How does rising atmospheric CO2 affect marine organisms?

Click to locate material archived on our website by topic

Heat and Death in Vienna, Austria
Matzarakis, A., Muthers, S. and Koch, E. 2011. Human biometeorological evaluation of heat-related mortality in Vienna. Theoretical and Applied Climatology 105: 1-10.

What was done
The authors developed a relationship between heat stress and all-cause mortality in the densely populated city of Vienna (Austria), using a human biometeorological index that is known as the physiologically equivalent temperature or PET, which, in their words, "describes the thermal situation by the air temperature of a reference environment, in which the core and the skin temperature is the same as in the complex outdoor environment," which reference environment is defined as "a room with a wind velocity < 0.1 m/sec, a vapor pressure of 12 hPa and a mean radiation temperature that equals the air temperature," as described in more detail by Mayer and Hoppe (1987).

What was learned
Based upon data from the period 1970-2007, and after adjusting the long-term mortality rate to account for (1) temporal variations in the size of the population of Vienna, (2) temporal changes in life expectancy, and (3) the changing age structure of Vienna's population, the three researchers found that a significant relationship existed between heat stress and mortality. And they report that over this 38-year period, "some significant decreases of the sensitivity were found, especially in the medium heat stress levels."

What it means
With respect to the cause of this decrease in heat stress sensitivity, Matzarakis et al. state -- in the final sentence of their abstract -- that these decreases in sensitivity "could indicate active processes of long-term adaptation to the increasing heat stress," while in the discussion section of their paper, they write that such sensitivity changes "were also found for other regions," citing the studies of Davis et al. (2003), Koppe (2005), Tan et al. (2007) and Donaldson and Keatinge (2008). And in the conclusion section of their paper, they refer to these changes as "positive developments," which they truly are.

Davis, R.E., Knappenberger, P.C., Michaels, P.J. and Novicoff, W.M. 2003. Changing heat-related mortality in the United States. Environmental Health Perspectives 111: 1712-1718.

Donaldson, G.C. and Keatinge, W.R. 2008. Direct effects of rising temperatures on mortality in the UK. In: Kovats, R.S. (Ed.). Health Effects of Climate Change in the UK 2008: An Update of the Department of Health Report 2001/2002. Department of Health, United Kingdom, pp. 81-90.

Koppe, C. 2005. Gesundheitsrelevante Bewertung von thermischer Belastung unter Berucksichtigung der kurzfristigen Anpassung der Bevolkerung an die lokalen Witterungsverhaltnisse. Albert-Ludwigs-University of Freiburg, Germany.

Mayer, H. and Hoppe, P. 1987. Thermal comfort of man in different urban environments. Theoretical and Applied Climatology 38: 43-49.

Tan, J., Zheng, Y., Tang, X., Guo, C., Li, L., Song, G., Zhen, X., Yuan, D., Kalkstein, A. and Chen, H. 2007. Heat wave impacts on mortality in Shanghai 1998 and 2003. International Journal of Biometeorology 51: 193-200.

Reviewed 23 November 2011