#Catastrophic #effects of #climatechange on #children’s #health start before #birth (J Clin Invest., summary)

[Source: Journal of Clinical Investigation, full page: (LINK). Summary, edited.]

Catastrophic effects of climate change on children’s health start before birth

Susan E. Pacheco

First published January 13, 2020

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When I first paid attention to the magnitude of the climate crisis in 2006, it was hard to accept that I had been indifferent to the problem for so many years. As a pediatrician, it did not take long to realize that children, whose bodies and minds are still developing and who are dependent on adults for care, are the most tragic casualties of the climate crisis. The shift in weather patterns, increased heat, heat waves, and drought; the resulting wildfires, increased storm intensity and flooding, crop failure and lower nutritional value, and shifting pattern of infectious vectors; and the resulting air pollution from continued use of fossil fuels impose a heavy burden in children, whose inherent physical and emotional immaturity makes them more vulnerable to these insults.

(…)

Keywords: Climate change; Global Warming; Pediatrics.

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#Global #warming threatens #human #thermoregulation and #survival (J Clin Invest., summary)

[Source: Journal of Clinical Investigation, full page: (LINK). Summary, edited.]

Global warming threatens human thermoregulation and survival

Rexford S. Ahima

First published January 6, 2020

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There is overwhelming evidence showing that human activities have contributed to global warming over the past century. Global warming has a severe impact on food and water supplies, housing and other infrastructure, health, and economic activities. The human body has thermoregulatory mechanisms that adapt to ambient temperature and maintain normal core body temperature for physiological functions. This JCI Viewpoint article discusses how extreme temperatures driven by global warming disrupt normal thermoregulation and imperil human health and survival.

(…)

Keywords: Climate change; Global Warming; Infectious diseases.

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#Climatechange brings the #specter of new #infectious diseases (J Clin Invest., summary)

[Source: Journal of Clinical Investigation, full page: (LINK). Summary, edited.]

Climate change brings the specter of new infectious diseases

Arturo Casadevall

First published January 6, 2020

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Climate change will bring major changes to the epidemiology of infectious diseases through changes in microbial and vector geographic range. Human defenses against microbial diseases rely on advanced immunity that includes innate and adaptive arms and endothermy, which creates a thermal restriction zone for many microbes. Given that microbes can adapt to higher temperatures, there is concern that global warming will select for microbes with higher heat tolerance that can defeat our endothermy defenses and bring new infectious disease.

(…)

Keywords: Climate Change; Global Warming; Infectious Diseases.

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A quantitative #comparison of #WNV #incidence from 2013 to 2018 in Emilia-Romagna, #Italy (PLOS Negl Trop Dis., abstract)

[Source: PLOS Neglected Tropical Diseases, full page: (LINK). Abstract, edited.]

OPEN ACCESS /  PEER-REVIEWED / RESEARCH ARTICLE

A quantitative comparison of West Nile virus incidence from 2013 to 2018 in Emilia-Romagna, Italy

Giovanni Marini , Mattia Calzolari, Paola Angelini, Romeo Bellini, Silvia Bellini, Luca Bolzoni, Deborah Torri, Francesco Defilippo, Ilaria Dorigatti, Birgit Nikolay, Andrea Pugliese, Roberto Rosà, Marco Tamba

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Published: January 2, 2020 / DOI: https://doi.org/10.1371/journal.pntd.0007953

 

Abstract

Background

West Nile virus (WNV) transmission was much greater in 2018 than in previous seasons in Europe. Focusing on Emilia-Romagna region (northern Italy), we analyzed detailed entomological and epidemiological data collected in 2013–2018 to quantitatively assess environmental drivers of transmission and explore hypotheses to better understand why the 2018 epidemiological season was substantially different than the previous seasons. In particular, in 2018 WNV was detected at least two weeks before the observed circulation in 2013–2017 and in a larger number of mosquito pools. Transmission resulted in 100 neuroinvasive human cases in the region, more than the total number of cases recorded between 2013 and 2017.

