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Posted on: August 3, 2020

Threatened By Rising Seas, Alaska Village Decides To Relocate ...

Sea ice and the Arctic coast | National Snow and Ice Data Center

Overview | Flooding and Erosion in Alaska | Encountering ...

Climate change prompts Shishmaref, Alaska, to vote for mainland ...



REFERENCE ARTICLEManaging Melting Permafrost: Protecting communities and ecosystems: April 23, 2019 Christopher Camitta, Duke University, Nicholas School of the Environment. [LINK]





  1. For years, the town of Iñupiat town of Shishmaref, located on a small barrier island off the coast of the Seward Peninsula in western Alaska, faced severe erosion, sometimes losing large areas of land to the Bering Strait during storms[1]. The melting of permafrost, the underground layer of soil that perpetually sits at sub-freezing temperatures in some polar and high-altitude climates, sped the rate at which the island’s shores collapsed [1]. In August of 2016, Shishmaref’s residents decided that the risks of remaining on a disappearing island were too great to ignore and voted 94-78 to move the entire community inland, away from where it had persisted for hundreds of years [2].
  2. Alaska is no stranger to permafrost melting, one of the most visible negative effects of climate change that can be found in the United States. By some estimates, permafrost underlies up to two-thirds of Alaska’s land area[3]. As permafrost melts, it loses its firmness, often collapsing homes and roads, as has been seen in permafrost-covered areas across the state.[4],[5]. These collapses have had particularly severe effects on Native Alaskan communities like Shishmaref [4,5].
  3. Globally, vast reservoirs of carbon are locked within permafrost, which releases methane, a greenhouse gas much more potent than carbon dioxide, when it melts[6]. The warming contribution of this methane has the potential to cause a feedback with devastating climatic consequences, in which permafrost that melts due to warmer temperatures also contributes to those temperatures by way of its methane releases[7].
  4. The scope of problems created by melting permafrost calls for an increase in federal funding for research efforts that can result in recommendations for maintenance of solid, stable, and frozen permafrost by way of management practices and support for residents that both protect communities and maintain the ecological productivity of land in Alaska.
  5. One example of current knowledge relates to the effects of off-road vehicles (ORVs, a category that includes both ATVs and large industrial equipment such as Caterpillar tractors) on permafrost[8]. A review conducted in 1990 discussed existing research that found increased melting associated with ORV usage in permafrost-covered areas and recommended mapping of particularly sensitive areas, training of ORV drivers, and regulations on where and how often ORVs can operate.
  6. Funding should be directed to evaluation of other human activities—potentially including logging and building construction—that affect permafrost integrity. On the community side, Shishmaref residents have expressed concerns that the state and federal governments will not assist them in their relocation. The federal government should work with communities affected by permafrost melting and the state of Alaska to ensure that these communities receive the help they need to either relocate or slow the destabilization of permafrost.
  7. Ultimately, due to the global ramifications of permafrost melting, the United States and Alaska have a responsibility to employ strategies to protect permafrost and provide research that can both benefit permafrost-underlain communities in other persistently cold climates as well as their own (such as in Siberia and northern Canada) and protect the carbon reservoirs held within the world’s frozen soil.




  1. The article appears to be a plea for research funding, a significant financial considerations for large universities in the USA that rely on research funding as a significant portion of their funding portfolio. The plea is based entirely on the the study of practical methods that can be employed to mitigate human activity that interacts directly with the permafrost to cause physical instability and thereby facilitate its erosion.
  2. In that respect, the research proposal identifies significant physical damage that can be caused by the use of large and heavy transport machinery used in sensitive areas where such machinery can physically destabilize the permafrost layer during the warm summer months. Specifically, the authors identify off-road vehicles (ORV), all terrain vehicles (ATV), and construction equipment such as large Caterpillar tractors.
  3. What appears to be a rational research proposal is then described as a study of the effect of the movement of these vehicles in sensitive areas in summer on the stability of the permafrost layer; and based on that data to propose restrictions on the movement of such vehicles in the identified sensitive permafrost areas of Alaska such as Shishmaref.
  4. This part of the research proposal appears to be entirely rational and something that should surely be funded. However, at this point, the authors, perhaps to gain access to climate change research funds, propose that the permafrost instability issue is a climate change issue because this instability is the creation of the fossil fuel emissions of the industrial economy in terms of global warming.
  5. There are two significant issues in this climate change attribution. First, anthropogenic global warming and climate change (AGW) is a theory about long term warming trends in global mean temperature. The interpretation of highly localized phenomena at brief time scales such as permafrost instability in Shishmaref, Alaska in the summer of 2020, in terms of AGW is not possible because of the internal variability issue in climate science described in a related post on this site [LINK] . Briefly, the internal variability issue is that only climate data that are global have an AGW interpretation and only at time scales of longer than 30 years. Therefore permafrost instability events such as the one in Shishmaref, that are both localized and time constrained to event rather than long term  trend, do not have an AGW interpretation.
  6. Yet another consideration is that the proposal contains the assumption but not the evidence that the observed permafrost instability is a creation of the human caused warming trend of the industrial economy. The literature review presented below does not support the view that the kind of permafrost instability seen in Shishmaref in the summer of 2020 is unique to the climate condition created by the post industrial economy human caused global warming. Such instability is a feature of the whole of the Holocene that is seen in the database as cycles of warming and cooling with the warming cycles going all the way back to the Holocene Optimum, exhibit significant permafrost instability and decay.
  7. In conclusion, we support the proposal for a research project that can formulate the needed rational restrictions on the movement of heavy vehicles and construction equipment known to cause permafrost instability and we hope that this research is funded, but we do not find evidence to support the idea that such instability is a creation of AGW.

