Permafrost is defined as ground (soil or rock and included ice or organic matter) that remains at or below 0°C for at least two consecutive years.
In the Northern Hemisphere, approximately 25% (23 million km²) of the land area contains permafrost. Most of the permafrost existing today formed during cold glacial periods, and has persisted through warmer interglacial periods, including the Holocene. The Holocene is a geological epoch which began approximately 11,700 years ago (last 10,000 years). Some relatively shallow permafrost (30 to 70 meters) formed during the second part of the Holocene (last 6,000 years) and some during the Little Ice Age (from 400 to 150 years ago). The thickness of permafrost varies from less than one meter to more than 1500 meters.
Subsea and offshore permafrost is permafrost overlain by a marine water column. Most submarine permafrost occurs in the Arctic, is relict terrestrial permafrost, and has been degrading since being inundated during sea level rise after the Last Glacial Maximum. Submarine permafrost can contain ice, depending on its temperature, salt content, sediment grain size, and composition.
While important to coastal communities and offshore processes and infrastructure, permafrosts also role in the global carbon cycle. Large amounts of fossil organic carbon and greenhouse gases are trapped in the frozen permafrost, which in turn, if released to the atmosphere, may increase global warming.
Nuntaryuk will quantify the fluxes and fates of organic matter released from thawing coastal and subsea permafrost and assess what risks thawing coastal permafrost poses to infrastructure, indigenous and local communities and people’s health. The project will use this understanding to estimate the long-term impacts of permafrost thaw to the Arctic coastal regions, global climate and the economy.
Although land and subsea permafrost contains vast carbon stocks, it is currently either not represented at all in Earth System Models, or limited to a one-dimensional description of the land permafrost without lateral exchange. Nunataryuk will move beyond this one dimensional representation of permafrost thaw to characterize resulting lateral fluxes, thus linking land to coast to ocean. Nunataryuk will also be the first EU program ever to target the more vulnerable subsea permafrost and assess its potential for abrupt methane releases to the atmosphere. Subsea permafrost, in particular, is a potentially important compotent for the Earth System Models, but so far, the data basis for its inclusion in the Models has been missing. Both sub-permafrost and intra-permafrost carbon stocks, whether in the form of buried vegetation/soil or as preformed greenhouse gas, are poorly constrained, in terms of distribution, amount and source.
Three aspects are central to this effort, all of which involve a data gathering and research component, and a modelling component.
- First, lateral mobilization of carbon will be analyzed and included into an Earth System Modelling framework, extending model capability beyond oversimplified land-only one-dimensional treatment. Nunataryuk will link specific impacts of permafrost thaw, setting carbon in motion, to its consequence for coastal and offshore systems, and effects at the global scale.
- Secondly, Nunataryuk will quantify arctic coastal erosion, currently undergoing dramatic change in order to provide global models with fluxes of dissolved organic carbon and nutrients to the arctic shelf seas. This aspect of the project, in particular, promises to lead to insights as to how arctic shelf ecosystems, which are critical to food security in the north, will react to change.
- Thirdly, Nunataryuk will deliver a public database with the first pan-arctic estimates of subsea permafrost distribution and of the carbon stock in the shelf sediment system. Subsea permafrost will be parameterized and modelled, its thaw integrated into the Earth System Modelling framework along with improved estimates of carbon stocks and their transformation beneath the arctic seas at the circum-arctic scale. A product of this effort is the first ever map of subsea permafrost combining modelling and available validation data. Together, these changes represent a great coordinated step forward in our understanding of permafrost as a single phenomenon that spans the coastal zone.
On the way to this end result, for the first time, subsea permafrost ans pan-arctic coastal fluxes will be integrated into an Earth System Model and be coupled to the overlying ocean. As a result, we will be able to project permafrost changes and their consequences until 2300, for the first time including permafrost in its entirety from land to coast to ocean and coupled to the capacity to calculate the societal costs of mitigation.