Methodology

We used temperature-driven mathematical models calibrated through a Bayesian approach to simulate mosquito population dynamics and WNV infection rates in the avian population. We then estimated the human transmission risk as the probability, for a person living in the study area, of being bitten by an infectious mosquito in a given week. Finally, we translated such risk into reported WNV human infections.

Principal findings

The estimated prevalence of WNV in the mosquito and avian populations were significantly higher in 2018 with respect to 2013–2017 seasons, especially in the eastern part of the region. Furthermore, peak avian prevalence was estimated to have occurred earlier, corresponding to a steeper decline towards the end of summer. The high mosquito prevalence resulted in a much greater predicted risk for human transmission in 2018, which was estimated to be up to eight times higher than previous seasons. We hypothesized, on the basis of our modelling results, that such greater WNV circulation might be partially explained by exceptionally high spring temperatures, which have likely helped to amplify WNV transmission at the beginning of the 2018 season.

 

Author summary

West Nile virus (WNV) is one of the most recent emerging mosquito-borne diseases in Europe and North America. While most human infections are asymptomatic, about 1% of them can result in severe neurological diseases which might be fatal. WNV transmission was unusually greater in 2018 than in previous years in many European countries, resulting in a large number of human infections. Focusing on Emilia-Romagna region (Italy), we developed an epidemiological model informed by entomological data; through that we found that exceptionally high spring temperatures might have contributed at amplifying WNV transmission at the beginning of the season, causing greater WNV prevalence in mosquito and avian populations during the summer, which resulted in a higher estimated risk for human transmission. Thus, weather anomalies at the beginning of the mosquito breeding season, which are likely to become more common under the projected scenarios of climate change, might act as an early warning signal for public health authorities, enabling them to design efficient surveillance and prevention strategies.

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Citation: Marini G, Calzolari M, Angelini P, Bellini R, Bellini S, Bolzoni L, et al. (2020) A quantitative comparison of West Nile virus incidence from 2013 to 2018 in Emilia-Romagna, Italy. PLoS Negl Trop Dis 14(1): e0007953. https://doi.org/10.1371/journal.pntd.0007953

Editor: Waleed Saleh Al-Salem, Saudi Ministry of Health, SAUDI ARABIA

Received: July 10, 2019; Accepted: November 20, 2019; Published: January 2, 2020

Copyright: © 2020 Marini et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the manuscript and its Supporting Information files.

Funding: Data used in this study was collected in the frame of “Regional Surveillance of Arboviral Diseases” financed by the Emilia-Romagna Region. I.D. acknowledges research funding from the Imperial College Junior Research Fellowship and joint Centre funding from the UK Medical Research Council and Department for International Development. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Keywords: WNV; Wild Birds; Mosquitoes; Global Warming; Italy.

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#Disappearance of the last #tropical #glaciers in the Western Pacific Warm Pool (#Papua, #Indonesia) appears imminent (Proc Natl Acad Sci USA, abstract)

[Source: Proceedings of the National Academy of Sciences of the United States of America, full page: (LINK). Abstract, edited.]

Disappearance of the last tropical glaciers in the Western Pacific Warm Pool (Papua, Indonesia) appears imminent

Donaldi S. Permana, Lonnie G. Thompson, Ellen Mosley-Thompson, Mary E. Davis, Ping-Nan Lin, Julien P. Nicolas, John F. Bolzan, Broxton W. Bird, Vladimir N. Mikhalenko, Paolo Gabrielli, Victor Zagorodnov, Keith R. Mountain, Ulrich Schotterer, Wido Hanggoro, Muhammad N. Habibie, Yohanes Kaize, Dodo Gunawan, Gesang Setyadi, Raden D. Susanto, Alfonso Fernández, and Bryan G. Mark

PNAS first published December 9, 2019 / DOI: https://doi.org/10.1073/pnas.1822037116

Edited by Michael L. Bender, Princeton University, Princeton, NJ, and approved November 5, 2019 (received for review December 27, 2018)

 

