Description: Reconstructions of global hydroclimate during the Common Era (CE; the past ∼2000 years) are important for providing context for current and future global environmental change. Stable isotope ratios in water are quantitative indicators of hydroclimate on regional to global scales, and these signals are encoded in a wide range of natural geologic archives. Here we present the Iso2k database, a global compilation of previously published datasets from a variety of natural archives that record the stable oxygen (δ18O) or hydrogen (δ2H) isotopic compositions of environmental waters, which reflect hydroclimate changes over the CE. The Iso2k database contains 759 isotope records from the terrestrial and marine realms, including glacier and ground ice (210); speleothems (68); corals, sclerosponges, and mollusks (143); wood (81); lake sediments and other terrestrial sediments (e.g., loess) (158); and marine sediments (99). Individual datasets have temporal resolutions ranging from sub-annual to centennial and include chronological data where available. A fundamental feature of the database is its comprehensive metadata, which will assist both experts and nonexperts in the interpretation of each record and in data synthesis. Key metadata fields have standardized vocabularies to facilitate comparisons across diverse archives and with climate-model-simulated fields. This is the first global-scale collection of water isotope proxy records from multiple types of geological and biological archives. It is suitable for evaluating hydroclimate processes through time and space using large-scale synthesis, model–data intercomparison and (paleo)data assimilation. The Iso2k database is available for download at https://doi.org/10.25921/57j8-vs18 (Konecky and McKay, 2020) and is also accessible via the NOAA/WDS Paleo Data landing page: https://www.ncdc.noaa.gov/paleo/study/29593 (last access: 30 July 2020).

Description: This paper analyses and compares industry sector transformation strategies as envisioned in recent German, European and global deep decarbonisation scenarios. The first part of the paper identifies and categorises ten key strategies for deep emission reductions in the industry sector. These ten key strategies are energy efficiency, direct electrification, use of climateneutral hydrogen and/or synthetic fuels, use of biomass, use of CCS, use of CCU, increases in material efficiency, circular economy, material substitution and end-use demand reductions. The second part of the paper presents a meta-analysis of selected scenarios, focusing on the question of which scenario relies to what extent on the respective mitigation strategies. The key findings of the meta-analysis are discussed, with an emphasis on identifying those strategies that are commonly pursued in all or the vast majority of the scenarios and those strategies that are only pursued in a limited number of the scenarios. Possible reasons for differences in the choice of strategies are investigated. The paper concludes by deriving key insights from the analysis, including identifying the main uncertainties that are still apparent with regard to the future steps necessary to achieve deep emission reductions in the industry sector and how future research can address these uncertainties.

Description: Numerous potentially toxic plankton species commonly occur in the Black Sea, and phycotoxins have been reported. However, the taxonomy, phycotoxin profiles, and distribution of harmful microalgae in the basin are still understudied. An integrated microscopic (light microscopy) and molecular (18S rRNA gene metabarcoding and qPCR) approach complemented with toxin analysis was applied at 41 stations in the northwestern part of the Black Sea for better taxonomic coverage and toxin profiling in natural populations. The combined dataset included 20 potentially toxic species, some of which (Dinophysis acuminata, Dinophysis acuta, Gonyaulax spinifera, and Karlodinium veneficum) were detected in over 95% of the stations. In parallel, pectenotoxins (PTX-2 as a major toxin) were registered in all samples, and yessotoxins were present at most of the sampling points. PTX-1 and PTX-13, as well as some YTX variants, were recorded for the first time in the basin. A positive correlation was found between the cell abundance of Dinophysis acuta and pectenotoxins, and between Lingulodinium polyedra and Protoceratium reticulatum and yessotoxins. Toxic microalgae and toxin variant abundance and spatial distribution was associated with environmental parameters. Despite the low levels of the identified phycotoxins and their low oral toxicity, chronic toxic exposure could represent an ecosystem and human health hazard.

