Investigating the causes of wildfires

Dr Matt Jones (NERC Independent Research Fellow, School of Environmental Sciences, UEA) discusses the causes and dangers of wildfires, what we might do to combat them, and the first ever State of Wildfires report. 

 

Why are wildfires so fascinating to study? 

They're just so complicated. They’re not solely influenced by climate and weather, but also by the behaviours of people and the nature of the landscape. Wildfires need the right weather conditions, fuels, and ignition sources. Vegetation actually needs to be dry enough to burn. We need an ignition source, and that can either come from lightning or it can come from people, and the human ignitions can themselves be intentional or accidental. Another important factor is fuel load – put simply, is there enough vegetation available to burn? The interaction between the various mechanisms involved in fire is both complex and fascinating. 

There are so many factors, but one absolutely consistent factor is that a hotter, drier climate does lead to an increased risk of fire. Climate change is bad news for wildfires. 

What directed your interest towards extreme wildfire events? 

The Black Summer bushfires in Australia started around November 2019 and ran until to February 2020. They were record-breaking in terms of burned area, with 33 deaths, 65,000 evacuations, and 3,000 structures and homes lost – a huge societal and environmental impact. I was still working on the Global Carbon Budget at the time, but that event made me think, hang on, what's causing these massive wildfire events? The Black Summer turned out to be the first of a string of major global megafire seasons affecting all corners of the world. Since 2020, we’ve had record-breaking fire years in Siberia and Canada, for example. Naturally, I got drawn into studying the drivers of fires simply because these events were proving catastrophic and society needs answers as to why they happen and how they can be avoided. 

As a scientist, they're really interesting events to study, but obviously as a person living on Earth they’re pretty terrifying.  

Could you summarise why we're seeing this recent increase in wildfires and the effects of this? 

The consistent thing across the world is that climate change is increasing the frequency of droughts and heat waves, and that's leading to more flammable environments. It's why it's so important that we deliver on things like the Paris Agreement. We need to lower that future risk and the way to do that is to cut our dependence on fossil fuels. That's one angle of the answer.  

The other angle is that there are a lot of things people can do on the ground to influence how wildfires behave or how flammable the landscape is, and that's where local policies and management practices can make an impact. Key actions might involve stopping tropical deforestation through law enforcement, or planning forest plantation schemes effectively and with a view to what the climate will be like in the future. Managing fuel loads on the ground is also critical; at strategic points in the landscape, removing ground-lying vegetation and dead material can alter the behaviour of any wildfires that do descend on those areas. Also, we need to be more aware of designing or properly resourcing the protective mechanisms that we have in society, for example making sure that there's enough funding for disaster management centres, who predict where and when these fires are going to happen and put appropriate firefighting resources in place. 

 

Is the nature and impact of wildfires changing? 

We're seeing fires expand into forests and affect them more severely. We're seeing more destructive burning of more vegetation and we're also seeing higher fire intensity. We can see these patterns from space; satellite observations show more energy coming off fires, signalling that they're burning hotter and travelling faster. There's a change in how fires are behaving, even in places that have always had fires. 

The health effects of poor air quality can be felt at massive distances from the fire itself.

We often think of the effects as being immediate and direct – a fire burning through a residential area for example – but increasingly we’re seeing respiratory and other health problems related to smoke inhalation during these very extreme, widespread fire events. The health effects of poor air quality can be felt at massive distances from the fire itself. This is having an indirect, but highly impactful effect on societies. In 2023, you could see the effects of the Canadian wildfires in Seattle and New York, partly because of southerly winds. This resulted in lots of hospital admissions and, for some people with respiratory conditions, severe complications. 

In recent years we’ve seen devastating wildfires occur in Canada and Greece. Are these fires functioning in the same way? 

Well, the Canadian boreal forest is much more sensitive to climate change, not only because the forests there are not really adapted to such dry and hot conditions, but also because the rate of warming in those areas is extremely fast compared to the global average. Global climate change is often measured with one number, so while many reports focus on the effect of climate change at 1.5°C or 2.0°C, that's just an expression of the global average surface temperature change. The rate of change in the high latitudes can be more than double the global average, so the high latitudes are warming more quickly than the tropics. Warmer temperatures put more strain on plants by drying them out and also lead to more frequent heatwaves and droughts. This is one reason why we're seeing faster rates of warming and droughts in Canada and Siberia and we’re seeing wildfires happen as a result.  