Significance

The glaciers near Puncak Jaya, Papua, Indonesia, the last tropical glaciers in the Western Pacific Warm Pool, have recently undergone a rapid pace of loss of ice cover and a 5.4-fold increase in the rate of thinning, augmented by the strong 2015–2016 El Niño. Ice cores recovered in 2010 record approximately the past half-century of tropical Pacific climate variability and reveal the effects of El Niño–Southern Oscillation (ENSO). It appears that the regional warming has passed a threshold such that the next very strong ENSO event, which typically exacerbates the rising freezing levels and associated feedbacks such as reduced snow cover, could lead to the demise of the only remaining tropical glaciers between the Himalayas and the Andes.

 

Abstract

The glaciers near Puncak Jaya in Papua, Indonesia, the highest peak between the Himalayas and the Andes, are the last remaining tropical glaciers in the West Pacific Warm Pool (WPWP). Here, we report the recent, rapid retreat of the glaciers near Puncak Jaya by quantifying the loss of ice coverage and reduction of ice thickness over the last 8 y. Photographs and measurements of a 30-m accumulation stake anchored to bedrock on the summit of one of these glaciers document a rapid pace in the loss of ice cover and a ∼5.4-fold increase in the thinning rate, which was augmented by the strong 2015–2016 El Niño. At the current rate of ice loss, these glaciers will likely disappear within the next decade. To further understand the mechanisms driving the observed retreat of these glaciers, 2 ∼32-m-long ice cores to bedrock recovered in mid-2010 are used to reconstruct the tropical Pacific climate variability over approximately the past half-century on a quasi-interannual timescale. The ice core oxygen isotopic ratios show a significant positive linear trend since 1964 CE (0.018 ± 0.008‰ per year; P < 0.03) and also suggest that the glaciers’ retreat is augmented by El Niño–Southern Oscillation processes, such as convection and warming of the atmosphere and sea surface. These Papua glaciers provide the only tropical records of ice core-derived climate variability for the WPWP.

glacier retreat – tropical ice cores – Papua Indonesia – climate change – ENSO

 

Footnotes

1 To whom correspondence may be addressed. Email: donaldi.permana@bmkg.go.id or thompson.3@osu.edu.

Author contributions: L.G.T., E.M.-T., and R.D.S. designed research; D.S.P., L.G.T., E.M.-T., M.E.D., P.-N.L., B.W.B., V.N.M., P.G., V.Z., K.R.M., W.H., M.N.H., Y.K., D.G., G.S., and R.D.S. performed research; D.S.P., L.G.T., M.E.D., P.-N.L., J.P.N., J.F.B., U.S., A.F., and B.G.M. analyzed data; D.S.P., L.G.T., E.M.-T., and M.E.D. wrote the paper; D.S.P., L.G.T., V.N.M., P.G., V.Z., K.R.M., W.H., Y.K., D.G., G.S., and R.D.S. supported the ice core drilling project and collected ice core samples; D.S.P., L.G.T., K.R.M., W.H., M.N.H., Y.K., and G.S. measured the stake accumulation; M.E.D., and P.-N.L. conducted the ice core stable isotope, dust, and chemical analyses; and U.S. conducted the ice core tritium analysis.

The authors declare no competing interest.

This article is a PNAS Direct Submission.

Data deposition: The data reported in this paper have been archived at the National Center for Environmental Information (NCEI) National Oceanic and Atmospheric Administration (NOAA) World Data Center for Paleoclimatology: https://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/ice-core; https://www.ncdc.noaa.gov/paleo/study/24351.

This article contains supporting information online at https://www.pnas.org/lookup/suppl/doi:10.1073/pnas.1822037116/-/DCSupplemental.

Published under the PNAS license.

.

Keywords: Climate Change; Global Warmings; Indonesia.

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The 2019 #report of The Lancet #Countdown on #health and #climatechange: ensuring that the health of a #child born today is not defined by a changing climate (Lancet, summary)

[Source: The Lancet, full page: (LINK). Summary, edited.]

