Description: One of the consequences of warming climate is rising ground temperatures and degradation of perennially frozen ground, permafrost. Thawing of near-surface permafrost can cause geohazards, such as ground subsidence, thaw settlement and thermokarst, potentially harmful to nature and human activity in the Arctic. This dataset contains high-resolution raster grids of near-future permafrost extent and geohazard potential for the Northern Hemisphere permafrost areas. Ground temperature was predicted with statistical models employing geospatial data on environmental conditions at 30 arc-second resolution (~1 km2). These predictions, together with data on factors affecting permafrost stability, were used to formulate geohazard indices. Using climate-forcing scenarios (Representative Concentration Pathways 2.6, 4.5 and 8.5), permafrost extent and hazard potential were projected for the 2041–2060 and 2061–2080 time periods. The resulting dataset consists of seven permafrost (extent during 2000–2014 and the six future scenarios) and 24 geohazard maps in GeoTIFF format.

Description: This dataset contains spatial predictions of the potential environmental spaces for pingos, ice-wedge polygons and rock glaciers across the Northern Hemisphere permafrost areas. The potential environmental spaces, i.e. conditions where climate, topography and soil properties are suitable for landform presence, were predicted with statistical ensemble modelling employing geospatial data on environmental conditions at 30 arc-second resolution (~1 km). In addition to the baseline period (1950-2000), the predictions are provided for 2041-2060 and 2061-2080 using climate-forcing scenarios (Representative Concentration Pathways 4.5 and 8.5). The resulting dataset consists of five spatial predictions for each landform in GeoTIFF format. The data provide new information on 1) the fine-scale spatial distribution of permafrost landforms in the Northern Hemisphere, 2) the potential future alterations in the environmental suitability for permafrost landforms due to climate change, and 3) the circumpolar distribution of various ground ice types, and can 4) facilitate efforts to inventory permafrost landforms in incompletely mapped areas.

Description: The presence of ground ice in Arctic soils exerts a major effect on permafrost hydrology and ecology, and factors prominently into geomorphic landform development. As most ground ice has accumulated in near-surface permafrost, it is sensitive to variations in atmospheric conditions. Typical and regionally widespread permafrost landforms such as pingos, ice-wedge polygons, and rock glaciers are closely tied to ground ice. However, under ongoing climate change, suitable environmental spaces for preserving landforms associated with ice-rich permafrost may be rapidly disappearing. We deploy a statistical ensemble approach to model, for the first time, the current and potential future environmental conditions of three typical permafrost landforms, pingos, ice-wedge polygons and rock glaciers across the Northern Hemisphere. We show that by midcentury, the landforms are projected to lose more than one-fifth of their suitable environments under a moderate climate scenario (RCP4.5) and on average around one-third under a very high baseline emission scenario (RCP8.5), even when projected new suitable areas for occurrence are considered. By 2061–2080, on average more than 50% of the recent suitable conditions can be lost (RCP8.5). In the case of pingos and ice-wedge polygons, geographical changes are mainly attributed to alterations in thawing-season precipitation and air temperatures. Rock glaciers show air temperature-induced regional changes in suitable conditions strongly constrained by topography and soil properties. The predicted losses could have important implications for Arctic hydrology, geo- and biodiversity, and to the global climate system through changes in biogeochemical cycles governed by the geomorphology of permafrost landscapes. Moreover, our projections provide insights into the circumpolar distribution of various ground ice types and help inventory permafrost landforms in unmapped regions.

Description: Ground ice dynamics bear crucial importance in the hydrologic and ecologic development of permafrost landscapes, but also create characteristic landforms. So far, spatial distributions and sensitivities of these landforms under changing climates have not been assessed at a circumpolar scale. We integrated pingo (n = 9,709), ice-wedge polygon (n = 861) and rock glacier (n = 4,035) observations and geospatial data on environmental conditions into a statistical modelling framework to produce high-resolution (~1km2) distribution maps of permafrost landform occurrence across the Northern Hemisphere in current and future climates. We found that on average more than one-fifth of the potential environmental spaces might be lost by mid-century under a moderate human-induced greenhouse emission forcing (representative concentration pathway, RCP4.5). Thereon, environmental spaces continue to shrink to less than 50% of the current coverage by 2061–2080, given a ‘business-as-usual’ (RPC8.5) climate-forcing scenario. Forecasted losses of suitable regions for pingos and ice-wedge polygons were attributed to increases in precipitation and thawing-season air temperatures. Rock glaciers were dominantly air temperature-driven. Our results are congruent with the site- and regional-scale observations of rapid geomorphic responses to ongoing climate change, and for the first time demonstrate large regional shifts in potential landform distributions at a circumpolar scale. These findings suggest that extensive regions are undergoing drastic changes in Earth surface processes, e.g. ground ice thaw, which are prone to cause thermokarst and threats to infrastructure development. Despite sophisticated modelling frameworks and increased data availability, circumpolar-scale geomorphological distribution modelling is still highly dependent on the quality of used geospatial data and the completeness of sampling, especially in heterogeneous environments. Based on the magnitude of climatic sensitivities of permafrost landforms, we suggest that geomorphic responses should be closely integrated into assessments of climate change impacts on natural and human systems.

Description: Fish are known for their high phenotypic plasticity in life-history traits in relation to environmental variability, and this is particularly pronounced among salmonids in the Northern Hemisphere. Resource limitation leads to trade-offs in phenotypic plasticity between life-history traits related to the reproduction, growth, and survival of individual fish, which have consequences for the age and size distributions of populations, as well as their dynamics and productivity. We studied the effect of plasticity in growth and fecundity of vendace females on their reproductive traits using a series of long-term incubation experiments. The wild parental fish originated from four separate populations with markedly different densities, and hence naturally induced differences in their growth and fecundity. The energy allocation to somatic tissues and eggs prior to spawning served as a proxy for total resource availability to individual females, and its effects on offspring survival and growth were analyzed. Vendace females allocated a rather constant proportion of available energy to eggs (per body mass) despite different growth patterns depending on the total resources in the different lakes; investment into eggs thus dictated the share remaining for growth. The energy allocation to eggs per mass was higher in young than in old spawners and the egg size and the relative fecundity differed between them: Young females produced more and smaller eggs and larvae than old spawners. In contrast to earlier observations of salmonids, a shortage of maternal food resources did not increase offspring size and survival. Vendace females in sparse populations with ample resources and high growth produced larger eggs and larvae. Vendace accommodate strong population fluctuations by their high plasticity in growth and fecundity, which affect their offspring size and consequently their recruitment and productivity, and account for their persistence and resilience in the face of high fishing mortality. The density-dependent growth of vendace influences egg production and recruitment of offspring and regulates the variability observed in many vendace populations. These small-sized schooling fish compensate strong population fluctuations by their extreme plasticity in growth and fecundity, which affect their offspring size and consequently their productivity, and account for their persistence and resilience in the face of high fishing mortality. The variability in body size of short-lived pelagic schooling fish under different environmental and nutritional conditions is exceptional among vertebrates, and a special feature is also their capability to keep the relative fecundity constant regardless of high interannual fluctuation in their food resources per capita. Thus, the basis for the ecologically sustainable use for the populations of these commercially important species with dense schools is in many ways different compared to several other exploited species with later maturation, long life cycle, and different social structure of the population.