On the social science side, Nunataryuk will examine the consequences of permafrost thaw for epidemiology, contaminants, and human and animal health. Nunataryuk shows the links between permafrost change and health for the first time via identification of risks associated with increased thaw. Health is challenged by rapid environmental and societal change in the Arctic: high mortality rates from accidents, spreading infectious and vector-borne diseases, such as tick-borne encephalitis and Lyme disease (Revich et al, 2012) and mobilization of toxic substances due to permafrost thaw are the results. For example, frequent outbreaks of anthrax in the 19th century Arctic left viable spores in the permafrost. Thawing and rapid release poses a serious threat to the animal and human populations (Revich and Podolnaya, 2011). Risk for humans is assumed to depend on prevalence in the animal population, environmental contamination and contact patterns between humans, environment and animals (Morris and Blackburn 2016). Mathematical models of anthrax do not explicitly account for an external, possibly climate-driven, source of spores nor consider space explicitly. Nunataryuk aims at filling these gaps and developing a spatially explicit model to study the risk of anthrax outbreaks induced by permafrost thawing. Compounding these risks are threats to food and water security, as well as community infrastructure (Parkinson et al, 2014). Nunataryuk’s holistic approach integrates environmental and human health in understanding and responding to the health of Arctic residents. Based on scenarios of future environmental change, Nunataryuk will estimate the effects of these changes on human health risks of the populations living in coastal regions of the Arctic.
Infrastructure: Nunataryuk adopts a dual approach to studying that conducts knowledge building while also creating tools for tackling challenges faced by coastal communities confronted with challenges related to permafrost thaw. Overall, practical and rational recommendations are not available to decision-makers for assessing risks relating to existing and planned coastal infrastructure in an uncertain and changing climate with thawing permafrost. Simple tools are to some extent available to identify/quantify the vulnerability of specific infrastructure constructions. However, innovative thermal and mechanical numerical models are needed to properly describe the relevant processes for coastal infrastructure, such as increased coastal erosion and increased water transport in unsaturated and ice-rich permafrost soils. Nunataryuk moves beyond evaluating the vulnerability of individual infrastructures to recommendations for evaluating the vulnerability of infrastructure systems at the community scales. Nunataryuk produces new inventories of existing coastal infrastructure and its state, and develops data-aggregation algorithms and models that provide failure-probabilities (quantitatively or qualitatively) at the required scales. Through consultations and co-design, the proposed project responds to community-identified needs and generates output that integrates state of the art science, consultation, and scenarios of future change but is designed for use by local authorities.
Nunataryuk will link the applied research chain from co-design of knowledge creation using on-the- ground field research and community engagement to actionable policy engagement. Within permafrost science, extremely effective tools have been developed for the dissemination of research results, such as the GTN-P, and for the engagement of next generation researchers, such as Permafrost Young Researchers Network (PYRN). Nonetheless, a gap remains between physical science and people living on permafrost. Nunataryuk aims to bridge this gap. Integral to the project is the integration of northern residents, including indigenous people, in the project’s management structure, both on the Scientific Advisory Board and through the Stakeholder Forum. The epistemological ambition of Nunataryuk is to conduct truly transdisciplinary science, coupled to stakeholder interests. As such, the results of Nunataryuk’s natural science research, focused on permafrost from land to coast to ocean, have a designed relevance to stakeholders.
A chronic challenge for transdisciplinary science is the lack of a common language for physical and social scientists. Nunataryuk brings leading researchers from these research communities together in equal weight and defines mechanisms for two-way knowledge exchange between them. These mechanisms include the integration of knowledge from both communities in a common numerical Earth System Modelling framework, the inclusion of physical scientists in community-level engagement, and a focus on transdisciplinary issues such as human and animal health and community infrastructure. One tool produced by this combination of physical and social science knowledge is an innovative set of indicators for change.
The suite of Arctic social indicators developed and tested in the Arctic Social Indicators (ASI I and II) projects includes indicators for 6 domain areas that reflect prominent features of human development in the Arctic. These domains include Health; Education; Material Wellbeing; Cultural Wellbeing; Closeness to Nature; and Fate Control (ASI, 2010, 2015). Hence, the current set of indicators for long-term tracking of human development only treats social issues. A critical gap in knowledge exists in the development of a monitoring framework that incorporates both social and biophysical considerations. Nunataryuk will recommend action to community decision makers for adaptation and mitigation within the context of estimates of the costs of mitigation based on an Integrated Assessment Modelling approach, taking state of the art methodology to the next level of integration between physical science and socio- economic understanding.
While physical scientists study the environmental consequences of thawing permafrost, the impacts must be assessed in a way that integrates the physical, biological, social, economic and cultural dimensions of permafrost thaw. Nunataryuk, together with stakeholders, will develop tools to reduce local risks related to thawing permafrost, including estimates of the economic costs at the community level of projected future sea level rise and permafrost thaw. To ensure that its legacy is relevant to the next generation and carried forward into the future, Nunataryuk’s socio-economic analysis will focus on young people’s perception of opportunities and challenges arising from the rapid changes taking place in Arctic societies and most important how they see their role in mitigating risks and supporting community development.