Description: This paper aims to develop the first differentiated (earlywood—EW, latewood—LW, and total ring width—RW) dendrochronological series for ash (Fraxinus excelsior L.) and oak (Quercus robur L.) trees from the Republic of Moldova, and to analyze their climatic response and their spatio-temporal stability. For this, 18 ash and 26 oak trees were cored from the DobruÈ�a protected area, Republic of Moldova, Eastern Europe, and new EW, LW, and RW chronologies were developed for ash and oak covering the last century. The obtained results showed that the RW and LW have a similar climatic response for both species, while EW is capturing interannual climate variations and has a different reaction. The analyses performed with monthly climatic data revealed a significant and negative correlation with the mean air temperature and a significant and positive correlation with precipitation and the Standardized Precipitation-Evapotranspiration Index (SPEI) for both ash and oak. The temperature during the vegetation period has a strong influence on all tree-ring components of ash, while for oak the strong correlation was found only for LW. The positive and significant correlation between LW and RW with precipitation for both species, suggests that ash and oak are sensitive to the hydrological component and the precipitation is the main tree growth-limiting factor. Despite the significant correlation with precipitation and temperature for the whole analyzed period, the 25-year moving correlation analyses show that they are not stable in time and can switch from positive to negative or vice versa, while the correlation with SPEI3 drought index, which is a integration of both climatic parameters, is stable in time. By employing the stability map analysis, we show that oak and ash tree ring components, from the eastern part of the Republic of Moldova, have a stable and significant correlation with SPEI3 and scPDSI drought indices from February (January) until September, over the eastern part of Europe.

Description: Bacterial diversity was explored among field samples and cultured isolates from coral reefs within the Veracruz Reef System. Bacterioplankton and bacteriobenthos were characterized by pyrosequencing 16S rRNA genes. Identified sequences belonged to the kingdom Bacteria and classified into 33 phyla. Proteobacteria (likely SAR11 clade) dominated in collective field samples, whereas Firmicutes were the most abundant taxa among cultured isolates. Bioinformatic sorting of sequences to family level revealed 223 bacterial families. Pseudomonadaceae, Exiguobacteraceae and Bacillaceae were dominant among cultured isolates. Vibrionaceae, Alteromonadaceae, and Flavobacteriaceae dominated in reef-associated sediments, whereas Rickettsiaceae and Synechoccaceae were more highly represented in the water column. Bacterial communities from sediments were more diverse than from the water column. This study reveals cryptic bacterial diversity among microenvironmental components of marine microbial reef communities subject to differential influence of anthropogenic stressors. Such investigations are critical for constructing scenarios of environmentally induced shifts in bacterial biodiversity and species composition.

Description: Recent studies on seafloor mapping have presented different modelling methods for the automatic classification of seafloor sediments. However, most of these studies have applied these models to seafloor data with appropriate numbers of ground-truth samples and without consideration of the imbalances in the ground-truth datasets. In this study, we aim to address these issues by conducting class-specific predictions using ensemble modelling to map seafloor sediment distributions with minimal ground-truth data combined with hydroacoustic datasets. The resulting class-specific maps were then assembled into a sediment classification map, in which the most probable class was assigned to the appropriate location. Our approach was able to predict sediment classes without bias to the class with more ground-truth data and produced reliable seafloor sediment distributions maps that can be used for seafloor monitoring. The methods presented can also be used for other underwater exploration studies with minimal ground-truth data. Sediment shifts of a heterogenous seafloor in the Sylt Outer Reef, German North Sea were also assessed to understand the sediment dynamics in the marine conservation area during two different short timescales: 2016–2018 (17 months) and 2018–2019 (4 months). The analyses of the sediment shifts showed that the western area of the Sylt Outer Reef experienced sediment fluctuations but the morphology of the bedform features was relatively stable. The results provided information on the seafloor dynamics, which can assist in the management of the marine conservation area.

Description: Various species of Alexandrium can produce a number of bioactive compounds, e.g., paralytic shellfish toxins (PSTs), spirolides, gymnodimines, goniodomins, and also uncharacterised bioactive extracellular compounds (BECs). The latter metabolites are released into the environment and affect a large range of organisms (from protists to fishes and mammalian cell lines). These compounds mediate allelochemical interactions, have anti-grazing and anti-parasitic activities, and have a potentially strong structuring role for the dynamic of Alexandrium blooms. In many studies evaluating the effects of Alexandrium on marine organisms, only the classical toxins were reported and the involvement of BECs was not considered. A lack of information on the presence/absence of BECs in experimental strains is likely the cause of contrasting results in the literature that render impossible a distinction between PSTs and BECs effects. We review the knowledge on Alexandrium BEC, (i.e., producing species, target cells, physiological effects, detection methods and molecular candidates). Overall, we highlight the need to identify the nature of Alexandrium BECs and urge further research on the chemical interactions according to their ecological importance in the planktonic chemical warfare and due to their potential collateral damage to a wide range of organisms.