Human actions have a bigger impact on where fires happen and why they happen. For example, people have a big effect on ignitions patterns and, through land use, also the passage of fire through the landscape across much of the Mediterranean. As a result, there is a lot of scope for people to influence wildfire occurrence and behaviour through land management practices, ignition avoidance legislation or education programmes, and also through active firefighting responses and strategies. Climate change is still a stressor to the situation in the Mediterranean and it still increases the risk of a fire, but the relationship between climate and fire is not as direct as in the remote forests of Canada and Siberia. 

What policies might have significant impacts on wildfires? 

If we deliver on the goals of the Paris Agreement, then we avoid a significant chunk of the additional fire risk in future. But there's also a second branch to this question which is about management. How do we manage the land to be more resilient to droughts so that when fires happen they do not behave so extremely? How do we manage the land so that homes, businesses, and infrastructure, are protected? Some strategies exist, such as actions by individuals, like clearing vegetation around homes to create a safe area. There are also larger efforts, like targeted vegetation management to reduce the likelihood of wildfires starting near towns, homes, and other buildings. 

These are warning signs that the UK may face a more fiery future, but we can learn a lot from how other countries have dealt with the problem of wildfires for a very long time.

In the UK, we're lucky that fires are rare, but in the 2022 heatwave we saw a Mediterranean climate for a couple of weeks. Lo and behold, on those days we saw record fire risk and record fire activity — for example, the fires that affected the outskirts of London. These are warning signs that the UK may face a more fiery future, but we can learn a lot from how other countries have dealt with the problem of wildfires for a very long time. 

Why did you and your team start the State of Wildfires report? 

Collectively, with colleagues at the Met Office, the European Centre for Medium-Range Weather Forecasts, and the UK Centre for Ecology and Hydrology, we became very frustrated about the lack of routine and timely analysis of extreme wildfires, and its communication to policymakers, the media and wider society.  

As a result, we dreamt up a plan to produce an annual report that catalogues the extremes of the last global fire season, explains why they happened in terms of the weather, fuel, and people factors at play, assesses how predictable the fires were, and also predicts the future risk of events on a similar scale. 

This report really combines all the cutting-edge capabilities that fire science has delivered over many decades of work from a huge community of researchers. What we are doing differently is applying those tools to recent, high-impact events and packaging these in a routine annual assessment of the past fire season. We hope to better inform a host of people — policymakers, land managers, firefighters, disaster management professionals, businesses — to help them understand recent extremes and trends in wildfires and why they are happening. Hopefully, it will inform how they develop their policies and practices to address the problem. 

How will you expand on the first report in the next iteration? 

We'd love to quantify impacts on the built environment costs, such as economic cost, and impacts on air quality from smoke. We're working with future projections of how the climate will impact wildfires.  

Why did you create the interactive wildfires map and chart alongside the report? 

We wanted to put the data in the hands of people — from media journalists to policymakers to the public. The reason being that in many parts of the world, you do not have national services that track how much fire happened in different regions each year. This is the type of thing that really allows us to assess the global situation.  

It's not too late. The choices that we make now will determine what happens next. 

Another thing is that some of the big events that tend to affect more economically developed nations are very widely reported in the news, but for other places, these extreme events pass by without recognition from the world’s media. South Africa and Botswana experienced significant periods of extreme wildfires in 2024, but it didn’t attract much news attention. The map and chart can help to bring this to people’s attention.
 

What drew you to research in the first place? 

I grew up in the industrial town of Swindon and thought I’d end up going into something corporate after university, but I became fascinated by climate science during my course. I’d always liked studying geography but in my second year of university I was really gripped by it – my interest became a passion. I had several role models in research around me who clearly saw some kind of potential, and they gave me opportunities. For example, I was fortunate enough to do an internship at Brazil’s National Institute for Space Research, where I studied the downwind impacts of fire on smoke concentrations in Brazil. It was during that time that I decided I was going to go into science.  

I studied for my PhD, which was focused on how fires impact the carbon cycle, with that work expanding into a postdoc role at Swansea University. