Attribution of climate extreme events

Journal name:
Nature Climate Change
Volume:
5,
Pages:
725–730
Year published:
DOI:
doi:10.1038/nclimate2657
Received
Accepted
Published online

Abstract

There is a tremendous desire to attribute causes to weather and climate events that is often challenging from a physical standpoint. Headlines attributing an event solely to either human-induced climate change or natural variability can be misleading when both are invariably in play. The conventional attribution framework struggles with dynamically driven extremes because of the small signal-to-noise ratios and often uncertain nature of the forced changes. Here, we suggest that a different framing is desirable, which asks why such extremes unfold the way they do. Specifically, we suggest that it is more useful to regard the extreme circulation regime or weather event as being largely unaffected by climate change, and question whether known changes in the climate system's thermodynamic state affected the impact of the particular event. Some examples briefly illustrated include 'snowmaggedon' in February 2010, superstorm Sandy in October 2012 and supertyphoon Haiyan in November 2013, and, in more detail, the Boulder floods of September 2013, all of which were influenced by high sea surface temperatures that had a discernible human component.

At a glance

Figures

  1. Haiyan and sea level.
    Figure 1: Haiyan and sea level.

    Linear sea-level trends from August 1993 to July 2013 are shown. The global mean is 3.3 mm yr−1, and the track of supertyphoon Haiyan from 3 to 11 November 2013 is indicated in green, with the most intense phase when it was a category 5 (cat. 5) storm highlighted. Data from AVISO (http://go.nature.com/NPhaEK).

  2. August SSTs for 12-20[deg] N, 110-100[deg] W, just west of Mexico.
    Figure 2: August SSTs for 12–20° N, 110–100° W, just west of Mexico.

    The mean value is 28.92 °C for 1982–1999. The last value is for 2013.

  3. Water vapour channel imagery, GOES East 6.5 [mu]m and GOES West 6.7 [mu]m merged, for 18:45 GMT on 12 September 2013.
    Figure 3: Water vapour channel imagery, GOES East 6.5 μm and GOES West 6.7 μm merged, for 18:45 GMT on 12 September 2013.

    The image shows the extensive water vapour and associated activity both west of Mexico and in the Caribbean Sea and the river of moisture from south of Baja, Mexico to eastern Colorado. Colors are used to show more intense features. Image courtesy of WeatherTAP.com.

  4. Imagery from the 6.5-[mu]m water vapour channel of NOAA's GOES 13 satellite.
    Figure 4: Imagery from the 6.5-μm water vapour channel of NOAA's GOES 13 satellite.

    Images were taken at 05:45 GMT, on 11 (top) and 13 (bottom) September 2013. The water vapour is in the mid to upper troposphere; the brighter the imagery, the more saturated the air. Colorado is outlined in red. Images courtesy of Axel Graumann, NOAA/NESDIS/NCDC.

  5. Tropical storms Manuel and Ingrid.
    Figure 5: Tropical storms Manuel and Ingrid.

    Imagery on 15 September 2013 from Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite. NASA image courtesy of Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response Team.

