Description: Accurately predicting future ocean acidification (OA) conditions is crucial for advancing OA research at regional and global scales, and guiding society's mitigation and adaptation efforts. This study presents a new model-data fusion product covering 10 global surface OA indicators based on 14 Earth System Models (ESMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6), along with three recent observational ocean carbon data products. The indicators include fugacity of carbon dioxide, pH on total scale, total hydrogen ion content, free hydrogen ion content, carbonate ion content, aragonite saturation state, calcite saturation state, Revelle Factor, total dissolved inorganic carbon content, and total alkalinity content. The evolution of these OA indicators is presented on a global surface ocean 1° × 1° grid as decadal averages every 10 years from preindustrial conditions (1750), through historical conditions (1850–2010), and to five future Shared Socioeconomic Pathways (2020–2100): SSP1-1.9, SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5. These OA trajectories represent an improvement over previous OA data products with respect to data quantity, spatial and temporal coverage, diversity of the underlying data and model simulations, and the provided SSPs. The generated data product offers a state-of-the-art research and management tool for the 21st century under the combined stressors of global climate change and ocean acidification. The gridded data product is available in NetCDF at the National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information: https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0259391.html, and global maps of these indicators are available in jpeg at: https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/synthesis/surface-oa-indicators.html. Key Points: - This study presents the evolution of 10 ocean acidification (OA) indicators in the global surface ocean from 1750 to 2100 - By leveraging 14 Earth System Models (ESMs) and the latest observational data, it represents a significant advancement in OA projections - This inter-model comparison effort showcases the overall agreements among different ESMs in projecting surface ocean carbon variables

Description: The carbon cycle component of the newly developed Earth System Model of intermediate complexity CLIMBER-X is presented. The model represents the cycling of carbon through atmosphere, vegetation, soils, seawater and marine sediments. Exchanges of carbon with geological reservoirs occur through sediment burial, rock weathering and volcanic degassing. The state-of-the-art HAMOCC6 model is employed to simulate ocean biogeochemistry and marine sediments processes. The land model PALADYN simulates the processes related to vegetation and soil carbon dynamics, including permafrost and peatlands. The dust cycle in the model allows for an interactive determination of the input of the micro-nutrient iron into the ocean. A rock weathering scheme is implemented into the model, with the weathering rate depending on lithology, runoff and soil temperature. CLIMBER-X includes a simple representation of the methane cycle, with explicitly modelled natural emissions from land and the assumption of a constant residence time of CH4 in the atmosphere. Carbon isotopes 13C and 14C are tracked through all model compartments and provide a useful diagnostic for model-data comparison. A comprehensive evaluation of the model performance for present–day and the historical period shows that CLIMBER-X is capable of realistically reproducing the historical evolution of atmospheric CO2 and CH4, but also the spatial distribution of carbon on land and the 3D structure of biogeochemical ocean tracers. The analysis of model performance is complemented by an assessment of carbon cycle feedbacks and model sensitivities compared to state-of-the-art CMIP6 models. Enabling interactive carbon cycle in CLIMBER-X results in a relatively minor slow-down of model computational performance by ~20 %, compared to a throughput of ~10,000 simulation years per day on a single node with 16 CPUs on a high performance computer in a climate–only model setup. CLIMBER-X is therefore well suited to investigate the feedbacks between climate and the carbon cycle on temporal scales ranging from decades to 〉100,000 years.

Description: Net-zero climate policies foresee deployment of atmospheric carbon dioxide removal wit geological, terrestrial, or marine carbon storage. While terrestrial and geological storage would be governed under the framework of national property rights, marine storage implies that carbon is transferred from one global common, the atmosphere, to another global common, the ocean, in particular if storage exceeds beyond coastal applications. This paper investigates the option of carbon dioxide removal (CDR) and storage in different (marine) reservoir types in an analytic climate-economy model, and derives implications for optimal mitigation efforts and CDR deployment. We show that the introduction of CDR lowers net energy input and net emissions over the entire time path. Furthermore, CDR affects the Social Cost of Carbon (SCC) via changes in total economic output but leaves the analytic structure of the SCC unchanged. In the first years after CDR becomes available the SCC is lower and in later years it is higher compared to a standard climate-economy model. Carbon dioxide emissions are first higher and then lower relative to a world without CDR. The paper provides the basis for the analysis of decentralized and potentially non-cooperative CDR policies.

Description: Ocean alkalinity enhancement (OAE) seeks to increase the alkalinity of seawater for carbon dioxide removal (CDR). Following numerous propositions to trial, test, or upscale OAE for CDR, multiple social considerations have begun to be identified. To ensure that OAE research is responsible (is attentive to societal priorities) and successful (does not prematurely engender widespread social rejection), it will be critical to understand how OAE might be perceived as risky or controversial and under what conditions it might be regarded by relevant social groups as most worthy of exploration. To facilitate the answering of these questions, this chapter does the following: (1) characterizes what is known to date about public perceptions of OAE, (2) provides methodological suggestions on how to conduct social science research and public engagement to accompany OAE field research, and (3) addresses how knowledge gained from social research and public engagement on OAE can be integrated into ongoing scientific, siting, and communications work.

