Brief Communications Arising | Published:

Uncertainties in the timing of unprecedented climates

Nature volume 511, pages E3E5 (03 July 2014) | Download Citation


Arising from C. Mora et al. Nature 502, 183–187 (2013)

The question of when the signal of climate change will emerge from the background noise of climate variability—the ‘time of emergence’—is potentially important for adaptation planning. Mora et al.1 presented precise projections of the time of emergence of unprecedented regional climates. However, their methodology produces artificially early dates at which specific regions will permanently experience unprecedented climates and artificially low uncertainty in those dates everywhere. This overconfidence could impair the effectiveness of climate risk management decisions2. There is a Reply to this Brief Communication Arising by Mora, C. et al. Nature 511, (2014).

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Author information


  1. National Centre for Atmospheric Science, Department of Meteorology, University of Reading, Reading RG6 6BB, UK

    • Ed Hawkins
    •  & Rowan Sutton
  2. Department of Earth and Environment, Boston University, Massachusetts 02215, USA

    • Bruce Anderson
  3. School of Earth Sciences and Woods Institute for the Environment, Stanford University, California 94305, USA

    • Noah Diffenbaugh
  4. Federal Office of Meteorology and Climatology, MeteoSwiss, Zurich CH-8058, Switzerland

    • Irina Mahlstein
  5. Met Office Hadley Centre, FitzRoy Road, Exeter EX1 3PB. UK

    • Richard Betts
    •  & Doug McNeall
  6. Department of Geography, Exeter University, Exeter EX4 4RJ. UK

    • Richard Betts
  7. School of Geosciences, University of Edinburgh, Edinburgh EH9 3JW, UK

    • Gabi Hegerl
  8. Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK

    • Manoj Joshi
  9. Institute for Atmospheric and Climate Science, ETH Zurich, CH-8092 Zurich, Switzerland

    • Reto Knutti
  10. Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA

    • Susan Solomon
  11. Department of Science, Information Technology, Innovation and the Arts, and University of Queensland, Brisbane, Queensland 4001, Australia

    • Jozef Syktus
  12. Geophysical Fluids Dynamics Laboratory, Princeton, New Jersey 08540, USA

    • Gabriel Vecchi


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E.H. led the analysis and writing of the manuscript. B.A., N.D. and I.M. performed additional analyses, discussed the results and contributed text. All other authors contributed text.

Competing interests

Competing Financial Interests Declared none.

Corresponding author

Correspondence to Ed Hawkins.

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