ALBERT

Description: The spatial pattern of Antarctic surface air temperature variability on multi–decadal to multi–centennial time scales is poorly known because of the short instrumental records, the relatively small number of high–resolution paleoclimate observations, and biases in climate models. Here, changes in surface air temperature over Antarctica are reconstructed over the past two millennia using data assimilation constrained by different ice core water isotope records in order to identify robust signals. The comparison between previous statistically based temperature reconstructions and simulations covering the full Common Era driven by natural and anthropogenic forcings shows major discrepancies occurring in the period 1–1000 CE over East Antarctica, with the reconstructions displaying a warming over 1–500 CE that is not reproduced by the simulations. This suggests that the trends in the first millennium deduced from the statistically based reconstructions are unlikely to be entirely forced by external forcings. Our reconstructions show the high sensitivity of the 500-year temperature trend in Antarctica and its spatial distribution to selection of the records for the reconstructions, especially during 1–500 CE. A robust cooling over Antarctica during 501–1000 CE has been obtained in three data assimilation–based reconstructions with a larger magnitude in the WAIS than elsewhere over Antarctica, in agreement with previous estimates with the larger changes than simulated in climate models. The reconstructions for atmospheric circulation indicate that the pattern of temperature changes over 501–1000 CE is related to the positive trend of Southern Annular Mode and a deepening of Amundsen Sea Low. This confirms the role of internal variability in the temperature trends on multi–centennial scales.

Description: Extreme rainfall generated by storms and atmospheric instability causes innumerable damage to coastal areas and their marine ecosystems. This chapter describes some of the processes that generate critical precipitation events in coastal areas. Among these, the typical synoptic conditions combine with the increase in sea surface temperature and air temperature, coastal geomorphology, and sea breeze. Coastal and regional rainfall events should be studied to understand the meteorological, oceanographic, and geomorphological conditions that cause the extreme events, to later relate them with the consequences on coasts. The effects of the interaction of storms with tides originating storm surges and the effect of sea-level rise are described as well as the main consequences of extreme rainfall events such as beach erosion, decrease in water quality, changes in plankton and fish species that inhabit coastal waters, among others.

Description: The Arctic is greatly impacted by climate change. The increase in air temperature drives the thawing of permafrost and an increase in coastal erosion and river discharge. This leads to a greater input of sediment and organic matter into coastal waters, which substantially impacts the ecosystems by reducing light transmission through the water column and altering the biogeochemistry, but also the subsistence economy of local people, and changes in climate because of the transformation of organic matter into greenhouse gases. Yet, the quantification of suspended sediment in Arctic coastal and nearshore waters remains unsatisfactory due to the absence of dedicated algorithms to resolve the high loads occurring in the close vicinity of the shoreline. In this study we present the Arctic Nearshore Turbidity Algorithm (ANTA), the first reflectance-turbidity relationship specifically targeted towards Arctic nearshore waters that is tuned with in-situ measurements from the nearshore waters of Herschel Island Qikiqtaruk in the western Canadian Arctic. A semi-empirical model was calibrated for several relevant sensors in ocean color remote sensing, including MODIS, Sentinel 3 (OLCI), Landsat 8 (OLI), and Sentinel 2 (MSI), as well as the older Landsat sensors TM and ETM+. The ANTA performed better with Landsat 8 than with Sentinel 2 and Sentinel 3. The application of the ANTA to Sentinel 2 imagery that matches in-situ turbidity samples taken in Adventfjorden, Svalbard, shows transferability to nearshore areas beyond Herschel Island Qikiqtaruk.

Description: Recent demands by developing countries, like India, that developed countries need to reach net-negative emissions, must be negotiated seriously under the UNFCCC. Failure to acknowledge that limiting global average temperature rise to 1.5°C leaves very little carbon budget for equitable redistribution risks further ambiguity on how to achieve the Paris Agreement’s goals.

Description: Marine Neurotoxins, Volume Five provides comprehensive information on marine toxins present in the human food chain and the affecting targets relevant for the functioning of the brain and our nervous system, covering all the information ...

Description: Declaration of interest was missed out in the published version. The authors have confirmed in the following context: ‘The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.’ The publisher would like to apologise for any inconvenience caused.

