Impacts of permafrost degradation on infrastructure

The warming and thawing of ice-rich permafrost pose considerable threat to the integrity of polar and high-altitude infrastructure, in turn jeopardizing sustainable development. In this Review, we explore the extent and costs of observed and predicted infrastructure damage associated with permafrost degradation, and the methods available to mitigate such adverse consequences. Permafrost change imposes various threats to infrastructure, namely through warming, active layer thickening and thaw-related hazards such as thermokarst and mass wasting.These impacts, often linked to anthropogenic warming, are exacerbated through increased human activity. Observed infrastructure damage is substantial, with up to 80% of buildings in some Russian cities and -30% of some road surfaces in the Qinghai-Tibet Plateau reporting damage. Under anthropogenic warming, infrastructure damage is projected to continue, with 30-50% of critical circumpolar infrastructure thought to be at high risk by 2050. Accordingly, permafrost degradation-related infrastructure costs could rise to tens of billions of US dollars by the second half of the century. Several mitigation techniques exist to alleviate these impacts, including convection embankments, thermosyphons and piling foundations, with proven success at preserving and cooling permafrost and stabilizing infrastructure. To be effective, however, better understanding is needed on the regions at high risk.Peer reviewe

Permafrost hydrology in changing climatic conditions: seasonal variability of stable isotope composition in rivers in discontinuous permafrost

Role of changing climatic conditions on permafrost degradation and hydrology was investigated in the transition zone between the tundra and forest ecotones at the boundary of continuous and discontinuous permafrost of the lower Yenisei River. Three watersheds of various sizes were chosen to represent the characteristics of the regional landscape conditions. Samples of river flow, precipitation, snow cover, and permafrost ground ice were collected over the watersheds to determine isotopic composition of potential sources of water in a river flow over a two year period. Increases in air temperature over the last forty years have resulted in permafrost degradation and a decrease in the seasonal frost which is evident from soil temperature measurements, permafrost and active-layer monitoring, and analysis of satellite imagery. The lowering of the permafrost table has led to an increased storage capacity of permafrost affected soils and a higher contribution of ground water to river discharge during winter months. A progressive decrease in the thickness of the layer of seasonal freezing allows more water storage and pathways for water during the winter low period making winter discharge dependent on the timing and amount of late summer precipitation. There is a substantial seasonal variability of stable isotopic composition of river flow. Spring flooding corresponds to the isotopic composition of snow cover prior to the snowmelt. Isotopic composition of river flow during the summer period follows the variability of precipitation in smaller creeks, while the water flow of larger watersheds is influenced by the secondary evaporation of water temporarily stored in thermokarst lakes and bogs. Late summer precipitation determines the isotopic composition of texture ice within the active layer in tundra landscapes and the seasonal freezing layer in forested landscapes as well as the composition of the water flow during winter months

Sustaining permafrost observations: priorities and needs of the Global Terrestrial Network for Permafrost (GTN-P)

The Global Terrestrial Network for Permafrost (GTN-P) is the primary international programme concerned with sustained long-term monitoring of permafrost. GTN-P was developed in the 1990s by the International Permafrost Association (IPA) under the Global Terrestrial Observing System (GTOS) as part of the Global Climate Observing System (GCOS). The two major components of GTN-P (Essential Climate Variables) are: (a) long-term monitoring of the thermal state of permafrost in an extensive borehole network, the Thermal State of Permafrost - TSP; and (b) monitoring of the Active-layer thickness - ALT. Long-term monitoring of permafrost generates essential baseline information for the assessment of climate change impacts in polar and high mountain regions

Changes in the 1963–2013 shallow ground thermal regime in Russian permafrost regions

Spatial variability and temporal trends of the shallow ground thermal regime and permafrost active-layer thickness (ALT) were estimated over 1963–2013 using daily soil temperature data available from stations of the Russian Hydrometeorological Service. Correlation analysis was used to evaluate the role of changing climatic conditions on the ground thermal regime. ALT data collected by the Circumpolar Active Layer Monitoring program in Russia were used to expand the geography of ALT observations over 1999–2013, and to identify ‘hot spots’ of soil temperature and ALT change. Results indicate that a substantially higher rate of change in the thermal regime of permafrost-affected soils prevailed during 1999–2013, relative to the last fifty years. Results indicate that the thermal regime of the upper permafrost in western Russia is strongly associated with air temperature, with much weaker relationships in central and eastern Russia. The thermal regime of permafrost-affected soils shows stronger dependence on climatic conditions over the last fifteen years relative to the historical 50-year period. Geostatistical analysis revealed that the cities of Norilsk and Susuman are hot spots of permafrost degradation. Of six settlements selected for detailed analysis in various parts of the permafrost regions, all but one (Chukotka), show substantial changes in the shallow ground thermal regime. Northern locations in the continuous permafrost region show thickening of the active layer, while those farther south experienced development of residual thaw layers above the permafrost and decreases in the duration of the freezing period

