Britain's burning question

Britain’s summer of wildfires in 2018 was a taste of what’s to come. As global warming transforms Portsmouth into a seaside resort to rival any on today’s Mediterranean coast, counties like Surrey will regularly burst into flames. Dr Mark Hardiman is exploring what sort of wildfires we can expect to have to handle. His story begins thousands of years in the past.

Learn about Dr Mark Hardiman's research in our Life Solved podcast

Britain’s burning

In the summer of 2018, Britain began to burn.

The month of May was the warmest ever recorded. June was the hottest since 1995. By July, the nation was in the grips of its first heatwave since 2013, with many counties reporting drought conditions.

On Saddleworth Moor in Greater Manchester, one of the largest wildfires in living memory raged for over 3 weeks.

While the initial fire is believed to have been started by people making bonfires, this was extinguished on day 1. But the fire smouldered on, unseen, in dry peat underground – and it returned with a vengeance above ground, wild and incredibly tough to control.

As the fire approached the town of Stalybridge, around 150 people were evacuated from 50 homes – the first time such action has ever been recorded in the UK.

Airborne particle pollution from the fire spread up to 37 miles away. The fire also sparked respiratory illnesses, nosebleeds and eye problems.

Although multiple fire services and the military came together to tackle the blaze, it was only when rainfall began again that they were finally able to turn the tide.

In the end, 7 square miles of moorland were burned by the blaze.

A freak occurrence?

Perhaps not, when you consider that in little more than a week, between 24 June and 2 July, more than 100 other wildfires broke out around the nation.

These included, on the Isle of Skye, a so-called “crown fire”, in which the flames enter and spread through the treetops – a rare event in Britain.

According to Dr Mark Hardiman, Senior Lecturer in Geography at the University of Portsmouth, these wildfires are a sign of things to come.

With climate change models since the 1970s being borne out with remarkable accuracy, he says, "We have a very good idea that the world around us will change within our lifetimes.

"I’m interested to ask questions about how our environment will change, and what we can do to manage that change."

Feeling the heat

So, what can we expect the future to look like, in Britain?

Mark says:

"14 of the hottest years on record have occurred since 2001. We’re already living through climate change. Future climate models tell us that southeast England, including London and Portsmouth, will become much more Mediterranean in complexion.

"We’ll start to get hot, dry summers. What we saw as a heatwave in 2018 will be a normal summer by 2040.

"To get wildfires, you need lots of dry vegetation, littering the forest floor. As it dries out, it becomes flammable.

"Whether from lightning strikes or from people setting fires they don’t control – Britain is going to become more flammable."

The potential implications are stark.

For example, in Surrey, the most wooded county in Britain, many houses are sited next to trees and woodland. In years to come, they’ll be in the danger zone.

As Mark points out, wildfire itself is less of a threat to people than the smoke it generates. Smoke can suffocate you very quickly, even if you’re not close to its source.

"I don’t think people realise how vulnerable Britain is to fire," says Mark.

But some are waking up to the dangers. The Government has placed wildfire on the National Risk Register. And at the UK Wildfire Conference, Mark was heartened to see people from the fire service, along with lots of landscape managers, alongside academics.

There are all kinds of considerations for the future – from how and where new housing is planned, to whether new woodlands being planted will thrive in the changing climate.

There’s even the question of whether or not to do “prescribed burning” on moorland areas - setting controlled fires, to thin out the fuel source and reduce the risk of wildfire spreading.

Mark and his colleagues had a historical revelation for the conference delegates:

"When we told them fire has been in Britain for tens of thousands of years, they were amazed."

In fact, the study of historical fires cuts to the heart of Mark’s research.

Going back in time

We know Britain’s climate has been warmer in the past, and that fires accompanied the hotter weather. In Mark’s view, we can prepare better for the future if we have a better understanding of our island’s more flammable history.

He is delving tens of thousands of years back, to model what the past looked like. Because that’s a great way to figure out what we may need to plan for next.

So, how does he reconstruct the history of fire?

"When you see pictures of fire, you’ll notice a black substance everywhere. That’s charcoal – like you’d have on your barbecue. It’s a very interesting substance.

"Charcoal is formed when you get lots of heat and an absence of oxygen. It’s not very strong, but it is very stable. It can be preserved for millions of years.

"For my purposes, lakes are excellent. A lake is a big bucket that accumulates sediment over time. So I can go to a lake and take a core, which allows me to go back in time.

"You look at the layers which have formed, like a cake, and if we find charcoal, it tells us whether there was or wasn’t fire in the past."