Description: The unprecedented challenge of reaching carbon neutrality before mid-century and a large share of it within 2030 in order to keep under the 1.5 or 2 °C carbon budgets, requires broad and deep changes in production and consumption patterns which, together with a shift to renewables and reinforced efficiency, need to be addressed through energy sufficiency. However, inadequate representations and obstacles to characterising and identifying sufficiency potentials often lead to an underrepresentation of sufficiency in models, scenarios and policies. One way to tackle this issue is to work on the development of sufficiency assumptions at a concrete level where various implications such as social consequences, environmental co-benefits, conditions for implementation can be discussed. This approach has been developed as the backbone of a collaborative project, gathering partners in 20 European countries at present, aiming for the integration of harmonised national scenarios into an ambitious net-zero European vision. The approach combines a qualitative discussion on the role of energy sufficiency in a "systemic" merit order for global sustainability, and a quantitative discussion of the level of sufficiency to be set to contribute to meeting 100 % renewables supply and net-zero emissions goals by 2050 at the latest. The latter is based on the use of a dashboard, which serves as a common descriptive framework for all national scenario trajectories and their comparison, with a view to harmonising and strengthening them through an iterative process. A set of key sufficiency-related indicators have been selected to be included in the dashboard, while various interrelated infrastructural, economic, environmental, social or legal factors or drivers have been identified and mapped. This paves the way for strengthening assumptions through the elaboration of "sufficiency corridors" defining a convergent, acceptable and sustainable level of energy services in Europe. The process will eventually inform the potential for sufficiency policies through a better identification of leverages, impacts and co-benefits.

Description: This paper examines the concept of maritime multi-use as a territorial/SPATIAL governance instrument for the enhancement of sustainable development in five EU sea basins. Multi-use (MU) is expected to enhance the productivity of blue economy sectors, as well as deliver additional socio-economic benefits related to the environmental and social dimensions of sustainable development. The paper provides a definition of maritime multi-use and identifies the multi-uses with the highest potential in EU sea basins. In each sea basin, multi-use plays a different role as concerns sustainable development. For the Eastern Baltic Sea, the Mediterranean Sea and the Black Sea, the MU focus should remain on the environmental pillar of sustainable development. In the North Sea, North Atlantic and Western Baltic Sea, addressing social sustainability seems a key precondition for success of MU in enhancement of sustainable spatial development at sea. Moreover, it has been suggested to introduce MU key global strategies such as SDGs or Macroregional strategies and action plans and to supplement maritime spatial planning with sectoral incentives and educational efforts as key vehicles supporting MU. The paper concludes by identifying aspects which, in order to inform maritime spatial planning and maritime governance regarding a more conscious application of the aforementioned concept, require further investigation. Key tasks are related to: more profound evaluation of performance of policies supporting MUs, researching the impact of MU on societal goals and on the MU costs and benefits, including external ones, and finally identifying the impact of MU on the development of various sectors and regions on land.

Description: Technological innovations in energy-intensive industries (EIIs) have traditionally emerged within the boundaries of a specific sector. Now that these industries are facing the challenges of deep decarbonisation and a significant reduction in greenhouse gas (GHG) emissions is expected to be achieved across sectors, cross-industry collaboration is becoming increasingly relevant for low-carbon innovation. Accessing knowledge and other resources from other industrial sectors as well as co-developing innovative concepts around industrial symbiosis can be mutually beneficial in the search for fossil-free feedstocks and emissions reductions. In order to harness the potential of this type of innovation, it is important to understand not only the technical innovations themselves, but in particular the non-technical influencing factors that can drive the successful implementation of cross-industry collaborative innovation projects. The scientific state of the art does not provide much insight into this particular area of research. Therefore, this paper builds on three separate strands of innovation theory (cross-industry innovation, low-carbon innovation and innovation in EIIs) and takes an explorative case-study approach to identify key influencing factors for cross-industry collaboration for low-carbon innovation in EIIs. For this purpose, a broad empirical database built within the European joint research project REINVENT is analysed. The results from this project provide deep insights into the dynamics of low-carbon innovation projects of selected EIIs. Furthermore, the paper draws on insights from the research project SCI4Climate.NRW. This project serves as the scientific competence centre for IN4Climate.NRW, a unique initiative formed by politicians, industry and science to promote, among other activities, cross-industry collaboration for the implementation of a climate-neutral industry in the German federal state of North Rhine-Westphalia (NRW). Based on the results of the case study analysis, five key influencing factors are identified that drive the implementation of cross-industry collaboration for low-carbon innovation in EIIs: Cross-industry innovation projects benefit from institutionalised cross-industry exchange and professional project management and coordination. Identifying opportunities for regional integration as well as the mitigation of financial risk can also foster collaboration. Lastly, clear political framework conditions across industrial sectors are a key driver.