Description: Understanding the multidimensionality of microplastics is essential for a realistic assessment of the risks these particles pose to the environment and human health. Here, we capture size, shape, area, polymer, volume and mass characteristics of 〉60,000 individual microplastic particles as continuous distributions. Particles originate from samples taken from different aquatic compartments, including surface water and sediments from the marine and freshwater environment, waste water effluents, and freshwater organisms. Data were obtained using state-of-the-art FTIR-imaging, using the same automated imaging post-processing software. We introduce a workflow with two quality criteria that assure minimum data quality loss due to volumetric and filter area subsampling. We find that probability density functions (PDFs) for particle length follow power law distributions, with median slopes ranging from 2.2 for marine surface water to 3.1 for biota samples, and that these slopes were compartment-specific. Polymer-specific PDFs for particle length demonstrated significant differences in slopes among polymers, hinting at polymer specific sources, removal or fragmentation processes. Furthermore, we provide PDFs for particle width, width to length ratio, area, specific surface area, volume and mass distributions and propose how these can represent the full diversity of toxicologically relevant dose metrics required for the assessment of microplastic risks.

Description: The current focus on mangroves as key ecosystems in mitigating the impacts of climate change has largely neglected the livelihoods of coastal dwellers interacting with mangroves. This article provides a review of scholarly and policy attention paid to these social groups and their means of struggle. It argues that the latest dominant governance discourse tying mangroves to blue carbon signifies a departure from catering to coastal people's interests and rights in mangroves. We describe the evolving discourses that have shaped mangrove use and conservation in the Philippines since the 1970s. While the mid-century preoccupation with mangrove conversion to fish farms gradually gave way to the pursuit of community-based mangrove conservation in the late 1980s and 1990s, recent experiences suggest a comparably weakened focus towards recognizing local access and use patterns. We contend that the present blue carbon framing of mangroves, which harbours technocratic and financialized ideals of sustainability, poses a fundamental disadvantage to local users of mangroves. We conclude by reflecting on ways to redress this trend via a new framing of mangroves.

Description: Agricultural extension is booming. This interest is critical in the context of numerous pressing issues linked to agrarian change and rural development. Because of its importance, extension has attracted significant critique for its persistent exclusion of social and political factors. In this light, the history of extension can be thought of as a paradigm composed of approaches aimed at increasing agricultural production through the transfer of technologies from experts to farmers, and a series of criticisms of technology transfer as hampered by neglect of socio-political factors, a process labelled ‘rendering technical’. By reviewing criticisms of extension for its rendering of socio-political factors, we account for the rendering of power, place, and people. Equally important, we offer examples that consolidate critiques in order to open the possibility that humanized extension may more successfully support farmers. Our review is an effort to engage extensionists in order to speak about power to those who attempt to speak truth to power.

Description: Highlights: • Ecological impacts of Pontogammarus maeoticus increased with temperature • Salinity effects were non-significant across temperatures (14–2 ppt; 18–22 °C) • Gammarids displayed hyperbolic Type II functional responses in all treatments • Future salinity regime shifts will not lessen ecological impacts via predation • Warming will heighten the ecological impacts of this emerging invasive species Abstract: Biological invasions are a growing ecological and socioeconomic problem worldwide. While robust predictions of impactful future invaders are urgently needed, understandings of invader impacts have been challenged by context-dependencies. In aquatic systems in particular, future climate change could alter the impacts of invasive non-native species. Widespread warming coupled with sea freshening may exacerbate ecological impacts of invaders in marine environments, compromising ecosystem structure, function and stability. We examined how multiple abiotic changes affect the potential ecological impact of an emerging invasive non-native species from the Ponto-Caspian region — a notorious origin hotspot for invaders, characterised by high salinity and temperature variation. Using a comparative functional response (feeding rates across prey densities) approach, the potential ecological impacts of the gammarid Pontogammarus maeoticus towards native chironomid prey were examined across a range of current and future temperature (18, 22°C) and salinity (14, 10, 6, 2 ppt) regimes in a factorial design. Feeding rates of P. maeoticus on prey significantly increased with temperature (by 60 %), but were not significantly affected by salinity regime. Gammarids displayed significant Type II functional responses, with attack rates not significantly affected by warming across all salinities. Handling times were, however, shortened by warming, and thus maximum feeding rates significantly increased, irrespective of salinity regime. Functional responses were significantly different following warming at high prey densities under all salinities, except under the ambient 10 ppt. Euryhalinity of invasive non-native species from the Ponto-Caspian region thus could allow sustained ecological impacts across a range of salinity regimes. These results corroborate high invasion success and field impacts of Ponto-Caspian gammarids in brackish through to freshwater ecosystems. Climate warming will likely worsen the potential ecological impact of P. maeoticus. With invasions growing worldwide, quantifications of how combined elements of climate change will alter the impacts of emerging invasive non-native species are needed.