The 2019 report of The Lancet Countdown on health and climate change: ensuring that the health of a child born today is not defined by a changing climate

Nick Watts, MA, Markus Amann, PhD, Prof Nigel Arnell, PhD, Sonja Ayeb-Karlsson, PhD, Kristine Belesova, PhD, Prof Maxwell Boykoff, PhD et al.

Published: November 13, 2019 / DOI: https://doi.org/10.1016/S0140-6736(19)32596-6

 

Summary

The Lancet Countdown is an international, multidisciplinary collaboration, dedicated to monitoring the evolving health profile of climate change, and providing an independent assessment of the delivery of commitments made by governments worldwide under the Paris Agreement.

Keywords: Global Health; Climate change.

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Opening #Pandora’s Box at the roof of the world: #Landscape, #climate and #avian #influenza (#H5N1) (Acta Trop., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Acta Trop. 2019 Aug;196:93-101. doi: 10.1016/j.actatropica.2019.04.021. Epub 2019 May 4.

Opening Pandora’s Box at the roof of the world: Landscape, climate and avian influenza (H5N1).

Canavan BC1.

Author information: 1 Independent Scholar, Global Health and The Environment, 320 SE 62nd Ave., Portland, Oregon, United States. Electronic address: bcanavan@post.harvard.edu.

 

Abstract

The purpose of this case study is to examine how environmental disruption and agricultural practices act synergistically to create a perfect storm for the spread of avian influenza. Actors in this case study include the vast permafrost landscape of the Qinghai-Tibet Plateau; a wild goose that migrates over the Himalayas; the highest altitude railway in the world that traverses the plateau into Tibet; and an avian virus (H5N1). Commencing in 2001, tens of thousands of railway workers travelled to remote regions of the plateau to work on the railway. In order to feed and shelter these workers, the Chinese government established captive-bred goose farms as a source of high protein food. Beginning in 2005 and continuing in subsequent years, Qinghai Lake was the scene for the unprecedented appearance of avian influenza among migratory geese. This was a key moment in the global spread of H5N1 to poultry on three continents. Remote sensing technology suggested an ecological pathway for the transfer of avian viruses among chickens, captive-bred geese, and wild geese. Within a region experiencing rapid climate change, Qinghai Lake is warming even faster than the global average. This may relate to the persistent outbreaks of avian flu strains from Qinghai during the past twelve years. Globally, exponential increases in bird flu outbreaks are not merely a matter of chance mutations in flu viruses but also a result of antecedent social and environmental factors. The Qinghai case study provides real-world examples that bring these factors into sharp focus.

Copyright © 2019 Elsevier B.V. All rights reserved.

KEYWORDS: Agriculture; Avian; Climate; Influenza; Qinghai; Railway

PMID: 31063711 DOI: 10.1016/j.actatropica.2019.04.021 [Indexed for MEDLINE]

Keywords: Avian Influenza; H5N1; Panzootic; Climate change; Global warming; China.

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The #human #imperative of stabilizing #global #climatechange at 1.5°C (Science, abstract)

[Source: Science, full page: (LINK). Abstract, edited.]

The human imperative of stabilizing global climate change at 1.5°C

O. Hoegh-Guldberg1,2,*, D. Jacob3, M. Taylor4, T. Guillén Bolaños3, M. Bindi5, S. Brown6,7, I. A. Camilloni8, A. Diedhiou9, R. Djalante10,11, K. Ebi12, F. Engelbrecht13, J. Guiot14, Y. Hijioka15, S. Mehrotra16, C. W. Hope17, A. J. Payne18, H.-O. Pörtner19, S. I. Seneviratne20, A. Thomas21,22, R. Warren23, G. Zhou24