References

  1. Johnstone, J. A. & Mantua, N. J. Atmospheric controls on northeast Pacific temperature variability and change, 1900–2012. Proc. Natl Acad. Sci. USA 111, 1436014365 (2014).
  2. Shepherd, T. G. Atmospheric circulation as a source of uncertainty in climate change projections. Nature Geosci. 7, 703708 (2014).
  3. IPCC Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) (Cambridge Univ. Press, 2013).
  4. Herring, S. C., Hoerling, M. P., Peterson T. C. & Stott, P. A. (eds) Explaining extreme events of 2013 from a climate perspective. Bull. Am. Meteorol. Soc. 95, S1S96 (2014).
  5. Trenberth, K. E. Attribution of climate variations and trends to human influences and natural variability. WIREs Clim. Change 2, 925930 (2011).
  6. Trenberth, K. E. Framing the way to relate climate extremes to climate change. Climatic Change 115, 283290 (2012).
  7. Wallace, J. M. Weather- and climate-related extreme events: Teachable moments. Eos 93, 120121 (2012).
  8. Stott, P. et al. in Climate Science Serving Society (eds Asrar, G. R. & Hurrell, J. W.) 307337 (Springer, 2013).
  9. Deser, C., Phillips, A., Bourdette, V. & Teng, H. Y. Uncertainty in climate change projections: The role of internal variability. Clim. Dynam. 38, 527546 (2012).
  10. Deser, C., Phillips, A. S., Alexander, M. A. & Smoliak, B. V. Projecting North American climate over the next 50 years: Uncertainty due to internal variability. J. Clim. 27, 22712296 (2014).
  11. Trenberth, K. E. Changes in precipitation with climate change. Clim. Res. 47, 123138 (2011).
  12. Trenberth, K. E. Atmospheric moisture residence times and cycling: Implications for rainfall rates with climate change. Climatic Change 39, 667694 (1998).
  13. Trenberth, K. E., Dai, A., Rasmussen, R. M. & Parsons, D. B. The changing character of precipitation. Bull. Am. Meteorol. Soc. 84, 12051217 (2003).
  14. Trenberth, K. E., Fasullo, J. T., Branstator, G. & Phillips, A. S. Seasonal aspects of the recent pause in surface warming. Nature Clim. Change 4, 911916 (2014).
  15. Branstator, G. & Teng, H. Is AMOC more predictable than North Atlantic heat content? J. Clim. 27, 35373550 (2014).
  16. Seneviratne, S. I. et al. Investigating soil moisture–climate interactions in a changing climate: A review. Earth Sci. Rev. 99, 125161 (2010).
  17. Trenberth, K. E. et al. Global warming and changes in drought. Nature Clim. Change 4, 1722 (2014).
  18. Lyons, L., Discovery or fluke: Statistics in particle physics. Phys. Today 65, 4551 (2012).
  19. Trenberth, K. E., Fasullo, J. & Smith, L. Trends and variability in column-integrated atmospheric water vapor. Clim. Dynam. 24, 741758 (2005).
  20. February 2010: Snowmageddon, Blizzard of 2010 WINTER: Unprecedented Snowfall Impacts Region (PRESTO, 2010); http://go.nature.com/IBxDJD.
  21. Blake, E. S., Kimberlain, T. B., Berg, R. J., Cangialosi, J. P. & Beven, J. L. II Tropical Cyclone Report: Hurricane Sandy Report no. AL182012 (National Hurricane Center, 2013); http://go.nature.com/sjCrrH
  22. Hurricane/Post-Tropical Cyclone Sandy, October 22–29, 2012 Service Assessment (NOAA, 2013); http://go.nature.com/BqlTxe
  23. Magnusson, L. et al. Evaluation of medium-range forecasts for hurricane Sandy. Mon. Weather Rev. 142, 19621981 (2014).
  24. Evans, A. D. & Falvey, R. J. Annual Tropical Cyclone Report 2013 (Naval Maritime Forecast Center/ Joint Typhoon Warning Center, 2013); http://go.nature.com/V9JpKu.
  25. Lin, I-I., Pun, I-F. & Lien, C-C. 'Category-6' Supertyphoon Haiyan in global warming hiatus: Contribution from subsurface ocean warming. Geophys. Res. Lett. 41, 85478553 (2014).
  26. Trenberth, K. E. & Fasullo, J. T. An apparent hiatus in global warming? Earth's Future 1, 1932 (2013).
  27. Trenberth, K. E., Fasullo, J. T. & Balmaseda, M. A. Earth's energy imbalance. J. Clim. 27, 31293144 (2014).
  28. Hoerling, M. et al. Northeast Colorado extreme rains interpreted in a climate change context. Bull. Am. Meteorol. Soc. 95 (Special issue), S15S18 (2014).
  29. Brennan, C. Boulder researcher: 2013's flood-triggering rains not caused by climate change. Daily Camera (29 September 2014); http://go.nature.com/2y9zuO.
  30. Pasch, R. J. & Zelinsky, D. A. Hurricane Manuel EP132013 (National Hurricane Center, 2014); http://go.nature.com/8ORDI9.
  31. Beven, J. L. II Hurricane Ingrid AL102013 (National Hurricane Center, 2014); http://go.nature.com/QzAQuL.
  32. Dole, R. et al. Was there a basis for anticipating the 2010 Russian heat wave? Geophys. Res. Lett. 38, L06702 (2011).
  33. Rahmstorf, S. & Coumou, D. Increase of extreme events in a warming world, Proc. Natl Acad. Sci. USA 108, 1790517909 (2011).
  34. Otto, F. E. L., Massey, N., van Oldenborgh, G. J., Jones, R. G. & Allen, M. R. Reconciling two approaches to attribution of the 2010 Russian heat wave. Geophys. Res. Lett. 39, L04702 (2012).
  35. Trenberth, K. E. & Fasullo, J. T. Climate extremes and climate change: The Russian heat wave and other climate extremes of 2010. J. Geophys. Res. 117, D17103 (2012).
  36. Seager, R. et al. Causes and Predictability of the 2011–14 California Drought (NOAA, 2014); http://go.nature.com/IBpoCA.
  37. Diffenbaugh, N. S., Swain D. L. & Touma, D. Anthropogenic warming has increased drought risk in California. Proc. Natl Acad. Sci USA 112, 39313936 (2015).

Download references

Author information

Affiliations

  1. National Center for Atmospheric Research (NCAR), PO Box 3000, Boulder, Colorado 80307, USA

    • Kevin E. Trenberth &
    • John T. Fasullo
  2. Department of Meteorology, University of Reading, Reading RG6 6BB, UK

    • Theodore G. Shepherd

Contributions

K.E.T. led the writing of the paper and conceived of the paper and figures. J.T.F analysed some data and contributed to two figures. All authors contributed to writing the manuscript.

Competing financial interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to:

Author details

Additional data