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The science of extreme-event attribution has grown rapidly in an effort to quantify the extent to which climate change is altering the frequency or severity of extreme events and to [...]

Coastal archaeology is vulnerable to climate change, making the development of new techniques for the rapid recovery of information from the most threatened sites essential. The authors report a systematic kayak survey of a Chesapeake Bay sub-estuary undertaken during the winter months, when low tides and reduced vegetation maximise the visibility of archaeological material. Locations in the vulnerable intertidal zone were targeted for survey. Data were collected for 24 archaeological sites, illuminating local settlement chronology. This technique could be used for the survey of endangered coastal archaeology in other regions of the world. Keywords: North America, Chesapeake Bay, shell midden, heritage management, Introduction The consequences of twenty-first century climate change, including rising sea levels, rapid erosion and increased storm intensity, pose significant risks to coastal archaeological sites. The scale of this challenge [...]

Experimental studies assessing the potential impacts of ocean acidification on marine organisms have rapidly expanded and produced a wealth of empirical data over the past decade. This perspective examines four key areas of transformative developments in experimental approaches: (1) methodological advances; (2) advances in elucidating physiological and molecular mechanisms behind observed C[O.sub.2] effects; (3) recognition of short-term C[O.sub.2] variability as a likely modifier of species sensitivities (Ocean Variability Hypothesis); and (4) consensus on the multistressor nature of marine climate change where effect interactions are still challenging to anticipate. No single experiment allows predicting the fate of future populations. But sustaining the accumulation of empirical evidence is critical for more robust estimates of species reaction norms and thus for enabling better modeling approaches. Moreover, advanced experimental approaches are needed to address knowledge gaps including changes in species interactions and intraspecific variability in sensitivity and its importance for the adaptation potential of marine organisms to a high C[O.sub.2] world. Key words: Ocean Variability Hypothesis, ocean warming, acidification, oxygen decline. Les études expérimentales qui évaluent les impacts potentiels de l'acidification des océans sur les organismes marins ont rapidement pris de l'ampleur et produit une abondance de données empiriques au cours de la dernière décennie. Le présent article se penche sur quatre domaines clés d'avancées transformatives dans les approches expérimentales, à savoir : (1) les avancées méthodologiques, (2) les avancées dans l'élucidation des mécanismes physiologiques et moléculaires qui sous-tendent les effets observés du C[O.sub.2], (3) la reconnaissance de la variabilité à court terme du C[O.sub.2] comme modificateur probable de la sensibilité des espèces (hypothèse de la variabilité des océans) et (4) un consensus sur le fait que les changements climatiques marins sont source de différents facteurs de stress, de sorte qu'il demeure difficile d'anticiper les interactions d'effets. Aucune expérience ne permet à elle seule de prédire le destin de populations futures, mais il est d'importance capitale de poursuivre l'accumulation de preuves empiriques pour produire des estimations plus robustes des normes de réaction des espèces et ainsi permettre de meilleures approches de modélisation. Des approches expérimentales avancées sont en outre nécessaires pour combler des manques de connaissances notamment sur les modifications des interactions d'espèces et la variabilité intraspécifique de la sensibilité et son importance pour le potentiel d'adaptation d'organismes marins à un monde riche en C[O.sub.2]. [Traduit par la Rédaction] Mots-clés : hypothèse de la variabilité des océans, réchauffement des océans, acidification, appauvrissement en oxygène., The challenge of experimentally addressing marine climate change Anthropogenic climate change has been a scientific consensus for decades, but its reality is coming into ever sharper focus with each new [...]

Glaciers distinct from the Greenland and Antarctic ice sheets cover an area of approximately 706,000 square kilometres globally.sup.1, with an estimated total volume of 170,000 cubic kilometres, or 0.4 metres of potential sea-level-rise equivalent.sup.2. Retreating and thinning glaciers are icons of climate change.sup.3 and affect regional runoff.sup.4 as well as global sea level.sup.5,6. In past reports from the Intergovernmental Panel on Climate Change, estimates of changes in glacier mass were based on the multiplication of averaged or interpolated results from available observations of a few hundred glaciers by defined regional glacier areas.sup.7-10. For data-scarce regions, these results had to be complemented with estimates based on satellite altimetry and gravimetry.sup.11. These past approaches were challenged by the small number and heterogeneous spatiotemporal distribution of in situ measurement series and their often unknown ability to represent their respective mountain ranges, as well as by the spatial limitations of satellite altimetry (for which only point data are available) and gravimetry (with its coarse resolution). Here we use an extrapolation of glaciological and geodetic observations to show that glaciers contributed 27 [plus or minus] 22 millimetres to global mean sea-level rise from 1961 to 2016. Regional specific-mass-change rates for 2006-2016 range from -0.1 metres to -1.2 metres of water equivalent per year, resulting in a global sea-level contribution of 335 [plus or minus] 144 gigatonnes, or 0.92 [plus or minus] 0.39 millimetres, per year. Although statistical uncertainty ranges overlap, our conclusions suggest that glacier mass loss may be larger than previously reported.sup.11. The present glacier mass loss is equivalent to the sea-level contribution of the Greenland Ice Sheet.sup.12, clearly exceeds the loss from the Antarctic Ice Sheet.sup.13, and accounts for 25 to 30 per cent of the total observed sea-level rise.sup.14. Present mass-loss rates indicate that glaciers could almost disappear in some mountain ranges in this century, while heavily glacierized regions will continue to contribute to sea-level rise beyond 2100. The largest collection so far of glaciological and geodetic observations suggests that glaciers contributed about 27 millimetres to sea-level rise from 1961 to 2016, at rates of ice loss that could see the disappearance of many glaciers this century., Author(s): M. Zemp [sup.1] , M. Huss [sup.2] [sup.3] , E. Thibert [sup.4] , N. Eckert [sup.4] , R. McNabb [sup.5] , J. Huber [sup.1] , M. Barandun [sup.3] , [...]