1 Global Change Institute, University of Queensland, St. Lucia, QLD 4072, Australia. 2 School of Biological Sciences, University of Queensland, St. Lucia, QLD 4072, Australia. 3 Climate Service Center Germany (GERICS), Helmholtz-Zentrum Geesthacht, Hamburg, Germany. 4 Department of Physics, University of the West Indies, Kingston, Jamaica. 5 Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence, 50144 Firenze, Italy. 6 Faculty of Engineering and Physical Sciences, University of Southampton, Boldrewood Innovation Campus, Southampton SO16 7QF, UK. 7 Department of Life and Environmental Sciences, Faculty of Science and Technology, Bournemouth University, Fern Barrow, Poole, Dorset BH12 5BB, UK. 8 Centro de Investigaciones del Mar y la Atmósfera (UBA-CONICET), UMI-IFAECI/CNRS, and Departamento de Ciencias de la Atmósfera y los Océanos (FCEN), University of Buenos Aires, Buenos Aires, Argentina. 9 Université Grenoble Alpes, French National Research Institute for Sustainable Development (IRD), CNRS, Grenoble INP, IGE, F-38000 Grenoble, France. 10 United Nations University–Institute for the Advanced Study of Sustainability (UNU-IAS), Tokyo, Japan. 11 Halu Oleo University, Kendari, South East Sulawesi, Indonesia. 12 Center for Health and the Global Environment, University of Washington, Seattle, WA, USA. 13 Global Change Institute, University of the Witwatersrand, Johannesburg 2193, South Africa. 14 Aix Marseille University, CNRS, IRD, INRA, Collège de France, CEREGE, Aix-en-Provence, France. 15 Center for Climate Change Adaptation, National Institute for Environmental Studies, Onogawa, Tsukuba, Ibaraki 305-8506, Japan. 16 World Bank, Washington, DC, USA. 17 Cambridge Judge Business School, University of Cambridge, Cambridge, UK. 18 University of Bristol, Bristol, UK. 19 Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany. 20 Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland. 21 Climate Analytics, 10961 Berlin, Germany. 22 Environmental and Life Sciences, University of the Bahamas, Nassau 76905, Bahamas. 23 Tyndall Centre for Climate Change Research and School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK. 24 State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081, China.

*Corresponding author. Email: oveh@uq.edu.au

Science  20 Sep 2019: Vol. 365, Issue 6459, eaaw6974 / DOI: 10.1126/science.aaw6974

 

The need to stabilize global climate

Climate change will be the greatest threat to humanity and global ecosystems in the coming years, and there is a pressing need to understand and communicate the impacts of warming, across the perspectives of the natural and social sciences. Hoegh-Guldberg et al. review the climate change–impact literature, expanding on the recent report of the Intergovernmental Panel on Climate Change. They provide evidence of the impacts of warming at 1°, 1.5°, and 2°C—and higher—for the physical system, ecosystems, agriculture, and human livelihoods. The benefits of limiting climate change to no more than 1.5°C above preindustrial levels would outweigh the costs.

Science, this issue p. eaaw6974

 

Structured Abstract

BACKGROUND

The United Nations Framework Convention on Climate Change (UNFCCC) was established in 1992 to pursue the “stabilization of greenhouse gas concentrations at a level that would prevent dangerous anthropogenic interferences with the climate system.” Since 1992, five major climate change assessment cycles have been completed by the UN Intergovernmental Panel on Climate Change (IPCC). These reports identified rapidly growing climate-related impacts and risks, including more intense storms, collapsing ecosystems, and record heatwaves, among many others. Once thought to be tolerable, increases in global mean surface temperature (GMST) of 2.0°C or higher than the pre-industrial period look increasingly unmanageable and hence dangerous to natural and human systems.

The Paris Climate Agreement is the most recent attempt to establish international cooperation over climate change. This agreement, ratified or acceded to by 185 countries, was designed to bring nations together voluntarily to take ambitious action on mitigating climate change, while also developing adaptation options and strategies as well as guaranteeing the means of implementation (e.g., climate finance). The Agreement is aimed at “holding the increase in the global average temperature to well below 2.0°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels, recognizing that this would significantly reduce the risks and impacts of climate change.” Many unanswered questions regarding a 1.5°C target surround the feasibility, costs, and inherent risks to natural and human systems. Consequently, countries invited the IPCC to prepare a Special Report on “the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty.” The Special Report was completed and approved by the 48th Session of the IPCC in October 2018.

