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Heat waves: Why should we be concerned?

A brief understanding of the heat waves occurring across the planet this summer.

Photo: Wix.

This summer, like many before, there has been vast news coverage on the heat waves sweeping across North and South America, Australia, Europe, East and South Asia. The intensity of the heat waves has prompted much concern for the future ahead. Year after year the summer months are becoming unbearably warm, as the climate warms. The attitudes surrounding heat waves, predominantly from the general public, have long been about sunbathing and having a beach day. For places such as the UK, that has an average July temperature of 21 degrees, a spike past that can be initially exciting. However, the reality is much more dire and critical. Across India and Pakistan many suffered as a heat wave swept across the region from March and lasted two months. While heat waves are normal in May for the introduction of Monsoon season, the severity and length of this heat wave has prompted significant attention and concern from climate scientists. The average May temperatures for Delhi are between 36 to 38 degrees. This year however, by mid-May temperatures had climbed to 49 degrees. These are not the only heat waves causing concern as heat alerts have been issued in the Netherlands, Spain, China and the US.


What is a heat wave and how are they formed?

YouTube Video: TRT World

 

Heat waves are periods of unusually high temperatures and humidity that last over a minimum of two days. Such temperatures are higher than previously recorded historical averages for the weather of a particular region. Heat waves occur as a result of high pressure air that settles and remains in place, rather than continuing its movement across the globe. Consequently, hot air sinks down and creates a sealed dome effect that traps the heat near the ground and in place. Convection currents have the ability to encourage the cooling of an overheating area, however, due to the seal created this process is inhibited. The cooler air and clouds that are pushed away from the area allow the sun a direct and unobstructed path to the ground. The ground thus absorbs the heat from the sunlight and the heat energy it produces remains trapped in the heat dome formed around the area. Heat domes contain the stagnant air that warms everyone within its vicinity. Essentially, the heat dome mimics an oven thus ‘baking’ everything in it. Cities are at significant risk due to heat waves and domes as they have less green coverage and more concrete and asphalt due to their infrastructure. Concrete, asphalt and heat produced from cars and other means also contribute to the increasing warmth.


Photo: A heat dome - Royal Meteorological Society.

The climate crisis means witnessing the increasing frequency of extreme weather events, namely heat waves. Climate change plays a critical role in their occurrence, as the warming of the climate brings hotter days. As the climate warms not only will their frequency be impacted but they are likely to become increasingly intense and last for longer periods of time. Another effect of the increasing severity of heat waves is the reduced ‘cooling periods’ overnight. Summer nights are becoming warmer and the temperature does not decline enough to provide a break in the high temperatures for recovery. The effects are vast and devastating. Near the city of Piacenza, Italy, the Po river is shrinking and the neighboring fields are increasingly browning due to drought. Monsoon season this year in India and Pakistan saw below-average rainfall. Scientists also deemed the heat wave experienced in the region was 30 times more likely due to climate change. At the time of writing this article, wildfires are currently sweeping through parts of Greece, Czech Republic and California, US. Heat waves also cause disruptions to transport infrastructure, water supply and agriculture. In India wheat crops were significantly impacted due to the heat, leading governments to ban their export. The efficiency of power plants and transmission is diminished due to the rising heat that causes blackouts and interruptions to electricity access for many, particularly the Global South. A key indicator of rising temperature has long been glaciers, heat waves have the ability to enhance the melting of ice and snow. On July 3 in the northern Italian Alps, a glacier collapsed causing an avalanche. While a heat wave is not solely responsible for this collapse, exacerbating warmer conditions and lack of replenishing snow contributes to the melting and collapsing of ice.


Staying safe during a heat wave

A surge in temperature can cause health and safety threats to all, therefore appropriate precautions should be taken in order to stay safe. Overheating is a common and immediate threat during a heat wave as well as symptoms of dizziness, nausea, fainting and heavy sweating. Excessive sweating is common under such warm conditions so drinking plenty of water will not only replace the fluids lost through sweating but ensure you remain hydrated. Hydration is key to countering symptoms such as dizziness. There is an increased risk of low blood pressure that occurs as a result of the opening of blood vessels as the body heats. Extreme low blood pressure furthers the risk of heart attack and as such it is important to be mindful of your blood pressure during a heat wave.


There are many other tips you can follow to stay safe:

  • Seek cover and shade indoors as much as possible

  • Dress in loose clothing

  • Avoid alcohol

  • Use a spray bottle to spritz your skin with cool water (personal favorite)

Photo: Wix.

Heat waves are not only dangerous for humans but also to animals and wildlife at large. Many animals are also at risk of experiencing overheating and dehydration from the heat as well as being trapped in wildfires. Young birds that are too young to fly can be injured attempting to escape nests due to overheating. Extreme heat is paired with drier conditions that diminishes food and water sources for wildlife, as well as their habitats. It is crucial that we remember that humans are not the only ones suffering during extreme weather events. While we attempt to make things a little more bearable for ourselves, here are some ways that you can help wildlife during a heat wave:

  • Set up water stations - Be sure to add stepping stones for smaller insects.

  • Provide food

  • Providing shade and shelter - Planting trees in gardens and using grass instead of artificial lawns are long-term methods of providing a cooler environment for wildlife. More immediate remedies include

Checking weather stations will help being able to plan ahead of a heat wave to ensure the necessary precautions are taken. Scientists have warned that as climate change continues the likelihood and severity of heat waves will increase making such precautions and understanding heat waves ever more important.


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