Differences in habitat associations or responses to environmental stressors among broadly co-distributed species can result in local variation in community composition. As a result, ongoing environmental change may drive shifts in community composition, especially at range peripheries. In the present study, we describe regional variation in avian community composition at the southern extent of the boreal zone. Boreal bird communities are disproportionally influenced by ongoing climate change and contain several declining species. Here we observe the habitat associations for 13 boreal bird species, and assess the link between species' habitat associations and community composition. We conducted standardized point counts at 20 boreal forest sites in northeastern United States and Canada, and quantified the vegetation structure and composition as well as the climate at each site. We found large variation in the habitat associations among co-distributed boreal birds, both in terms of the specific variables important for each species and in the breadth of habitat types occupied. These findings suggest that species within this community will vary in their responses to environmental change, potentially resulting in changes to the boreal avian community. Received 19 October 2017. Accepted 9 October 2018. Key words: community structure, habitat ordination, range limits, range periphery, spruce-fir forest birds. (French)--Les differences cntre les associations d'habitat ou les rcponses aux facteurs de stress environnementaux parmi les especes qui sont largement co-reparties pcuvent conduit des variations locales dans la composition de la communaute. En consequence, les changements environnementaux pourraient influencer des changements dans la composition de la communaute. en particulier aux peripheries des aires de repartitions. Dans cette etude, nous decrivons la variation regionale de la composition des communautes aviaircs a l'etendue sud de la zone boreale. Les communautes d'oiseaux boreaux sont influencees plus disproportionnement par le changement climatique et comiennent plusieurs d'especes en declin. Nous observons ici les associations d'habitat pour 13 especes d'oiseaux boreaux et evaluons le lien entre les associations d'habitat des especes et la composition de la communaute. Au moyen de comptages standardisees d'oiseaux a 20 sites dans la foret boreale d'Amerique du Nord (le nord-est des Etats-Unis et du Canada), nous quantifiames la structure et la composition de la vegetation a chaque site ainsi que le climat. Parmi les associations d'habitat. nous trouvames beaucoup de variation cntre les oiseaux qui sont co-reparties dans la foret boreale, a la fois en tcrmes de variables specifiques importantes pour chaque espece et la largeur des types d'habitat occupes. Ces resultats suggerent que les especes dans cette communaute varieront en reponse aux les changements environnementaux, entrainant potentiellement aux changements dans la communaute d'oiseaux boreaux. Mots-cles: limitcs de 1'aire de repartition, oiseaux de la foret pessiere, ordination de 1'habitat, peripheric de l'aire de repartition, structure de la communaute., The relationship between species-specific patterns of habitat use and the composition of biotic communities is at the heart of ecological biogeography. The explorer-naturalists of the early- and mid-19th century recognized [...]

INTRODUCTION. In March-July 2017, northeast China suffered a long period of intense hot and dry weather. This concurrent heat and drought extreme event affected more than 7.4 x [10.sup.5] [km.sup.2] [...]

ABSTRACT This paper describes the Stratospheric Aerosol Geoengineering Large Ensemble (GLENS) project, which promotes the use of a unique model dataset, performed with the Community Earth System Model, with the [...]

The depths of the ocean are a giant melting pot. Look anywhere and you'll find a bit of water from everywhere. How can seawater be from anywhere? Well, like French [...]

I was about fifteen minutes into my nap when I heard the announcement: 'Polar bear. Port beam. One hundred yards. Huge.' I paused to consider: Would this be worth losing [...]