ADVANCES

Multiple lines of evidence indicate that the next 0.5°C above today (which will take GMST from 1.0°C to 1.5°C above the pre-industrial period) will involve greater risks per unit temperature than those seen in the last 0.5°C increase. This principle of “accelerating risk” is also likely to drive proportionally and possibly exponentially higher risk levels in the transition from 1.5°C to 2.0°C above the pre-industrial period. We argue that this is a consequence of impacts accelerating as a function of distance from the optimal temperature for an organism or an ecosystem process. Coral reefs, for example, often appear healthy right up until the onset of mass coral bleaching and mortality, which can then destroy a reef within a few months. This also explains the observation of “tipping points” where the condition of a group of organisms or an ecosystem can appear “healthy” right up to the point of collapse, suggesting caution in extrapolating from measures of ecosystem condition to predict the future. Information of this nature needs to be combined with an appreciation of organisms’ distance from their optimal temperature.

Finally, we explore elements of the costs and benefits associated with acting in response to climate change, and come to the preliminary conclusion that restraining average global temperature to 1.5°C above the pre-industrial period would be much less costly than the damage due to inaction on global climate change.

OUTLOOK

As an IPCC expert group, we were asked to assess the impact of recent climate change (1.0°C, 2017) and the likely impact over the next 0.5° to 1.0°C of additional global warming. At the beginning of this exercise, many of us were concerned that the task would be hindered by a lack of expert literature available for 1.5°C and 2.0°C warmer worlds. Although this was the case at the time of the Paris Agreement, it has not been our experience 4 years later. With an accelerating amount of peer-reviewed scientific literature since the IPCC Special Report Global Warming of 1.5°C, it is very clear that there is an even more compelling case for deepening commitment and actions for stabilizing GMST at 1.5°C above the pre-industrial period.

 

Abstract

Increased concentrations of atmospheric greenhouse gases have led to a global mean surface temperature 1.0°C higher than during the pre-industrial period. We expand on the recent IPCC Special Report on global warming of 1.5°C and review the additional risks associated with higher levels of warming, each having major implications for multiple geographies, climates, and ecosystems. Limiting warming to 1.5°C rather than 2.0°C would be required to maintain substantial proportions of ecosystems and would have clear benefits for human health and economies. These conclusions are relevant for people everywhere, particularly in low- and middle-income countries, where the escalation of climate-related risks may prevent the achievement of the United Nations Sustainable Development Goals.

Keywords: Climate Change; Global Warming; International cooperation.

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Multidecadal #observations of the #Antarctic #icesheet from restored analog #radar #records (Proc Natl Acad Sci USA, abstract)

[Source: Proceedings of the National Academy of Sciences of the United States of America, full page: (LINK). Abstract, edited.]

Multidecadal observations of the Antarctic ice sheet from restored analog radar records

Dustin M. Schroeder, Julian A. Dowdeswell, Martin J. Siegert, Robert G. Bingham, Winnie Chu, Emma J. MacKie, Matthew R. Siegfried, Katherine I. Vega, John R. Emmons, and Keith Winstein

PNAS first published September 3, 2019 / DOI: https://doi.org/10.1073/pnas.1821646116

Edited by Eric Rignot, University of California, Irvine, CA, and approved August 8, 2019 (received for review December 19, 2018)

 

Significance

One of the greatest challenges in projecting the sea-level contributions of ice sheets over the next century is the lack of observations of conditions within and underneath the ice sheet that span more than a decade or two. By digitizing archival ice-penetrating radar data recorded in the 1970s on 35-mm optical film, we can compare modern and archival radar-sounding data at their full resolution in order to observe changes in the Antarctic ice sheet over more than 40 y. This makes it possible to investigate and model subsurface processes over both large scales and several decades for the first time.

