Heat Waves

Biological adaptive capacity of human and coping mechanisms of ecosystems are affected by long term climatological changes. Technology and infrastructure are developed to prepare for projected change based on historical data. Extreme and climatic events can have severe impacts on human health and ecosystem. Robinson (2001 cited in Souch and Grimmond, 2004) defined heat wave as longer period of heat stress causing health and social effects.

Increasing trend of global warming has been associated with heat waves. According to NWF (2009), more heat waves will occur as a result of global warming. The rise of global mean temperature by 10C could result in the deaths of 350,000 additional people due to heat related health problems (Tol, 2002 cited in Souch and Grimmond, 2004). In Australia, there was temperature increase of 0.9oC since 1910 and hot days ad heat waves are more frequent than past decades (CSIRO and BOM cited in climatecommission, 2013; climatecommission, 2013).

Cities and urban areas have more heat wave events than rural areas and heat islands are more likely to be formed in cities. Heat energy absorbed from the sun during the day is trapped in urban surfaces and buildings resulting slower loss of heat and transportation and commercial sector energy usage increases heat effects in cities (DOH, 2011).

Heat wave causes a number of health impacts. Very young and old people and patients with chronic and severe illness are more likely to suffer from heat waves (DOH, 2011; NWF, 2009). Heat cramps, heat rash, heat oedema, heat syncope, heat exhaustion and heat stroke are possible heat related illnesses (DOH, 2009).

Various indices have been developed to measure heat waves based on its impacts on human health. Effective temperature and discomfort index was suggested by McGregor et. al. (2002 cited in Souch and Grimmond, 2004), summer index was developed by Watts and Kalkstein (2004 cited in Souch and Grimmond, 2004), heat wave duration index (HWDI) was described by Frich et. al. (2002 cited in Souch and Grimmond, 2004) and physiological thermal index (PET) was proposed by Matzarakis et. al. (1999 cited in Souch and Grimmond, 2004).

References

CSIRO (Commonwealth Scientific and Industrial Research Organisation) and BoM. (2007). Climate Change in Australia –Technical Report. Cited in Climatecommission (2013) Off the charts: Extreme Australian Summer Heat [Online] Available at http://climatecommission.gov.au [Accessed on 27 May 2013].

Climatecommission (2013) Off the charts: Extreme Australian Summer Heat [Online] Available at http://climatecommission.gov.au [Accessed on 27 May 2013].

Department of Health (DOH) (2009) Protecting Health and Reducing Harm from Extreme Heat and Heat waves. [Online] Available at https://www.gov.uk/ [Accessed on 27 May 2013].

Frich, P., Alexander, L.V., Della-Marta, P., Gleason, B., Haylock, M., Tank, A.M.G.K. and Peterson, T.  2002: Observed coherent changes in climatic extremes during the second half of the twentieth century. Climate Research 19, 193–212. Cited in Souch, C.  and Grimmond, C.S.B. (2004) Applied Climatology: ‘Heat Waves’. Progress in Physical Geography. 28(4) pp. 599-606.

Matzarakis, A., Mayer, H. and Iziomon, M.G. 1999: Applications of a universal thermal index: physiological equivalent temperature. International Journal of Biometeorology 43, 76–84. Cited in Souch, C.  and Grimmond, C.S.B. (2004) Applied Climatology: ‘Heat Waves’. Progress in Physical Geography. 28(4) pp. 599-606.

McGregor, G.R., Markou, M.T., Bartzokas, A. and Katsoulis, B.D. 2002: An evaluation of the nature and timing of summer human thermal discomfort in Athens, Greece. Climate Research 20, 83–94. Cited in Souch, C.  and Grimmond, C.S.B. (2004) Applied Climatology: ‘Heat Waves’. Progress in Physical Geography. 28(4) pp. 599-606.

National Wildlife Federation (NWF) (2009) More Extreme Heat Waves: Global Warming’s Wake Up Call. [Online] Available at http://www.psr.org/assets/pdfs/more-extreme-heat-waves.pdf [Accessed on 27 May 2013].

Robinson, P.J. 2001: On the definition of heat waves. Journal of Applied Meteorology 40, 762–75. Cited in Souch, C.  and Grimmond, C.S.B. (2004) Applied Climatology: ‘Heat Waves’. Progress in Physical Geography. 28(4) pp. 599-606.

Tol, R.S. 2002: Estimates of the damage cost of climate change. Part I: benchmark estimates. Environmental and Resource Economics 21, 42–73. Cited in Souch, C.  and Grimmond, C.S.B. (2004) Applied Climatology: ‘Heat Waves’. Progress in Physical Geography. 28(4) pp. 599-606.

Watts, J.D. and Kalkstein, L.S. 2004: The development of a warm-weather relative stress index for environmental applications. Journal of Applied Meteorology 43, 503–13. Cited in Souch, C.  and Grimmond, C.S.B. (2004) Applied Climatology: ‘Heat Waves’. Progress in Physical Geography. 28(4) pp. 599-606.

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