Overview | Flooding and Erosion in Alaska | Encountering ...



  1. A large database of paleo climate data for the Arctic over the entire time span of the Holocene has been constructed by climate scientists with significant roles played by Hanna Sundqvist, Darrell Kaufman, Nicholas McKay and 18 other authors. The database is available for download at this site. Here is the link: ARCTIC-DATABASE .  Warning, clicking on this link will cause a very large PDF file to be downloaded. This database contains only the data and not their interpretation. For that we refer to the published papers about these data in the literature provided below in the bibliography.
  2. If you have a low opinion of climate scientists and their scientific integrity from your experience with things like the hockey stick, prepare to be surprised. The significant and chaotic cycles of warming and cooling in the Arctic for the whole of the Holocene in this database is consistent with the interpretation of these changes presented in a related post [LINK] such that periods with the Arctic warmer than AGW, colder than AGW, less ice than AGW, and more ice than AGW are all found in the database. In the context of the database, all we can say about the Arctic in the current warm period is that we are in the Holocene.



  1. Humlum, Ole. “Holocene permafrost aggradation in Svalbard.” Geological Society, London, Special Publications 242.1 (2005): 119-129.  The distribution and dynamics of permafrost represent a complex problem, confounded by a short research history and a limited number of deep vertical temperature profiles. This lack of knowledge is pronounced for the High Arctic, where most permafrost is found and where amplified responses to various climatic forcing mechanisms are expected. Within the High Arctic, the Svalbard region displays a unique climatic sensitivity and knowledge of Holocene, and modern permafrost dynamics in this region therefore have special interest. This paper reviews knowledge on Holocene permafrost development in Svalbard and the climatic background for this. In Svalbard, modern permafrost thickness ranges from less than 100 m near the coasts to more than 500 m in the highlands. Ground ice is present as rock glaciers, as ice-cored moraines, buried glacial ice, and in pingos and ice wedges in major valleys. Svalbard is characterized by ongoing local-scale twentieth-century permafrost aggradation, even though a distinct temperature increase around 1920 introduced relatively unfavourable climatic conditions for permafrost in Svalbard. Modern permafrost aggradation is to a large extent controlled by wind, solid precipitation and avalanche activity, and exemplifies the complexity of relating climate and permafrost dynamics.
  2. Kaufman, Darrell S., et al. “A multi-proxy record of the Last Glacial Maximum and last 14,500 years of paleoenvironmental change at Lone Spruce Pond, southwestern Alaska.” Journal of paleolimnology 48.1 (2012): 9-26.  Sediment cores from Lone Spruce Pond (60.007°N, 159.143°W), southwestern Alaska, record paleoenvironmental changes during the global Last Glacial Maximum (LGM), and during the last 14,500 calendar years BP (14.5 cal ka). We analyzed the abundance of organic matter, biogenic silica, carbon, and nitrogen, and the isotope ratios of C and N, magnetic susceptibility, and grain-size distribution of bulk sediment, abundance of alder shrub (Alnus) pollen, and midge (Chironomidae and Chaoboridae) assemblages in a 4.7-m-long sediment sequence from the depocenter at 22 m water depth. The basal unit contains macrofossils dating to 25–21 cal ka (the global LGM), and is interpreted as glacial-lacustrine sediment. The open water requires that the outlet of the Ahklun Mountain ice cap had retreated to within 6 km of the range crest. In addition to cladocerans and diatoms, the glacial-lacustrine mud contains chironomids consistent with deep, oligotrophic conditions; several taxa associated with relatively warm conditions are present, suggestive of relative warmth during the global LGM. The glacial-lacustrine unit is separated from the overlying non-glacial lake sediment by a possible disconformity, which might record a readvance of glacier ice. Non-glacial sediment began accumulating around 14.5 cal ka, with high flux of mineral matter and fluctuating physical and biological properties through the global deglacial period, including a reversal in biogenic-silica (BSi) content during the Younger Dryas (YD). During the global deglacial interval, the δ13C values of lake sediment were higher relative to other periods, consistent with low C:N ratios (8), and suggesting a dominant atmospheric CO2 source of C for phytoplankton. Concentrations of aquatic faunal remains (chironomids and Cladocera) were low throughout the deglacial interval, diversity was low and warm-indicator taxa were absent. Higher production and air temperatures are inferred following the YD, when bulk organic-matter (OM) content (LOI 550 °C) increased substantially and permanently, from 10 to 30 %, a trend paralleled by an increase in C and