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Why is it so hot? A look at heatwaves – and how nature can help us cope

It’s felt like a year of heatwaves already – and we’re only in July. Zoe Quiroz Cullen, Head of Climate and International Policy, explores why these heatwaves are happening and how nature can help us to adapt to a changing climate.

Another week, another heatwave. 

While the inspirational England team feeds our football fever, temperatures are, yet again, reaching fever pitch in the UK. 

Once occasional and standout events, these periods of extreme heat are becoming more frequent, more intense, and impacting our lives in very real ways. From transport infrastructure under pressure, to stifling temperatures on shadeless streets and playgrounds, and in buildings not designed for temperatures upwards of 30 degrees, to greatly increased wildfire risk. The list goes on.
 

Why are we experiencing more heatwaves? 

Heatwaves develop in the UK when South or South Easterly winds bringing hot air from Southern Europe or North Africa meet persistent high pressure over the UK. The hot air sinks, warming the land (and sea), causing temperatures to steadily climb. 

A Met Office map showing the daily maximum temperature for each area in the UK to hit the threshold for a heatwave. London and its surrounding areas are shown in dark red - 28 degrees. Around that area, spreading through to East Anglia and the South East is slightly lighter red - 27 degrees. The semi circle west of that shows 26 degree threshold. The rest of the UK, including Cornwall, Devon, Wales, north of England, Scotland and Northern Ireland has a threshold value of 25

Met Office heatwave threshold map © Crown Copyright 

When the temperature threshold is crossed for three or more consecutive days, we have a heatwave.   

What is changing, increasingly rapidly, is the frequency, intensity and duration of these events - driven by human-induced climate change. Now in early July, we are already in our third heatwave. We saw peak temperature records smashed in May and June, and the UK's first red heat alert two weeks ago - prompted by a 40oC day forecast. Meanwhile, Europe is enduring even higher temperatures and its worst heatwave in history.   

Human-induced climate change, caused by the build-up of carbon dioxide and other greenhouse gases in the atmosphere, has already made one in 10-year extreme temperature events heat events 2.8x more likely - and one in 50-year events 4.8x more likely. 

Whilst the current heatwave is not expected to reach such dramatic temperature peaks, it is set to be notable for its length. Up to 10 days of 30+ degrees is no joke if you are teaching (or trying to learn!) in a sweltering classroom, working outside for prolonged periods, or suffer from health conditions that make heat stress even harder to deal with.   

Wildlife suffers too, as birds struggle to find food for their young, wetland breeding sites become drier, and many animals struggle with access to water, for example. 

What can we do about it? 

A key thing is to recognise that we have not arrived at a 'new normal' that is stable. Unchecked, climate change means a continually shifting baseline, with significantly greater heat stress in the future, and other extreme events, including drought, storms and flooding. Acting now is key to cope with the impacts of climate change we are already experiencing, and to curb future extremes.   

For a nation of nature lovers, we are fortunate that one of the most powerful solutions we have available - alongside rapidly reducing emissions from fossil fuels and increasing energy efficiency - is the recovery of the natural world. 

And it is a win-win-win solution that helps reduce climate change, increases the resilience of communities and the economy to extreme weather, and brings immense health and wellbeing benefits.

The UK is one of the most nature depleted countries in the world, and the most depleted in the G7. Yet healthy ecosystems provide nature-based solutions to climate change. 

From woodlands and urban 'mini forests', to restored peatlands and seagrass meadows, and sustainable farming systems, such as regenerative agriculture - these habitats lock up carbon in plants, soils and sediments, capture precious water and minimise flooding, act as natural air conditioning systems, and are more resistant to fire.

Responsive Coloured Box

Heat & Nature in London

Two weeks ago, the Mayor of London launched Heat Ready London, the capital's first heat plan - in the midst of June's record-breaking heat wave. London Wildlife Trust fed into this report, which calls for a suite of actions, including expanding and maintaining tree canopy, green spaces and water features for greener and cooler neighbourhoods - particularly in most at risk areas. The economic and social need is clear. Recent research warned of the significant impact of climate change on the health and finances of Londoners, and an annual cost of £10-15 billion per year by 2050, unless major steps are taken now to tackle climate change and build resilience.

The key message is, the more we weave nature back into all our land and seascapes - our streets and gardens, our farmland, our industrial centres and community spaces, our rivers, nature reserves and national parks - the healthier, safer, and better off we will be. 

Nature is critical green infrastructure, and The Wildlife Trusts are on the frontline of these efforts - working with communities, land managers and businesses to bring back nature across the UK. 
 

Everyone has a role to play

From putting out water sources and creating shade to helping wildlife survive the current heatwave, to preparing for the future. 

Why not try: 

  • wildlife gardening
  • collaborating in your community to care for shared green spaces
  • managing your farm for food and nature
  • volunteering with your local Wildlife Trust; or
  • holding your local MP to account in calling for nature to be woven into the heart of all new developments
     

If you ever find yourself wondering, how much nature really matters… think of walking in 30 degree heat, and the gift of shade under a large tree. And extrapolate.

Fixing nature fixes so much more.

A large group of people shelter under the canopy of a large tree from the blazing sun in a heatwave. The shade provided by the canopy of the tree is almost entirely filled by people, with no one sat out in the sun

People sheltering from heatwave under the canopy of a tree © Zoe Quiroz Cullen

If you are part of a community group working to contribute to nature recovery and respond to the climate emergency; and/or improve nature-rich spaces and access to them - The Green Community Grants Programme is open, offering flexible one-year grants of up to £25,000 for not-for-profit organisations in England, Scotland and Wales, with thanks to Postcode Lottery UK.

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