Global temperature is increasing, especially over northern lands (>50° N), owing to positive feedbacks1. As this increase is most pronounced in winter, temperature seasonality (ST)—conventionally defined as the difference between summer and winter temperatures—is diminishing over time2, a phenomenon that is analogous to its equatorward decline at an annual scale. The initiation, termination and performance of vegetation photosynthetic activity are tied to threshold temperatures3. Trends in the timing of these thresholds and cumulative temperatures above them may alter vegetation productivity, or modify vegetation seasonality (SV), over time. The relationship between ST and SV is critically examined here with newly improved ground and satellite data sets. The observed diminishment of ST and SV is equivalent to 4° and 7° (5° and 6°) latitudinal shift equatorward during the past 30 years in the Arctic (boreal) region. Analysis of simulations from 17 state-of-the-art climate models4 indicates an additional STdiminishment equivalent to a 20° equatorward shift could occur this century. How SV will change in response to such large projected ST declines and the impact this will have on ecosystem services5 are not well understood. Hence the need for continued monitoring6 of northern lands as their seasonal temperature profiles evolve to resemble thosefurther south.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    & Processes and impacts of Arctic amplification: A research synthesis. Glob. Planet. Change 77, 85–96 (2011).

  2. 2.

    & Greenhouse warming and changes in the seasonal cycle of temperature: Model versus observations. Geophys. Res. Lett. 23, 1111–1114 (1996).

  3. 3.

    , , , & Increased plant growth in the northern high latitudes from 1981 to 1991. Nature 386, 698–702 (1997).

  4. 4.

    , & An overview of CMIP5 and the experiment design. Bull. Am. Meteorol. Soc. 93, 485–498 (2012).

  5. 5.

    et al. in Ecosystems and Human Well-being: Current State and Trends 717–743 (Island Press, 2005).

  6. 6.

    et al. Ecological dynamics across the arctic associated with recent climate change. Science 325, 1355–1358 (2009).

  7. 7.

    , & Variations in the Earth’s orbit: Pacemaker of the ice ages. Science 194, 1121–1132 (1976).

  8. 8.

    et al. Circumpolar arctic tundra vegetation change is linked to sea ice decline. Earth Interact. 14, 1–20 (2010).

  9. 9.

    et al. Variations in northern vegetation activity inferred from satellite data of vegetation index during 1981 to 1999. J. Geophys. Res. 106, 20069–20083 (2001).

  10. 10.

    & Satellite observations of high northern latitude vegetation productivity changes between 1982 and 2008: Ecological variability and regional differences. Environ. Res. Lett. 6, 045501 (2011).

  11. 11.

    , & Russian Arctic warming and ‘greening’ are closely tracked by tundra shrub willows. Glob. Change Biol. 16, 1542–1554 (2010).

  12. 12.

    , , & Eurasian Arctic greening reveals teleconnections and the potential for structurally novel ecosystems. Nature Clim. Change 2, 613–618 (2012).

  13. 13.

    et al. Plant community responses to experimental warming across the tundra biome. Proc. Natl Acad. Sci. USA 103, 1342–1346 (2006).

  14. 14.

    et al. Shrub expansion in tundra ecosystems: Dynamics, impacts and research priorities. Environ. Res. Lett. 6, 045509 (2011).

  15. 15.

    , & Multi-decadal changes in tundra environments and ecosystems: The International Polar Year-Back to the Future Project (IPY-BTF). Ambio 40, 555–557 (2011).

  16. 16.

    et al. A drought-induced pervasive increase in tree mortality across Canada’s boreal forests. Nature Clim. Change 1, 467–471 (2011).

  17. 17.

    , , , & Winter warming events damage sub-Arctic vegetation: Consistent evidence from an experimental manipulation and a natural event. J. Ecol. 97, 1408–1415 (2009).

  18. 18.

    et al. Climate-induced boreal forest change: Predictions versus current observations. Glob. Planet. Change 56, 274–296 (2007).

  19. 19.

    , , & Disappearing Arctic Lakes. Science 308, 1429–1429 (2005).

  20. 20.

    & Crossing the final ecological threshold in high Arctic ponds. Proc. Natl Acad. Sci. USA 104, 12395–12397 (2007).

  21. 21.

    , & Plant and vegetation dynamics on Disko Island, west Greenland: snapshots separated by over 40 years. Ambio 40, 624–637 (2011).

  22. 22.

    & Lichen recovery following heavy grazing by reindeer delayed by climate warming. Ambio 38, 11–16 (2009).

  23. 23.

    , , & Changes in snow cover characteristics over Northern Eurasia since 1966. Environ. Res. Lett. 6, 045204 (2011).

  24. 24.