This is a form of time travel with far-reaching implications. By considering charcoal that’s thousands of years old, Mark’s research could bear fruit in the decades ahead.

His findings about how Britain responds to wildfire may lead to future Britons living in different houses, in different kinds of communities, looking out on a different landscape.

Eternal flames?

So, what has Mark discovered about the history of fire?

His research into Britain is in its early stages. There is charcoal evidence of fires in Britain as far back as the end of the last Ice Age. Mark’s challenge is how to interpret that record:

"One of the interesting things we tend to find is that around the globe, when we get abrupt climate change – as we might expect over the next 50-100 years – we seem to get peaks in fire.

"It’s almost as if the landscape’s response to a change somehow involves fire, as if it clears out the system or responds to a drying out or a warming up. Even during cold snaps, you get increases in charcoal.

"What I’m interested in is, when you get abrupt climate change, what can fire do? And particularly, what can fire do in Britain? This hasn’t been looked at in much detail."

It’s known that people arrived in Britain at the tail end of the last Ice Age, around the time those charcoal sediments were created. Soon after there may have only been 15-20,000 people across the British Isles, but even a population this small could have had a big effect on the landscape.

"Later, during the Neolithic era, people were chopping trees down for farming and fuel. Britain naturally should be completely forested, apart from a few high spots in Scotland. It isn’t today, because our ancestors chopped so many trees down.

"It’s possible that the heathland we get across the south of England, in Hampshire and Dorset, is a totally unnatural landscape feature. It may have been created by people during these early periods.

"There’s actually been a lot of rebound. Britain is more forested now than it has been for centuries. It’s coming back."

There’s a lot for Mark to unpack here, including – crucially – how much of the charcoal found in areas across Britain may be a result of manmade fires, and how much may result from wildfire. This is a huge challenge, which he refers to with some irony as "the smoking gun."

Mark says, "People have been running over Britain for thousands of years, so untangling people ignition sources from natural ignition sources is quite tricky. But we’re working on it."

As we saw on Saddleworth Moor in the summer of 2018, even when a fire may perhaps have been started by people, the landscape and climate can take over and turn it into a wildfire. So the need to develop new solutions for the future is pressing, regardless.

Mark’s previous research gives him valuable experience in deciphering the causes of historical fires:

"I did some work on a small island in California. Islands are really interesting in terms of evolution – they’re like natural laboratories.

"We believe Columbian mammoths swam across to this particular island. Over time, they evolved to be smaller, because they didn’t need to defend themselves against the large predators found on the mainland. This is quite common – it’s called island dwarfism.

"On these islands, we have direct evidence of humans arriving, around 13,000 years ago. And the moment they did, those pygmy mammoths went extinct.

"At the same time, we seem to get a peak in charcoal. For the hunter-gatherers, fire was a really important tool. They would burn landscapes as a hunting strategy, to drive game out."

Mark’s next challenge is to explore the possible causes of fire in ancient Britain. One thing is certain:

"Humans have not just been changing the landscape since the Industrial Revolution. We’ve been doing it for a long, long time."

While this leaves the blame for climate change squarely at humankind’s feet, it also gives cause for optimism about the future. We may yet master our landscape anew as the climate changes it.

Burning questions

"I’m certain there will be environmental problems going forward," says Mark, "but I think humans can, potentially, work our way out of it.

"Humans have survived big changes – our ancestors survived the last Ice Age. Okay, we were a much smaller band of hunter-gatherers, but I’m actually quite optimistic.

"I think the solutions going forward are interdisciplinary. It’s about working with engineers, scientists, managers – we have to work together, and probably globally."

Mark’s research at the University of Portsmouth has a part to play in shaping our understanding of the challenges, so we can forge the right responses. In his teaching work, he finds plenty of reasons to expect good results:

"I look at these young minds, that are very high in talent, that come through our doors, and they’re going to be the ones that are going to figure this out. If they embrace the change, embrace the challenge, we can adapt to these things. It will be difficult, though."

For now, Mark’s own work goes on, and it won’t get any less urgent any time soon.

"It’s important to me because I don’t think we know much about it. How are we vulnerable? Should we be worried? I find my research on past fire just reveals more and more questions, which make me want to answer them even more, and even the answers reveal yet more questions!

"You could see that as quite infuriating. But I see it as fascinating."

It is a good thing for all of us that he does.

Find out more

Discover more about our research in SOLVE magazine, listen to interviews with researchers in our podcasts and read more about our sustainability and the environment research in our blog.