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The Theory of Warmth-Induced Amplification of Extreme Weather Events

Reference
Buntgen, U., Brazdil, R., Heussner, K.-U., Hofmann, J., Kontic, R., Kyncl, T., Pfister, C., Chroma, K. and Tegel, W. 2011. Combined dendro-documentary evidence of Central European hydroclimatic springtime extremes over the last millennium. Quaternary Science Reviews 30: 3947-3959.
Authors Buntgen et al. (2011) state that anthropogenically-induced climate change is projected by climate models to increase the frequency, severity and probability of extreme meteorological phenomena; and many climate alarmists claim that we have been experiencing this effect of global warming for some time now. Buntgen et al., on the other hand, write that a palaeoclimatic perspective is "indispensable to place modern trends and events in a pre-industrial context (Battipaglia et al., 2010)" and "to disentangle effects of human greenhouse gas emission from natural forcing and internal oscillation (Hegerl et al., 2011)," stating that it "remains unclear if long-term changes in climatic mean stages, such as those associated with the Medieval Climate Anomaly (AD ~900-1300), the Little Ice Age (AD ~1300-1850), and the Recent Global Warming (AD ~1850-present), [have] affected the probability of extremes."

To help develop this essential palaeoclimatic perspective, the nine researchers analyzed 11,873 annually-resolved and absolutely-dated ring-width measurement series from living and historical fir (Abies alba Mill.) trees that had been sampled across France, Switzerland, Germany and the Czech Republic, and which continuously spanned the AD 962-2007 period, while demonstrating that ring-width extremes were triggered by anomalous variations in Central European April-June precipitation.

In discussing their findings, Buntgen et al. report there was "a fairly uniform distribution of hydroclimatic extremes throughout the Medieval Climate Anomaly, Little Ice Age and Recent Global Warming," which result brings into question, in their opinion, "the common belief that frequency and severity of such events closely relates to climate mean states." Therefore, it can be concluded, at least for the portion of Europe involved in the study of Buntgen et al., that extreme hydroclimatic phenomena were not amplified in either number or strength in response to global warming, which suggests that the same likely holds true for other portions of the planet, in contradiction of climate-alarmist claims to the contrary.

Additional References
Battipaglia, G., Frank, D.C., Buntgen, U., Dobrovolny, P., Brazdil, R., Pfister, C. and Esper, J. 2010. Five centuries of Central European temperature extremes reconstructed from tree-ring density and documentary evidence. Global and Planetary Change 72: 182-191.

Hegerl, G., Luterbacher, J., Gonzalez-Rouco, F.J., Tett, S., Crowley, T. and Xoplaki, E. 2011. Influence of human and natural forcing on European seasonal temperatures. Nature Geosciences 4: 99-103.

Archived 19 June 2012