Description: A common challenge in many ocean-based negative emissions technologies (NETs) is the difficulty of developing new global industries and supply chains, which could be necessary for their much needed rapid and large-scale deployment. Therefore, to facilitate roll-out, existing industries and infrastructure should preferably be utilised. For ocean alkalinity enhancement (OAE) by CaO, i.e., ocean liming (OL), the lime can be produced by calcination of limestone using the spare capacity in the cement industry. For OAE by NaOH, i.e., electrochemical brine splitting (EBS), the NaOH can be produced by electrolysis of waste brines from the desalination sector. In this case study, we investigate the realistic OAE potential of Spain, because of its large availability of limestone, its increasing spare cement kiln capacity, and its large and growing desalination industry. This case study shows Spain has a high potential for alkalinity addition to the oceans. Specifically, the total CDR capacity of Spain via OAE is 24.4 Mt yr.-1 with contributions of 22.6 Mt of CO2 removed by OL and 1.8 Mt of CO2 removed by EBS, assuming these processes are driven solely by renewable energy. Further, this case study provides a realistic estimate of the CO2 removal potential and life cycle emissions for alkalinity enhancement for a given region, in contrast to more general global or continental studies before it. By doing so, Spain’s annual carbon dioxide removal (CDR) capacity by OAE is also identified. Future work will look to include coastal enhanced weathering of olivine to the portfolio of Spain’s OAE approaches.

Description: Accessible seafloor minerals located near mid‐ocean ridges are noticed to mitigate the projected metal demands of the net‐zero energy transition, promoting growing interest in quantifying the global distributions of seafloor massive sulfides (SMS). Mineral potentials are commonly estimated using geophysical and geological data that lastly rely on additional confirmation studies using sparsely available, locally limited, seafloor imagery, grab samples, and coring data. This raises the challenge of linking in situ confirmation data to geophysical data acquired at disparate spatial scales to obtain quantitative mineral predictions. Although multivariate data sets for marine mineral research are incessantly acquired, robust, integrative data analysis requires cumbersome workflows and experienced interpreters. We introduce an automated two‐step machine learning approach that integrates the mound detection through image segmentation with geophysical data. SMS predictors are subsequently clustered into distinct classes to infer marine mineral potentials that help guide future exploration. The automated workflow employs a U‐Net convolutional neural network to identify mound structures in bathymetry data and distinguishes different mound classes through the classification of mound architectures and magnetic signatures. Finally, controlled source electromagnetic data are utilized together with in situ sampling data to reassess predictions of potential SMS volumes. Our study focuses on the Trans‐Atlantic Geotraverse area, which is among the most explored SMS areas worldwide and includes 15 known SMS sites. The automated workflow classifies 14 of the 15 known mounds as exploration targets of either high or medium priority. This reduces the exploration area to less than 7% of the original survey area from 49 to 3.1 km 2 . Key Points A two‐step machine learning workflow identifies mound structures in bathymetry data and classifies their origins based on auxiliary data Significant increase in potential seafloor massive sulfides (SMS) edifices detected within the trans‐Atlantic geo‐traverse hydrothermal field distributed within latitudinal bands SMS mineral potential is likely lower than previously assumed due to heterogeneously distributed mineralization within mounds