GTN-P - Strategy and Implementation Plan 2016-2020

Permafrost is recognized as Essential Climate Variable (ECV) within the Global Climate Observing System of UN and ICSU organisations. The Global Terrestrial Network for Permafrost (GTN-P) is the primary international programme concerned with long-term monitoring of permafrost. The core mission of the GTN-P is sustained comprehensive long-term monitoring network, in order to provide consistent, representative and high quality standardized long-term data series of selected permafrost parameters at key sites and to assess their state and changes over time. The Strategy and Implementation Plan 2016-2020 outlines recent progress and future challenges facing the network. It describes the governance and management structure of GTN-P, linkages to regional and global observing systems, management process and reporting strategies. It presents measurement methods and protocols used in field data collection and state of the art data management system, which was recently designed and implemented to process, analyse, and visualize permafrost data. It concludes with the outlook of the future developments of the network in order to sustain and succeed its core mission of providing long-term observations and maintain the availability of data collected

GTN-P borehole data management towards global assessment of permafrost temperature change

In 1999, the International Permafrost Association (IPA) established the Global Terrestrial Network for Permafrost (GTN-P, gtnp.org). The goal of the network is systematic and long-term documentation of the distribution, variability, and trends of permafrost (an Essential Climate Variable, ECV) based on a global network of field measurements. The two current cryospheric indicators are permafrost temperature and active layer thickness, throughout the Earth’s permafrost regions. The network has been mainly operated by scientist and research institutions and programs. GTN-P developed a Data Management System (gtnpdatabase.org) for the collection, processing (including standardisation), and dissemination of permafrost data and metadata. Recent ground temperature and active layer thickness data are being compiled to provide an update to the current permafrost state. GTN-P is part of the Global Climate Observing System (GCOS) Global Terrestrial Observing System (GTOS). GCOS is a joint undertaking of the World Meteorological Organization (WMO), the Intergovernmental Oceanographic Commission (IOC) of the United Nations Educational Scientific and Cultural Organization (UNESCO), the United Nations Environment Programme (UNEP) and the International Council for Science (ICSU). Permafrost temperature measurements, commonly performed with permanently installed multi-thermistor cables in boreholes, enable a good accuracy of 0.1°C. The logger resolution and measurement frequency, however, varies with the type and the depth of the individual borehole. Due to high geomorphological surface and subground dynamics, the relative vertical position of testing probes can change and bias the depth indications of old boreholes in sensitive areas. Most important quality concerns are measurement accuracy, zero annual amplitude depth, data gaps, incomplete time series, and spatial clustering of boreholes. We developed a methodological approach to filter the data by defined quality rules in order to calculate global to regional weighted averages of permafrost temperature anomalies. In this presentation we aim to give an overview on the systematical data pathway from borehole principal investigators over National Correspondents in GTN-P, followed by data processing algorithms in the GTN-P DMS towards quality checked time series data

Permafrost is warming at a global scale

Permafrost warming has the potential to amplify global climate change, because when frozen sediments thaw it unlocks soil organic carbon. Yet to date, no globally consistent assessment of permafrost temperature change has been compiled. Here we use a global data set of permafrost temperature time series from the Global Terrestrial Network for Permafrost to evaluate temperature change across permafrost regions for the period since the International Polar Year (2007-2009). During the reference decade between 2007 and 2016, ground temperature near the depth of zero annual amplitude in the continuous permafrost zone increased by 0.39 ± 0.15 °C. Over the same period, discontinuous permafrost warmed by 0.20 ± 0.10 °C. Permafrost in mountains warmed by 0.19 ± 0.05 °C and in Antarctica by 0.37 ± 0.10 °C. Globally, permafrost temperature increased by 0.29 ± 0.12 °C. The observed trend follows the Arctic amplification of air temperature increase in the Northern Hemisphere. In the discontinuous zone, however, ground warming occurred due to increased snow thickness while air temperature remained statistically unchanged