This summer, we’ve seen record temperatures across the globe. June 2023 was the UK’s hottest on record, and in early July, worldwide temperature records were broken three times in one week, culminating in the hottest month ever recorded. Extreme heatwaves have raged across Europe, Asia and America, leading to wildfires, heat stress and huge evacuation efforts

In this article, we examine the cause of the heatwaves, how much of it we can attribute to climate change, and what we can do about it.

What weather systems have been behind the heatwaves?

El Niño 

This year has brought the return of a major El Niño event for the first time since 2016. El Niño is a weakening or reversal of the winds that normally blow from East to West across the Pacific Ocean. This pushes the warm waters surrounding South East Asia and Australasia eastwards, increasing surface sea temperatures.

A large school of predatory Jacks in a blue ocean above a tropical coral reef

An El Niño event can have weather and temperature impacts across the globe, intensifying rainfall in normally arid regions, and leading to drought in typically wetter areas. It can also push up global temperatures by up to 0.2 degrees C, as some of the ocean’s heat is released into the atmosphere. 

High pressure heat domes

Much of southern Europe, and parts of the USA and Asia, were caught in what is known as a ‘heat dome’ for several weeks. This is caused by high pressure conditions that effectively trap warm air close to the ground, compressing it and causing it to heat up further.  

In the UK, we have been protected from the extreme heat, as we are the other side of the jet stream. This means that we have had a small amount of the warm weather drifting across the Atlantic, but have seen a lot more of the wind, rain and cooler temperatures coming from the North.  

Were the heatwaves caused by climate change? 

While natural weather systems do cause worldwide temperatures to fluctuate, the experts agree that the extreme heatwaves seen this summer would have been near impossible if it weren’t for human-induced climate change. 

Climate change has caused these heatwaves to be hotter.  

Parts of Greece, Spain and southern Italy have experienced temperatures of above 45 degrees this summer; and China registered a new record temperature of 52.2. A study has found that the heatwaves in southern Europe were 2.5 degrees hotter due to climate change than they would have otherwise been, and in China 1 degree hotter.  

Climate change makes heatwaves last longer.  

According to data from NOAA, hotter spells last on average 24 hours longer than they did 60 years ago, and are more intense. 

Climate change makes heatwaves more frequent.  

We can expect events like this to take place in Europe once every ten years and in China once every 5. (at 1.1 degrees above pre-industrial levels.). Without climate change, such an event would have been near impossible.  

A prolonged heatwave in Sussex leads to dry, brown fields.
The earth cracks under drought conditions
Photo credit: Olive trees burn during Greek wildfire, Milos Bicanski

Photo credit: Olive trees burn during Greek wildfire, Milos Bicanski

What actions can people take to limit global warming?  

While the impact burning fossil fuels has already had on our planet will last for thousands of years, any action that we can take to prevent global heating from getting more severe is vital. 

The antidote to helplessness is action. So here are some powerful ways that you can take action today. 

  • Use your voice – Join a local action group, attend climate protests and sign petitions demanding better from our government. Write to your MP and feed into your local council’s climate action strategies. 
  • Reduce your energy carbon footprint – methods include switching to renewable energy, installing solar panels or cutting ties with fossil fuel heating by installing a heat pump. 
  • Vote with your money – choose a sustainable bank that does not support fossil fuels.  
  • Eat more local, plant-based foods – What we eat has a big impact on the planet. Choosing local produce and limiting meat in our diets can go a long way. 
  • Opt for low carbon transport – From commuting by bus, to buying an EV, or even taking the train to your next holiday destination.  
  • Plant trees – either in your own garden or as part of a carbon offsetting scheme.  
  • Take care of your mind – it is natural to feel anxious about the climate crisis. If you can, try to channel that anxiety into eco-action, eco-empathy and eco-determination. Every fraction of a degree of warming that we prevent makes a difference. 

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