N abundance, an increase in C:N ratio (to about 12), and a decrease in δ13C of sediment. Post-YD warming is marked by a rapid shift in the midge assemblage. Between 8.9 and 8.5 cal ka, Alnus pollen tripled (25–75 %), followed by the near-tripling of BSi (7–19 %) by 8.2 cal ka, and δ15N began a steady rise, reflecting the buildup of N and an increase in denitrification in soils. Several chironomid taxa indicative of relatively warm conditions were present throughout the Holocene. Quantitative chironomid-based temperature inferences are complicated by the expansion of Alnus and resulting changes in lake nutrient status and production; these changes were associated with an abrupt increase in cladoceran abundance and persistent shift in the chironomid assemblage. During the last 2,000 years, chironomid-assemblage changes suggest cooler temperatures, and BSi and OM values were generally lower than their maximum Holocene values, with minima during the seventh and eighth centuries, and again during the eighteenth century.
  3. Sundqvist, Hanna S., et al. “Arctic Holocene proxy climate database–new approaches to assessing geochronological accuracy and encoding climate variables.” (2014).  We present a systematic compilation of previously published Holocene proxy climate records from the Arctic. We identified 170 sites from north of 58° N latitude where proxy time series extend back at least to 6 cal ka (all ages in this article are in calendar years before present – BP), are resolved at submillennial scale (at least one value every 400 ± 200 years) and have age models constrained by at least one age every 3000 years. In addition to conventional metadata for each proxy record (location, proxy type, reference), we include two novel parameters that add functionality to the database. First, “climate interpretation” is a series of fields that logically describe the specific climate variable(s) represented by the proxy record. It encodes the proxy–climate relation reported by authors of the original studies into a structured format to facilitate comparison with climate model outputs. Second, “geochronology accuracy score” (chron score) is a numerical rating that reflects the overall accuracy of 14C-based age models from lake and marine sediments. Chron scores were calculated using the original author-reported 14C ages, which are included in this database. The database contains 320 records (some sites include multiple records) from six regions covering the circumpolar Arctic: Fennoscandia is the most densely sampled region (31% of the records), whereas only five records from the Russian Arctic met the criteria for inclusion. The database contains proxy records from lake sediment (60%), marine sediment (32%), glacier ice (5%), and other sources. Most (61%) reflect temperature (mainly summer warmth) and are primarily based on pollen, chironomid, or diatom assemblages. Many (15%) reflect some aspect of hydroclimate as inferred from changes in stable isotopes, pollen and diatom assemblages, humification index in peat, and changes in equilibrium-line altitude of glaciers. This comprehensive database can be used in future studies to investigate the spatio-temporal pattern of Arctic Holocene climate changes and their causes. The Arctic Holocene data set is available from NOAA Paleoclimatology.
  4. Kaufman, Darrell S., et al. “Holocene climate changes in eastern Beringia (NW North America)–A systematic review of multi-proxy evidence.” Quaternary Science Reviews 147 (2016): 312-339.  Reconstructing climates of the past relies on a variety of evidence from a large number of sites to capture the varied features of climate and the spatial heterogeneity of climate change. This review summarizes available information from diverse Holocene paleoenvironmental records across eastern Beringia (Alaska, westernmost Canada and adjacent seas), and it quantifies the primary trends of temperature- and moisture-sensitive records based in part on midges, pollen, and biogeochemical indicators (compiled in the recently published Arctic Holocene database, and updated here to v2.1). The composite time series from these proxy records are compared with new summaries of mountain-glacier and lake-level fluctuations, terrestrial water-isotope records, sea-ice and sea-surface-temperature analyses, and peatland and thaw-lake initiation frequencies to clarify multi-centennial- to millennial-scale trends in Holocene climate change. To focus the synthesis, the paleo data are used to frame specific questions that can be addressed with simulations by Earth system models to investigate the causes and dynamics of past and future climate change. This systematic review shows that, during the early Holocene (11.7–8.2 ka; 1 ka = 1000 cal yr BP), rather than a prominent thermal maximum as suggested previously, temperatures were highly variable, at times both higher and lower than present (approximate mid-20th-century average), with no clear spatial pattern. Composited pollen, midge and other proxy records average out the variability and show the overall lowest summer and