Key indicators of Arctic climate change: 1971–2017

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Key observational indicators of climate change in the Arctic, most spanning a 47 year period (1971–2017) demonstrate fundamental changes among nine key elements of the Arctic system. We find that, coherent with increasing air temperature, there is an intensification of the hydrological cycle, evident from increases in humidity, precipitation, river discharge, glacier equilibrium line altitude and land ice wastage. Downward trends continue in sea ice thickness (and extent) and spring snow cover extent and duration, while near-surface permafrost continues to warm. Several of the climate indicators exhibit a significant statistical correlation with air temperature or precipitation, reinforcing the notion that increasing air temperatures and precipitation are drivers of major changes in various components of the Arctic system. To progress beyond a presentation of the Arctic physical climate changes, we find a correspondence between air temperature and biophysical indicators such as tundra biomass and identify numerous biophysical disruptions with cascading effects throughout the trophic levels. These include: increased delivery of organic matter and nutrients to Arctic near‐coastal zones; condensed flowering and pollination plant species periods; timing mismatch between plant flowering and pollinators; increased plant vulnerability to insect disturbance; increased shrub biomass; increased ignition of wildfires; increased growing season CO2 uptake, with counterbalancing increases in shoulder season and winter CO2 emissions; increased carbon cycling, regulated by local hydrology and permafrost thaw; conversion between terrestrial and aquatic ecosystems; and shifting animal distribution and demographics. The Arctic biophysical system is now clearly trending away from its 20th Century state and into an unprecedented state, with implications not only within but beyond the Arctic. The indicator time series of this study are freely downloadable at


  • Jason E. Box
  • William T. Colgan
  • Torben Christensen
  • Niels Martin Schmidt
  • Magnus Lund
  • Frans-Jan W. Parmentier
  • Ross Brown
  • Uma S. Bhatt
  • Eugénie S. Euskirchen
  • Vladimir E. Romanovsky
  • John E. Walsh
  • James E. Overland
  • Muyin Wang
  • Robert Corell
  • Walter N. Meier
  • Bert Wouters
  • Sebastian H. Mernild
  • Johanna Mård
  • Janet Pawlak
  • Morten Skovgaard Olsen
External organisations
  • Geological Survey of Denmark and Greenland, Copenhagen, Denmark
  • Aarhus University
  • Environment Canada
  • University of Alaska Fairbanks
  • NOAA/Pacific Marine Environmental Laboratory
  • University of Washington, Seattle
  • University of Miami
  • UiT The Arctic University of Norway, Tromsø
  • Utrecht University
  • Delft University of Technology
  • Uppsala University
  • Nansen Environmental and Remote Sensing Center
  • University Of Magallanes
  • Western Norway University of Applied Sciences
  • Norwegian Institute of Bioeconomy Research (Nibio)
  • University of Oslo
  • Global Environment and Technology Foundation
  • University of Colorado
  • Arctic Monitoring and Assessment Program (AMAP)
  • Danish Ministry of Energy, Efficiency and Climate
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Climate Research


  • Arctic climate change, observational records, AMAP
Original languageEnglish
Article number045010
JournalEnvironmental Research Letters
Issue number4
Publication statusPublished - 2019 Apr 8
Publication categoryResearch

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