The projected rise in extremely hot days because of global warming presents a serious risk to the health and wellbeing of the Adelaide community. Adelaide already has the highest heatwave death rate of any major Australian city. Increases in extreme heat projected by the CSIRO as a result of global warming will escalate this vulnerability to dangerous levels unless greenhouse gas emissions are reduced.
Heatwaves can lead to serious illness and death. Heatwaves have caused more deaths in Australia since 1890 than cyclones, bushfires, floods, earthquakes and severe storms combined.
At temperatures above 35 degrees, the human body’s ability to cool itself reduces, making it a common benchmark temperature for occupational health and safety experts, academic and government researchers.
There has already been a clear increase in numbers of extreme heat days over recent decades. Since the 1970s, the number of days over 35 degrees has increased by a quarter at Adelaide Airport and by 40% in the Eastern Suburbs.
The number of days over 40 degrees at Adelaide Airport have tripled since the 1970s and extreme heat days in the Eastern Suburbs have more than doubled since the 1980s.
Of most concern, in the Eastern Suburbs days over 35 degrees could increase 180% to a projected 51 days by 2090, as shown in Figure 1.
The dramatic increase in extreme temperatures in recent year (also shown in Figure 1) suggests that current levels of extreme heat may already be exceeding levels projected for 2030. If so, the climate models may be too conservative in their projections.