The cold, wet climate of the Arctic has led to the extraordinary preservation of archaeological sites and materials that offer important contributions to the understanding of our common cultural and ecological history. This potential, however, is quickly disappearing due to climate-related variables, including the intensification of permafrost thaw and coastal erosion, which are damaging and destroying a wide range of cultural and environmental archives around the Arctic. In providing an overview of the most important effects of climate change in this region and on archaeological sites, the authors propose the next generation of research and response strategies, and suggest how to capitalise on existing successful connections among research communities and between researchers and the public. Keywords: Arctic, climate change, conservation, heritage management, archaeological mitigation strategies, Introduction The past decade has witnessed growing global concern about the accelerating impact of climate change on archaeological sites (Colette 2007; see online supplementary material (OSM) 1, references 1-4). An [...]

INTRODUCTION CLIMATE CHANGE AMPLIFICATION in the Arctic is increasing the impacts on both terrestrial and aquatic systems in northern regions (Serreze and Barry, 2011; Vincent et al., 2011). The impacts [...]

INTRODUCTION CLIMATE CHANGE IS CONSIDERED ONE OF the greatest potential threats to global biodiversity (Thomas et al2004). Currently, it is altering the distribution and abundance of numerous species (Parmesan, 2006), [...]

ABSTRACT.--Wanning temperatures have been linked to advancing spring migration dates of birds, although most studies have been conducted at individual sites. Problems may arise ecologically if birds arrive or depart [...]

Author(s): F. Alexander Haumann (corresponding author) [1, 2]; Nicolas Gruber [1, 2]; Matthias Mnnich [1]; Ivy Frenger [1, 3]; Stefan Kern [4] Recent salinity changes in the Southern Ocean [1, [...]

Author(s): David R. Legates[sup.1] Author Affiliations: David R. Legates is professor of climatology in the College of Earth, Ocean, and Environment, University of Delaware, Newark, DE 19716; legates@udel.edu. He has [...]

The effect of temperature on predator-prey dynamics has the potential to be an important factor regulating ecological interactions and is becoming increasingly common due to climate-change-driven range shifts and species introductions. Here, we use mesocosm experiments to evaluate the thermal sensitivity of burst swimming (a proxy for prey escape ability) and mortality rates of cohorts of introduced tropical and resident temperate marine fishes in the presence of a local temperate predator. Increasing temperature (17-21-25 °C) resulted in a reduction in predation rates (by Hypoplectrodes maccullochi, family Serranidae) on the tropical prey species (Abudefduf vaigiensis, family Pomacentridae) which were more warm adapted, whereas predation rates on the temperate prey species (Atypichthys strigatus, family Kyphosidae) remained unchanged over the 17-21 °C range (25 °C not tested). These changes were linearly related to predator-prey burst swimming ratios, which decreased with increasing temperature for the tropical prey but remained largely unchanged for the temperate prey. By demonstrating the temperature sensitivity of predator-prey interactions, our work highlights the importance of linking physiology with ecology to understand the consequences of climate-driven range shifts and species introductions., Author(s): Will F. Figueira [sup.1] , Belinda Curley [sup.2] , David J. Booth [sup.3] Author Affiliations: (Aff1) 0000 0004 1936 834X, grid.1013.3, School of Life and Environmental Sciences, University of [...]

The paper addresses the evaluation of climate models and gives an overview of epistemic uncertainties in climate modeling; the uncertainties concern the data situation as well as the causal behavior of the climate system. In order to achieve reasonable results nonetheless, multimodel ensemble studies are employed in which diverse models simulate the future climate under different emission scenarios. The models jointly deliver a robust range of climate prognoses due to a broad plurality of theories, techniques, and methods in climate research; the range reliably indicates the future development of the global climate. Nevertheless, the uncertainties are widely used by skeptics to challenge the IPCC's prognoses. Such skeptical allegations can well be distinguished from points of fruitful epistemological criticism: in spite of the enduring range of prognoses, the epistemic uncertainties should not play a role in finding agreements on climate change mitigation., Author(s): Anna Leuschner[sup.1] Author Affiliations: (1) Karlsruher Institut für Technologie, ITAS, Karlsruhe, Germany Introduction In climate research, statements on climate change, including those by the Intergovernmental Panel on Climate Change [...]

In this paper I argue that the appropriate analogy for 'understanding what makes simulation results reliable' in global climate modeling is not with scientific experimentation or measurement, but-at least in the case of the use of global climate models for policy development-with the applications of science in applied design problems. The prospects for using this analogy to argue for the quantitative reliability of GCMs are assessed and compared with other potential strategies., Author(s): William M. Goodwin[sup.1] Author Affiliations: (1) College of Arts and Sciences, University of South Florida, 33620, Tampa, FL, USA Introduction The use of global climate models to design policies [...]

ABSTRACT. Sediment cores from three lakes located in the northernmost region of Ungava, Quebec (Canada) were examined to define aquatic community and ecosystem variability during the Late Holocene period. A [...]

The ice field of Mount Kilimanjaro, the highest peak of Africa, was made famous by Ernest Hemingway in 'The Snows of Kilimanjaro.' Scientific evidence shows that the snows of Kilimanjaro [...]