Physiological Equivalent Temperature as Indicator for Impacts of Climate Change on Thermal Comfort of Humans

Using the measure of Physiologically Equivalent Temperature (PET) it is analysed how changes in the thermal environment can affect human well-being. Historical data used in this study have been assembled for the normal climate period 1961–1990 (CNTRL). Future conditions are calculated based on the period 2071–2100, for which simulated datasets are available, based on GCMs integrated with scenarios. The scenarios used here are the Intergovermental Panel on Climate Change (IPCC) second report on emission scenarios (SRES) A1F and B1A, which represent a worst and a moderate climate case. The results are shown for December, January and February (DJF, winter months in the northern hemisphere), and for June, July and August (JJA, summer months in the northern hemisphere). Areas with extreme and uncomfortable thermal conditions and heat stress affections can be identified. In many regions of the world, e.g. the Mediterranean and North America, changes in thermal perception by humans are shown to outpace changes in air temperature. This has major implications for the assessment of the health effects of climate change. It is highly likely that the effects of climate change on human health and well-being have been underestimated in past studies, because these were based on air temperature changes rather than changes in PET, which describes the effects of meteorological and thermo-physiological parameters.