Description: Science Board Meeting 2022 — Note from the Science Board Chair. FUTURE SSC’s 8th Annual Meeting ~ Highlights. PICES-2022 and the first hybrid annual meeting. Featuring PICES-2022 Award recipients: (Chair Award, Wooster Award, Zhu-Peterson Award, PICES Ocean Monitoring Service Award, ECS Best Presentation Awards). PICES-2022 Workshop Reports: (W1: Distributions of pelagic, demersal, and benthic species associated with seamounts in the North Pacific Ocean and factors influencing their distributions, W2: Integrated Ecosystem Assessment (IEA) to understand the present and future of the Central Arctic Ocean (CAO) and Northern Bering and Chukchi Seas (NBS-CS), W3: SmartNet: Promoting PICES and ICES Leadership in the UN Decade of Ocean Science for Sustainable Development, W4: Exploring Engagement Opportunities for Early Career Ocean Professionals (ECOPs) within PICES and Internationally, W5: Integrating biological research, fisheries science and management of broadly distributed flatfish species across the North Pacific Ocean in the face of climate and environmental variability, W7: Anthropogenic stressors, mechanisms and potential impacts on Marine Birds, Mammals, and Sea Turtles, W8: Science Communication Training: How to Create Memorable PICES Science Stories, W10: A TCODE Workshop on “Openly Discoverable, Accessible, and Reusable Data and Information in the U.N. Decade”). PICES AP-NPCOOS "Ocean Big Data" Summer School. PICES AP-CREAMS Virtual Summer School on Ocean Turbulence: From Observing to Research. Science and Innovation to Scale Up Ocean Action: UN Ocean Conference 2022. ECOP Perspective on the 4th Early Career Scientist Conference (ECSC4). Symposium in Lisbon Re-unites the Global Community Investigating Small Pelagic Fish. SPF2022 Symposium Workshop Reports: (1: Application of Genetics to Small Pelagic Fish, 2: The Devil’s in the Details of Using Species Distribution Models to Inform Multispecies and Ecosystem Models, 3: Small Pelagics for Whom? Challenges and Opportunities for the Equitable Distribution of Nutritional Benefits, 4: Evaluating Inter-Sectoral Tradeoffs and Community-Level Response to Spatio-Temporal Changes in Forage Distribution and Abundance, 5: Recent Advances in the Daily Egg Production Method (DEPM): Challenges and Opportunities, 6: Small Pelagic Fish Reproductive Resilience). SOLAS Open Science Conference, 2022. Early Career Scientist Participation in SOLAS Open Science Conference, 2022. PICES SeaTurtle researchers find clues linking derelict fishing lines of “Urban Fishermen” to sea turtle stranding. NPAFC's IYS Synthesis Symposium - Key Takeaways. The Bering Sea: Current Status and Recent Trends. Western North Pacific: Current status and recent topic: Sea Surface Temperature during the 2022 warm season, The Northeast Pacific: Update on marine heatwave status and trends. PICES Events Calendar. PICES by the Numbers, and an Invitation to join SG-GREEN. Open call for PICES Press submissions | About PICES Press

Description: Published

Description: Non Refereed

Description: This deliverable provides a summary of a two-day expert workshop conducted in hybrid format. The workshop’s primary objective was aimed towards identifying future opportunities within the global ocean governance regime to strengthen governance of ocean-based NETs in a comprehensive manner. The workshop was organised by the Research Institute for Sustainability – Helmholtz Centre Potsdam (RIFS) as part of the work of Task 2.2 of the OceanNETs project. This deliverable follows a first online workshop (see Deliverable 2.3) that identified challenges within the current governance framework for ocean-based NETs. The second workshop consisted of breakout groups and plenary discussions designed to explore scenarios that reflect on identified governance challenges within the current and potential future global ocean governance regimes. Participants were asked to reflect on the concept of „good governance” and develop responses to the scenarios presented through specific prompts. They were encouraged to actively contribute to discussions that aimed to advance our understanding of the future governance of ocean-based NETs.

Description: Nitrogen (N) and phosphorus (P) biogeochemical dynamics are crucial for the regulation of the terrestrial carbon cycle. In Earth system models (ESMs) the implementation of nutrient limitations has been shown to improve the carbon cycle feedback representation and, hence, the fidelity of the response of land to simulated atmospheric CO2 rise. Here we aimed to implement a terrestrial N and P cycle in an Earth system model of intermediate complexity to improve projections of future CO2 fertilization feedbacks. The N cycle is an improved version of the Wania et al. (2012) N module, with enforcement of N mass conservation and the merger with a deep land-surface and wetland module that allows for the estimation of N2O and NO fluxes. The N cycle module estimates fluxes from three organic (litter, soil organic matter and vegetation) and two inorganic ( and ) pools and accounts for inputs from biological N fixation and N deposition. The P cycle module contains the same organic pools with one inorganic P pool; it estimates influx of P from rock weathering and losses from leaching and occlusion. Two historical simulations are carried out for the different nutrient limitation setups of the model: carbon and nitrogen (CN), as well as carbon, nitrogen and phosphorus (CNP), with a baseline carbon-only simulation. The improved N cycle module now conserves mass, and the added fluxes (NO and N2O), along with the N and P pools, are within the range of other studies and literature. For the years 2001–2015 the nutrient limitation resulted in a reduction of gross primary productivity (GPP) from the carbon-only value of 143 to 130 Pg C yr−1 in the CN version and 127 Pg C yr−1 in the CNP version. This implies that the model efficiently represents a nutrient limitation over the CO2 fertilization effect. CNP simulation resulted in a reduction of 11 % of the mean GPP and a reduction of 23 % of the vegetation biomass compared to the baseline C simulation. These results are in better agreement with observations, particularly in tropical regions where P limitation is known to be important. In summary, the implementation of the N and P cycle has successfully enforced a nutrient limitation in the terrestrial system, which has now reduced the primary productivity and the capacity of land to take up atmospheric carbon, better matching observations.

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