Heatwaves: Causes, Hazards, and Mitigation

With heatwaves occurring all across Europe this Summer, here at Forest Friends Ireland we thought we would dive into the causes and hazards of heatwaves, a brainstorm of possible mitigation strategies for current and future heatwaves, and a bevy of tips to keep in mind in order to stay cool this Summer.

Here in Ireland Met Eireann has issued a Status Yellow – High Temperature Warning with temperatures predicted to fluctuate between 25-30 Degrees Celsius and possibly up to 32 Degrees next week^[1], while today Ireland has recorded its hottest temperature (33 Degrees) in 135 years at Phoenix Park, Dublin^[2].

Even though heatwaves are quite common during Summer months, due to the effects of Climate Change and Global Warming – in particular the destruction of the ozone layer, global temperatures are expected to continue to rise and heatwaves will become more common and more intense in future.

On the 11^th of August 2021 last year, an all-time temperature record for Europe was set in Sicily, Italy with a temperature of ~49 Degrees Celsius^[3].

Causes of Heatwaves

A heatwave is commonly defined as a period of unusually high temperature, usually lasting for several days or weeks.

Since common temperatures vary depending on country, each have their own criteria for classification of heatwaves.

To give an insight as to how a heatwave forms, see this explanation from www.worldatlas.com:

“A heat wave is formed when the upper atmosphere contains high pressure which makes it stationary over a region. This stationary mass of air can remain stagnant for several days and weeks, trapping more heat and reducing convection currents. As a result, there is accumulated heat and high humidity without any precipitation or rainfall. This creates the abnormally high temperatures.” ^[4]

Heatwave Hazards

Wildfires – Intense heat can create arid and dry areas which can lead to wildfires that quickly get out of hand, destroying vegetation, property, and resulting in the loss of both human and animal life.

Increased risk of heat stroke

Damage to landscapes and infrastructure – Excess heat or a present temperature that infrastructure cannot handle can cause a multitude of damages such as buckling of train tracks, melting of roads, and more. The cost of repair for infrastructure effected by heatwaves can quickly cascade into the millions/billions; For example, the International Institute for Sustainable Development (IISC) found in 2021 that one-third of Canada’s core infrastructure is not resilient to the effects of extreme weather events due to climate change and the estimated cost to improve this ranges from $150 Billion to $1 Trillion^[5].

Increased Inter-personal Conflict – In reality shows like Big Brother, the producers purposefully crank the heating systems up high in the residence that the contestants stay in as they know that an uncomfortable level of heat often leads to increased instances of argument and conflict. The increased heat can make people more irritable and lead to more violent exchanges.

Some ways we could mitigate the effects of current & future heatwaves

Planting of more mature trees and foliage in urban areas – Trees and foliage offer natural shade that can help both humans and animals to keep cool and rest, this would also have the added benefit of improving air quality and city scenery.

Green Living Roofs – Or ‘Green Roof Systems’ incorporate vegetation, soil, and a waterproofing membrane on the roofs of buildings in order to provide sustainable benefits such as: reduced storm water run-off, better acoustic performance/insulation, improved thermal performance, and improved air quality. For more on Green Roof Systems take a look at: https://iko.ie/product-systems/sustainable-solutions/green-roofs/ Also stay tuned for the unveiling of Forest Friends’ own Bus Stop Shelter Initiative, where we hope to implement the concept of Green Roof Systems into bus shelters around the country.

Installing and maintaining appropriate and effective air conditioning in public buildings

City planning with an increased emphasis on climate resilience – If we neglect to make pre-emptive changes to accommodate the effects of extreme weather in our planning and construction of infrastructure, it opens up the possibility that this infrastructure will fail in future, potentially costing millions to billions in repair and renovation, and potentially costing the loss of human life.

Tips to keep cool during heatwave season

• Never leave children or pets alone in a closed, parked vehicle!
• Ensure you and your travelling companions (and pets!) have access to plenty of drinking water and drink plenty of fluids when out and about.
• Consider diverting your route, when possible, to heavily shaded areas and areas out of direct sunlight.
• Use plenty of sunscreen and wear appropriate light clothing during the day.
• Ensure your place of residence/work is well-ventilated and a good airflow is maintained throughout.

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