Inuit hunters and meteorologists alike pay close attention to weather and weather changes, with deep understandings. This paper describes a long-time research project based in Kangiqtugaapik (Clyde River), Nunavut, where a research team of Inuit and visiting scientists have combined information and knowledge from a community-based weather station network, on-going interviews and discussions, and extensive travel (both Arctic fieldwork and visits to southern universities) to co-produce knowledge related to human–weather relationships and weather information needs and uses in one Nunavut community. The project uses the concept of “HREVs”, human-relevant environmental variables — complex, synthesis variables that, used in conjunction with a host of social variables, assist in informing safe land travel and activities. This work, including linking Inuit knowledge and environmental modeling, can be expanded to not only understand human–weather relationships more broadly and in other locations but also provide insights into the process of building diverse research teams and knowledge co-production. Inuit angunasuktiit amma silalirijiit tamarmik ujjiqsuttiasuunguvut silamit amma silaup asijjiqpallianingani, tukisiumaniqarjuaqłutik. Una paippaangujuq unikkaarivuq akuniujumi qaujitasaqtaunirmut piliriangujumi Kangiqtugaapik (Clyde River), Nunavummi, qaujisaqtiujuni katinngajuni Inungni amma pularaqtunut qaujisaqtiujunut katirisimajuni uqausiksani amma qaujimaniujumi nunalingni−tunngavilingmi silalirivvingmi tusaumatittiniujumi, apiqsuqtaunginnaqtuni amma uqallangniujuni, amma aullaaqsimarjuaqłutik (tamakkit Ukiuqtaqtumi iniujumi piliriniujumi amma pulararniujunut qallunaat nunanganni silattuqsarvigjuangujunut) saqqitittiqatigiingnirmut qaujimaniujumi pijjutiqaqtumut inungnut−silamut piliriqatigiingniujuni amma silamut uqausiksani pijariaqarniujunut amma aturniujunut atausirmi Nunavummi nunaliujumi. Piliriangujuq atusuunguvuq isumagijauniujumi “HREVs”, inungnut-atuutilingnut avatimut ajjigiinnginniujunut – nalunaqtuni, katinniujuni isumagijauniujuni aaqqiksinirnut piliri−jusiujumi ajjigiinnginniujuni, atuqatiqaqłuni ilagijaujumi inuuqatigiingujunut ajjigiinnginniujunit, ikajuqsuisuunguvuq aaqqiksuinirmi attananngittumi nunami aullaarniujumi amma qanuiliurniujunut. Una piliriniujuq ilaqaqtumi kasuqatiqarnirmi inuit qaujimajanginni amma avatimut uukturautiqarnirmi, angigligiaqtaujunnaqpuq tukisiumanituangunngittumi inungt-silamut piliriqatigiingniujumi tauvunngaujjiniujumi ammalu asinginni iniujunut, kisiani tunisijunnaqpuq tukisirjuarniujuni piliriniujuni sananirmut ajjigiinngiruluujaqtuni qaujisaqtiujunut katinngajuni amma qaujimanirmut saqqitittiqatigiingniujumi.

Climate change affects Arctic marine ecosystems, the ecosystem services they provide, and the human well-being that relies on these services. The impacts of climate change in the Arctic and elsewhere involve cascading effects and feedbacks that flow across social-ecological systems (SES), such as when sea ice loss alters food security through changes in the distribution of marine animals. These cascades and feedbacks across social and ecological systems can exacerbate the effects of climate change or lead to surprising outcomes. Identifying where cascades and feedbacks may occur in SES can help anticipate, or even prevent unexpected outcomes of climate change, and lead to improved policy responses. Here, we perform a systematic literature review of multidisciplinary Arctic research to determine the state of knowledge of the impacts of climate change on marine ecosystems. Then, in a case study corresponding to Inuit regions, we use network analysis to integrate research into a SES perspective and identify which linkages have been most versus least studied, and whether some potential cascades and feedbacks have been overlooked. Finally, we propose ways forward to advance knowledge of changing Arctic marine SES, including transdisciplinary approaches involving multiple disciplines and the collaboration of Indigenous and local knowledge holders.