mean-annual temperatures across the study region during the earliest Holocene, followed by warming over the early Holocene. The sparse data available on early Holocene glaciation show that glaciers in southern Alaska were as extensive then as they were during the late Holocene. Early Holocene lake levels were low in interior Alaska, but moisture indicators show pronounced differences across the region. The highest frequency of both peatland and thaw-lake initiation ages also occurred during the early Holocene. During the middle Holocene (8.2–4.2 ka), glaciers retreated as the regional average temperature increased to a maximum between 7 and 5 ka, as reflected in most proxy types. Following the middle Holocene thermal maximum, temperatures decreased starting between 4 and 3 ka, signaling the onset of Neoglacial cooling. Glaciers in the Brooks and Alaska Ranges advanced to their maximum Holocene extent as lakes generally rose to modern levels. Temperature differences for averaged 500-year time steps typically ranged by 1–2 °C for individual records in the Arctic Holocene database, with a transition to a cooler late Holocene that was neither abrupt nor spatially coherent. The longest and highest-resolution terrestrial water isotope records previously interpreted to represent changes in the Aleutian low-pressure system around this time are here shown to be largely contradictory. Furthermore, there are too few records with sufficient resolution to identify sub-centennial-scale climate anomalies, such as the 8.2 ka event. The review concludes by suggesting some priorities for future paleoclimate research in the region.
  5. Briner, Jason P., et al. “Holocene climate change in Arctic Canada and Greenland.” Quaternary Science Reviews 147 (2016): 340-364.  This synthesis paper summarizes published proxy climate evidence showing the spatial and temporal pattern of climate change through the Holocene in Arctic Canada and Greenland. Our synthesis includes 47 records from a recently published database of highly resolved Holocene paleoclimate time series from the Arctic (Sundqvist et al., 2014). We analyze the temperature histories represented by the database and compare them with paleoclimate and environmental information from 54 additional published records, mostly from datasets that did not fit the selection criteria for the Arctic Holocene database. Combined, we review evidence from a variety of proxy archives including glaciers (ice cores and glacial geomorphology), lake sedimentspeat sequences, and coastal and deep-marine sediments. The temperature-sensitive records indicate more consistent and earlier Holocene warmth in the north and east, and a more diffuse and later Holocene thermal maximum in the south and west. Principal components analysis reveals two dominant Holocene trends, one with early Holocene warmth followed by cooling in the middle Holocene, the other with a broader period of warmth in the middle Holocene followed by cooling in the late Holocene. The temperature decrease from the warmest to the coolest portions of the Holocene is 3.0 ± 1.0 °C on average (n = 11 sites). The Greenland Ice Sheet retracted to its minimum extent between 5 and 3 ka, consistent with many sites from around Greenland depicting a switch from warm to cool conditions around that time. The spatial pattern of temperature change through the Holocene was likely driven by the decrease in northern latitude summer insolation through the Holocene, the varied influence of waning ice sheets in the early Holocene, and the variable influx of Atlantic Water into the study region.
  6. Badding, Michael E., Jason P. Briner, and Darrell S. Kaufman. “10Be ages of late Pleistocene deglaciation and Neoglaciation in the north‐central Brooks Range, Arctic Alaska.” Journal of Quaternary Science 28.1 (2013): 95-102.  We present a chronology of late Pleistocene deglaciation and Neoglaciation for two valleys in the north‐central Brooks Range, Alaska, using cosmogenic 10Be exposure dating. The two valleys show evidence of ice retreat from the northern range front before ∼16–15 ka, and into individual cirques by ∼14 ka. There is no evidence for a standstill or re‐advance during the Lateglacial period, indicating that a glacier advance during the Younger Dryas, if any, was less extensive than during the Neoglaciation. The maximum glacier expansion during the Neoglacial is delimited by moraines in two cirques separated by about 200 km and dated to 4.6 ± 0.5 and 2.7 ± 0.2 cal ka BP. Both moraine ages agree with previously published lichen‐inferred ages, and confirm that glaciers in the Brooks Range experienced multiple advances of similar magnitude throughout the late Holocene. The similar extent of glaciers during the middle Holocene and the Little Ice Age may imply that the effect of decreasing summer insolation was surpassed by increasing aridity to limit glacier growth as Neoglaciation progressed. Copyright © 2012 John Wiley & Sons, Ltd.

Climate change prompts Shishmaref, Alaska, to vote for mainland ...






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