| 英文摘要: | The global atmosphere is warming and human emissions are responsible. Now research shows that an increasing fraction of temperature and precipitation extremes are attributable to that warming. Last year was once again a year of extremes1. Flooding in Bangladesh, heatwaves in Australia, downpours in Kenya — all occurred during 2014, nominally the warmest on record (albeit by a small margin)1. Increasing temperatures, diminishing snow and ice, and rising sea levels contribute to unequivocal evidence for a warming world2 and research is now starting to examine whether increased greenhouse-gas concentrations and other anthropogenic factors have favoured the occurrence of some specific extreme events3. But given that unusual heat and heavy rainstorms were causing mayhem long before the rise of industrial emissions, what is the evidence that climate change has altered the expected occurrence of such extremes worldwide? Writing in Nature Climate Change, Erich Fischer and Reto Knutti examine this question4. They find that about 18% of moderate daily precipitation extremes, and about 75% of moderate daily hot extremes, that are currently occurring over land are attributable to warming. As each year goes by, evidence continues to accumulate that our climate is changing5 and that human influence plays a dominant role in observed warming2. The prevalence of extremely hot temperatures is expected to increase with warming and more moisture in the atmosphere leads to a tendency towards more extreme rainfall events, changes that have been detected in the observational record6, 7. But what has been lacking up to now is a robust calculation of how much more likely extreme temperatures and rainfall have become worldwide.
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Rickshaw drivers in Dhaka, Bangladesh carry passengers through flood waters after a heavy downpour in June 2014.
- WMO Statement on the State of the Global Climate of 2014 (WMO, 2015).
- IPCC Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) (Cambridge Univ. Press, 2013).
- Herring, S. C., Hoerling, M. P., Peterson, T. C. & Stott, P. A. (eds) Bull. Am. Meteorol. Soc. 95, S1–S96 (2014).
- Fischer, E. M. & Knutti, R. Nature Clim. Change http://dx.doi.org/10.1038/nclimate2617 (2015).
- Blunden, J. & Arndt, D. S. (eds) Bull. Am. Meteorol. Soc. 95, S1–S257 (2014).
- Zwiers, F. W., Zhang, X. & Feng, Y. J. Clim. 24, 881–892 (2011).
- Min, S-K., Zhang, X., Zwiers, F. W. & Hegerl, G. C. Nature 470, 378–381 (2011).
- Allen, M. R. Nature 421, 891–892 (2003).
- Stott, P. A., Stone, D. A. & Allen, M. R. Nature 432, 610–614 (2004).
- Pall, P. et al. Nature 470, 382–385 (2011).
- Taylor, K. E., Stouffer, R. J. & Meehl, G. A. Bull. Am. Meteorol. Soc. 93, 485–498 (2012).
- Mahlstein, I., Knutti, R., Solomon, S. & Portmann, R. W. Environ. Res. Lett. 6, 034009 (2011).
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Affiliations
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Peter Stott is at the Met Office Hadley Centre, Fitzroy Road, Exeter EX1 3PB, UK
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