Climate in high latitude environments is predicted to undergo a pronounced warming and increase in precipitation, which may influence the terrestrial moisture gradients that affect vegetation distribution. Vegetation cover can influence rates of greenhouse gas production through differences in microbial communities, plant carbon uptake potential, and root transport of gases out of the soil into the atmosphere. To predict future changes in greenhouse gas production from High Arctic ecosystems in response to climate change, it is important to understand the interaction between trace gas fluxes and vegetation cover. During the growing seasons of 2008 and 2009, we used dark static chambers to measure CH4 and N2O fluxes and CO2 emissions at Cape Bounty, Melville Island, NU, across a soil moisture gradient, as reflected by their vegetation cover. In both years, wet sedge had the highest rates of emission for all trace gases, followed by the mesic tundra ecosystem. CH4 consumption was highest in the polar semi-desert, correlating positively with temperature and negatively with moisture. Our findings demonstrate that net CH4 uptake may be largely underestimated across the Arctic due to sampling bias towards wetlands. Overall, greenhouse gas flux responses vary depending on different environmental drivers, and the role of vegetation cover needs to be considered in predicting the trajectory of greenhouse gas uptake and release in response to a changing climate.

The overall spatial and temporal influence of shrub expansion on permafrost is largely unknown due to uncertainty in estimating the magnitude of many counteracting processes. For example, shrubs shade the ground during the snow-free season, which can reduce active layer thickness. At the same time, shrubs advance the timing of snowmelt when they protrude through the snow surface, thereby exposing the active layer to thawing earlier in spring. Here, we compare 3056 in situ frost table depth measurements split between mineral earth hummocks and organic inter-hummock zones across four dominant shrub–tundra vegetation types. Snow-free date, snow depth, hummock development, topography, and vegetation cover were compared to frost table depth measurements using a structural equation modeling approach that quantifies the direct and combined interacting influence of these variables. Areas of birch shrubs became snow free earlier regardless of snow depth or hillslope aspect because they protruded through the snow surface, leading to deeper hummock frost table depths. Projected increases in shrub height and extent combined with projected decreases in snowfall would lead to increased shrub protrusion across the Arctic, potentially deepening the active layer in areas where shrub protrusion advances the snow-free date.

Resource development in Arctic waters is proceeding rapidly leading to increased interactions with Arctic wildlife. As sea ice extent decreases, the demand for shipping and ice-breaking operations will expand into winter and spring with greater impact on ice-dependent pinnipeds. However, knowledge of the distribution of these species, such as ringed seals (Pusa hispida (Schreber, 1775)), during spring within areas of resource development is lacking. Baffinland Iron Mines Corporation’s Mary River iron ore port in southern Milne Inlet, Nunavut opened in 2015 with proposed ice-breaking activities in spring — an important period in ringed seal seasonal life-history. We conducted infrared and photographic aerial surveys in June 2016 and 2017 to overlay the proposed ice-breaking route with ringed seal hotspots (i.e., areas of higher density). We identified four areas of overlap where proposed ice-breaking would traverse through ringed seal hotspots: eastern and western Eclipse Sound (a ringed seal pupping ground identified by local knowledge), the middle of Milne Inlet, and southern Milne Inlet. We identified potential negative implications of spring ice-breaking operations on ringed seals such as displacement, separation of mothers and pups, destruction of resting and birth lairs, and vessel–seal collisions. Results are relevant to policy decision-makers who can develop mitigation strategies in the rapidly melting and developing Arctic.