 

Abstract

Airborne radar sounding can measure conditions within and beneath polar ice sheets. In Antarctica, most digital radar-sounding data have been collected in the last 2 decades, limiting our ability to understand processes that govern longer-term ice-sheet behavior. Here, we demonstrate how analog radar data collected over 40 y ago in Antarctica can be combined with modern records to quantify multidecadal changes. Specifically, we digitize over 400,000 line kilometers of exploratory Antarctic radar data originally recorded on 35-mm optical film between 1971 and 1979. We leverage the increased geometric and radiometric resolution of our digitization process to show how these data can be used to identify and investigate hydrologic, geologic, and topographic features beneath and within the ice sheet. To highlight their scientific potential, we compare the digitized data with contemporary radar measurements to reveal that the remnant eastern ice shelf of Thwaites Glacier in West Antarctica had thinned between 10 and 33% between 1978 and 2009. We also release the collection of scanned radargrams in their entirety in a persistent public archive along with updated geolocation data for a subset of the data that reduces the mean positioning error from 5 to 2.5 km. Together, these data represent a unique and renewed extensive, multidecadal historical baseline, critical for observing and modeling ice-sheet change on societally relevant timescales.

Antarctica – radio echo sounding – glaciology – remote sensing – archival data

Keywords: Antarctica; Climate change; Global warming.

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A 40-y record reveals gradual #Antarctic #sea #ice increases followed by decreases at rates far exceeding the rates seen in the #Arctic (Proc Natl Acad Sci USA, abstract)

[Source: Proceedings of the National Academy of Sciences of the United States of America, full page: (LINK). Abstract, edited.]

A 40-y record reveals gradual Antarctic sea ice increases followed by decreases at rates far exceeding the rates seen in the Arctic

Claire L. Parkinson

PNAS first published July 1, 2019 / DOI: https://doi.org/10.1073/pnas.1906556116

Contributed by Claire L. Parkinson, May 24, 2019 (sent for review April 16, 2019; reviewed by Will Hobbs and Douglas G. Martinson)

 

Significance

A newly completed 40-y record of satellite observations is used to quantify changes in Antarctic sea ice coverage since the late 1970s. Sea ice spreads over vast areas and has major impacts on the rest of the climate system, reflecting solar radiation and restricting ocean/atmosphere exchanges. The satellite record reveals that a gradual, decades-long overall increase in Antarctic sea ice extents reversed in 2014, with subsequent rates of decrease in 2014–2017 far exceeding the more widely publicized decay rates experienced in the Arctic. The rapid decreases reduced the Antarctic sea ice extents to their lowest values in the 40-y record, both on a yearly average basis (record low in 2017) and on a monthly basis (record low in February 2017).

 

Abstract

Following over 3 decades of gradual but uneven increases in sea ice coverage, the yearly average Antarctic sea ice extents reached a record high of 12.8 × 106 km2 in 2014, followed by a decline so precipitous that they reached their lowest value in the 40-y 1979–2018 satellite multichannel passive-microwave record, 10.7 × 106 km2, in 2017. In contrast, it took the Arctic sea ice cover a full 3 decades to register a loss that great in yearly average ice extents. Still, when considering the 40-y record as a whole, the Antarctic sea ice continues to have a positive overall trend in yearly average ice extents, although at 11,300 ± 5,300 km2⋅y−1, this trend is only 50% of the trend for 1979–2014, before the precipitous decline. Four of the 5 sectors into which the Antarctic sea ice cover is divided all also have 40-y positive trends that are well reduced from their 2014–2017 values. The one anomalous sector in this regard, the Bellingshausen/Amundsen Seas, has a 40-y negative trend, with the yearly average ice extents decreasing overall in the first 3 decades, reaching a minimum in 2007, and exhibiting an overall upward trend since 2007 (i.e., reflecting a reversal in the opposite direction from the other 4 sectors and the Antarctic sea ice cover as a whole).

sea ice – climate change – satellite Earth observations – climate trends – Antarctic sea ice

Keywords: Climate change; Global Warming; Antarctica.

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