sinks, and explore the interplay between various factors and their influence on wetland carbon sinks, aiming to provide theoretical support for the study of wetland carbon sinks. Additionally, this paper reviews the advantages and disadvantages of current wetland carbon measurement methods, proposes research directions for combining machine learning methods, identifies existing difficulties in current wetland carbon measurement, and offers suggestions to serve as a reference for future wetland carbon sink estimation and wetland management.


Europe and Germany’s Role in Catalyzing aTrillion-Euro Industry

Patrick Herhold, Johanna Pütz, Karan Mistry, Robin Bierganz, Phillip Spiekermann, Louisa Maier, German Association for Negative Emissions (DVNE) & Boston Consulting Group (BCG), June 2024

This report has three objectives:

  • The primary objective is to explore and demonstrate the economic potential of carbon dioxide removal (CDR), specifically for Europe and Germany.
  • Additionally, the report aims to provide a comprehensive overview of the quickly evolving CDR landscape while distinguishing CDR from other related concepts.
  • Lastly, the report emphasizes the need for swift and decisive action by providing a specific, stakeholder-oriented action plan to realize the economic potential outlined.


Villardon et al. (2024): Enhancing carbon dioxide uptake in biochar derived from husk biomasses: Optimizing biomass particle size and steam activation conditions

A. Villardon, A. Alcazar-Ruiz, F. Dorado, L. Sanchez- Silva IN: Journal of Environmental Chemical Engineering, 12, 5, 113352,

This research focuses on developing activated biochars for CO2 adsorption, evaluating the impact of particle size and steam activation conditions on almond shells (AS), pistachio shells (PS), and nut shells (NS), three crops that are grown worldwide. A literature review was carried out on the characteristic parameters that a biomass must have to produce a biochar of an acceptable quality to capture CO2. Initially, a physicochemical characterization of the selected biomasses was conducted, revealing high levels of volatiles (78–84 wt%), carbon (41–53 wt%), and inherent metals (Ca, K, Mg and Na). This process involved pyrolysis and activation under pre-established conditions, followed by CO2 adsorption analysis using thermogravimetry. Once the optimal particle size was determined, steam activation conditions were further optimized by varying temperature.


Bakkaloglu et al. (2024): The role of negative emissions technologies in the UK’s net-zero strategy

Semra Bakkaloglu, Matthias Mersch, Nixon Sunny, Christos N. Markides, Nilay Shah, Adam Hawkes IN: Cell Reports Sustainability,

Using a multiscale modeling approach, the authors explore NETs’ potential for a single country, the United Kingdom (UK). Here, they report that the UK has cost-effective potential to remove 79 MtCO2 per year by 2050, rising to 126–134 MtCO2 per year with well-integrated NETs in industrial clusters. Results highlight that biomass gasification for hydrogen generation with CCS is emerging as a key NET, despite biomass availability being a limiting factor. Moreover, solid DACCS systems utilizing industrial waste heat integration offer a solution to offsetting increases in demand from transportation and industrial sectors.


Monteagudo et al. (2024): Investigation of effectiveness of KOH-activated olive pomace biochar for efficient direct air capture of CO2

J.M. Monteagudo, A. Durán, M. Alonso, Anca-Iulia Stoica IN: Separation and Purification Technology, 352, 127997,

In this work, the activation of olive pomace biochar with potassium hydroxide, KOH, has been studied for its use as a CO2 adsorbent. The effectiveness of biochar activated with KOH at 750 °C in an inert N2 atmosphere was evaluated, using different mass ratios of biochar/KOH, 1:0.5, 1:1, and 1:2. Various characterisation analyses of the biochar were performed to determine its chemical composition, specific surface area, pore size and volume, structure, morphology, and functional groups. The adsorption isotherm was determined at atmospheric pressure and a temperature of 10 °C. The experimental equilibrium results were fitted to the Langmuir, Freundlich, and Temkin models. Additionally, the kinetic behavior of biochar/KOH as an adsorbent was studied, and dynamic experiments were conducted at atmospheric pressure and 10 °C.


Nature – Yang et al. (2024): Fast reduction of Atlantic SST threatens Europe-wide gross primary productivity under positive and negative CO2 emissions

Young-Min Yang, Jongsoo Shin, So-Won Park, Jae-Heung Park, Soon-Il An, Jong-Seong Kug, Sang-Wook Yeh, June-Yi Lee, Bin Wang, Tim Li, Nari Im IN: npj Climate and Atmospheric Science, 7,

In this study, the authors utilized large ensemble simulations with an Earth system model of full complexity to investigate the response of Gross Primary Production (GPP) to CO2 forcings. The findings reveal a significant asymmetry in the GPP response to CO2 ramp-up and symmetric ramp-down model experiments, especially in Europe, suggesting that GPP declines rapidly as CO2 levels decrease. Remarkably, during the CO2 removal period, the North Atlantic Sea surface temperature experienced cooling due to a delayed recovery of the Atlantic Meridional Overturning Circulation (AMOC). This cooling led to precipitation and soil moisture deficits, resulting in a rapid reduction in GPP. This asymmetry in GPP response holds consistent across multi-model simulations.


Epihov et al. (2024): Iron Chelation in Soil: Scalable Biotechnology for Accelerating Carbon Dioxide Removal by Enhanced Rock Weathering

Dimitar Z. Epihov, Steven A. Banwart, Steve P. McGrath, David P. Martin, Isabella L. Steeley, Vicky Cobbold, Ilsa B. Kantola, Michael D. Masters, Evan H. DeLucia, David J. Beerling IN: Environmental Science and Technology,

Here, the authors combine multiomics analyses of belowground microbiomes, laboratory-based dissolution studies, and incubation investigations of soils from field enhanced rock weathering (EW) trials to build the case for manipulating iron chelators in soil to increase EW efficiency and lower costs. Microbial siderophores are high-affinity, highly selective iron (Fe) chelators that enhance the uptake of Fe from soil minerals into cells. Applying RNA-seq metatranscriptomics and shotgun metagenomics to soils and basalt grains from EW field trials revealed that microbial communities on basalt grains significantly upregulate siderophore biosynthesis gene expression relative to microbiomes of the surrounding soil. Separate in vitro laboratory incubation studies showed that micromolar solutions of siderophores and high-affinity synthetic chelator (ethylenediamine-N,N′-bis-2-hydroxyphenylacetic acid, EDDHA) accelerate EW to increase CDR rates. Building on these findings, we develop a potential biotechnology pathway for accelerating EW using the synthetic Fe-chelator EDDHA that is commonly used in agronomy to alleviate the Fe deficiency in high pH soils.