    , & Energy feedbacks of northern high-latitude ecosystems to the climate system due to reduced snow cover during 20th century warming. Glob. Change Biol. 13, 2425–2438 (2007).

  25. 25.

    et al. Role of land-surface changes in Arctic summer warming. Science 310, 657–660 (2005).

  26. 26.

    et al. Winter biological processes could help convert arctic tundra to shrubland. Bioscience 55, 17–26 (2005).

  27. 27.

    & Remote sensing of industrial impact on Arctic vegetation around Noril’sk, northern Siberia: Preliminary results. Int. J. Remote Sensing 20, 2979–2990 (1999).

  28. 28.

    et al. Above ground biomass changes in the mountain birch forests and mountain heaths of Finnmarksvidda, northern Norway, in the period 1957–2006. Forest Ecol. Manage. 257, 244–257 (2009).

  29. 29.

    , & Vole and Lemming activity observed from space. Nature Clim. Change 2, 880–883 (2012).

  30. 30.

    , & Scenarios of long-term socio-economic and environmental development under climate stabilization. Technol. For. Soc. Change 74, 887–935 (2007).

Download references


This work was financially supported by the NASA Earth Science Division. We thank CRU, NSIDC, NASA MODIS Project, CAVM team and the CMIP5 climate modelling groups (listed in Supplementary Table S7) for making their data available. The authors thank U. S. Bhatt, H. E. Epstein, G. R. North, M. K. Raynolds, A. R. Stine, G. Schmidt and D. A. Walker for their comments on various parts of this article.

Author information

Author notes

    • L. Xu
    •  & R. B. Myneni

    These authors contributed equally to this work


  1. Department of Earth and Environment, Boston University, Boston, Massachusetts 02215, USA

    • L. Xu
    • , R. B. Myneni
    • , Z. Zhu
    • , J. Bi
    •  & B. T. Anderson
  2. Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska 99775, USA

    • F. S. Chapin III
    •  & E. S. Euskirchen
  3. Royal Swedish Academy of Sciences, PO Box 50005, 104 05 Stockholm, Sweden

    • T. V. Callaghan
  4. Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK

    • T. V. Callaghan
  5. Biospheric Sciences Branch, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA

    • J. E. Pinzon
    •  & C. J. Tucker
  6. Laboratoire des Sciences du Climat et de l’Environnement, CEA-CNRS-UVSQ, 91191 Gif sur Yvette, Cedex, France

    • P. Ciais
  7. Norwegian Institute for Nature Research, Fram-High North Research Center for Climate and the Environment, N-9296 Tromsø, Norway

    • H. Tømmervik
  8. Arctic Centre, University of Lapland, FI-96101 Rovaniemi, Finland

    • B. C. Forbes
  9. Department of Ecology, Peking University, Beijing 100871, China

    • S. L. Piao
  10. Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China

    • S. L. Piao
  11. Bay Area Environmental Research Institute, NASA Ames Research Center, Moffett Field, California 94035, USA

    • S. Ganguly
  12. NASA Advanced Supercomputing Division, Ames Research Center, Moffett Field, California 94035, USA

    • R. R. Nemani
  13. The Woods Hole Research Center, Woods Hole, Falmouth, Massachusetts 02540, USA

    • S. J. Goetz
    •  & P. S. A. Beck
  14. Department of Environmental Sciences, Huxley College, Western Washington University, Bellingham, Washington 98225, USA

    • A. G. Bunn
  15. State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing 100101, China

    • C. Cao
  16. School of Resource and Environment, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, China

    • C. Cao
  17. National Snow and Ice Data Center, University of Colorado, Boulder, Colorado 80309, USA

    • J. C. Stroeve


  1. Search for L. Xu in:

  2. Search for R. B. Myneni in:

  3. Search for F. S. Chapin III in:

  4. Search for T. V. Callaghan in:

  5. Search for J. E. Pinzon in:

  6. Search for C. J. Tucker in:

  7. Search for Z. Zhu in:

  8. Search for J. Bi in:

  9. Search for P. Ciais in:

  10. Search for H. Tømmervik in:

  11. Search for E. S. Euskirchen in:

  12. Search for B. C. Forbes in:

  13. Search for S. L. Piao in:

  14. Search for B. T. Anderson in:

  15. Search for S. Ganguly in:

  16. Search for R. R. Nemani in:

  17. Search for S. J. Goetz in:

  18. Search for P. S. A. Beck in:

  19. Search for A. G. Bunn in:

  20. Search for C. Cao in:

  21. Search for J. C. Stroeve in:


The analysis was performed by X.L., R.B.M, Z.Z and J.B. All authors contributed with ideas, writing and discussions.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to L. Xu or R. B. Myneni.

Supplementary information

PDF files

  1. 1.

    Supplementary Information

    Supplementary Information

About this article

Publication history





Further reading