Permafrost thaw, tundra shrubification, and changes in snow cover properties are documented impacts of climate warming, particularly in subarctic regions where discontinuous permafrost is disappearing. To obtain some insight into those changes, permafrost, active layer thickness, vegetation, snow cover, ground temperature, soil profiles, and carbon content were surveyed in an integrated approach in six field plots along a chronosequence of permafrost thaw on an ice-rich silty soil. Historical air photographs and dendrochronology provided the chronological context. Comparison of the plots reveals a positive feedback effect between thaw settlement, increased snow cover thickness, shrub growth, increase in soil temperature, and the process of permafrost decay. By the end of the sequence permafrost was no longer sustainable. Along the estimated 90 year duration of the chronosequence, the originally centimeter-thin pedogenic horizons under mosses and lichens increased to a thickness of nearly 65 cm under shrubs and trees. Snow cover increased from negligible to over 2 m. The thickness of soil organic layers and soil organic matter content increased manyfold, likely a result of the increased productivity in the shrub-dominated landscape. The results of this study strongly suggest that permafrost ecosystems in the subarctic are being replaced under climate warming by shrub and forest ecosystems enriched in carbon on more evolved soils.

Climate warming is projected to alter the vegetation community composition of arctic and alpine ecosystems including an increase in the relative abundance and cover of deciduous shrubs. This change in plant functional group dominance will likely alter tundra ecosystem structure and function. We conducted an observational study to quantify how the understory vegetation community and ecosystem properties varied along a shrub density and altitudinal gradient in a tundra alpine ecosystem in south-west Yukon. Although there was weak association between shrub density and species richness of understory community, there were large differences in functional group abundance between the different shrub densities; forb cover increased at lower elevations with higher shrub density at the expense of cryptogam and dwarf shrub cover. Litter mass, light interception, and soil carbon:nitrogen ratios all increased with shrub density. Sites with shrubs had higher summer soil temperatures, lower summer soil moisture, and lower percent soil nitrogen than the shrub-free site, although there was no difference in available nutrients among sites. This study presents findings from a nonmanipulated, model system where shrubification has been documented and suggests that direct and indirect effects of increasing shrub dominance are likely to affect the surrounding vegetation and abiotic environment controls.

Water temperature measurements (2004–2016) from two small rivers in the High Arctic were analyzed to determine the effects of climate variability on thermal regime and the sensitivity to climate change. The East and West rivers (unofficial names) drain similar watersheds (11.6 and 8.0 km2, respectively) and are located at the Cape Bounty Arctic Watershed Observatory (CBAWO), Melville Island, Canada (74°55′N, 109°35′W). Differences in seasonal timing of river temperatures were evident when comparing the coldest and warmest years of the study period, and across different discharge conditions. Snowmelt runoff is characterized by uniformly cold water (∼0–1 °C) over a wide range of discharge conditions, followed by warming water temperatures during flow recession. The rivers showed varying sensitivity to mid-summer air temperature conditions in a given year, with warmer years indicating high correlation (r2 = 0.794–0.929), whereas colder years showed reduced correlation (r2 = 0.368–0.778). River temperatures reached levels which are reported to negatively affect fish and other cold-water aquatic species (>18 °C) with greater frequency and duration during the warmest years. These results provide a basis to further enhance prediction of river thermal conditions to assess ecosystem health in a river system and to refine insights into the effects of climate change on High Arctic aquatic ecosystems.

Conserving Arctic wildlife will be challenging given the ongoing environmental changes in the region. In addition, there is a lack of fundamental biological information for many Arctic species, including a dearth of knowledge surrounding conservation threats and the risk of extinction. In this study, we gather all available data on research effort and life-history traits to assess the current state of scientific knowledge surrounding 389 Arctic vertebrate species. We also quantify patterns of species evaluation by the IUCN Red List, a global database of conservation risk used to measure success and prioritize resources in many conservation programs. We find that 10% of Arctic vertebrates have been the subject of no peer-reviewed studies during the last 30 years, and that we have little life history knowledge for many species. Arctic marine fishes are especially poorly known with an average of 3.5 (out of six) key life-history traits unknown. In a multivariate analysis, whether an Arctic species had been evaluated by the IUCN Red List was most strongly predicted by research effort and varied among taxonomic groups. In addition, we found that species that have been evaluated by the IUCN Red List continue to receive more research attention than species which have not been evaluated. Protecting all Arctic species may, therefore, require research programs and methods to halt research inertia and shift more attention onto species that are poorly known.