Heatwaves

Many parts of the Northern Hemisphere have experienced heatwaves over the last month. Gallargues-le-Mountueux recorded France’s highest ever temperature of 45.9°C, beating the existing record by 1.8°C. Cambridge recorded the highest temperature ever in the UK. In June, the summit Mount Blanc recorded a temperature of 7°C, whereas normally it would have been below 0°C. Records were broken across Switzerland, Germany, Austria and Spain.

The impacts of heatwaves are often underestimated. Images of hurricanes and floods may have a greater impact, but the effects of heatwaves can be more devastating. For example, in 2018, there was an increase of c. 300 deaths more than normal due to the heatwave, but it was described by officials as a minor rise. Had 300 people been killed by floods or storm surges it would have been described as a disaster. The deaths in heatwaves are often associated with pre-existing conditions, such as heart disease or lung problems. Also there is little or no damage to property, so the impacts are harder to detect.

It is likely that heatwaves will become more frequent and more intense. This is largely down to two factors – increasing levels of atmospheric greenhouse gases, and an increased concentration of people in urban areas. Climate change is believed to have made the 2003 heatwave twice as likely as it would have been without any human impact (on climate). The extreme heatwave in southern Europe in 2017 is believed to have been made ten times more likely by climate change. The 2003 heatwave was said to be a 1:1000 year event – by 2015 the UK’s Met Office stated that such as event had become a 1:100 year event, and that by 2040 such events would be commonplace. The June heatwave that affected Europe was said to have been made at least five, and possibly 100, times more likely due to human-induced climate change. It was also 4°C hotter than heatwaves a century ago

It is possible to manage heatwaves. The can be predicted, and people can be advised to stay indoors, keep well-hydrated, and use community buildings in extreme cases to provide shelter and water. Buildings can be made more heatwave proof e.g. use of white walls, green roofs to reduce the temperature inside the building. However, some people and places are more vulnerable to the impact of heatwaves. People living in densely populated slums, with roofs built from corrugated iron may experience extremely high day time temperatures. For those living in poor countries, public health systems may be stretched and underfunded, and may be less able to provide assistance to those living in remote rural areas.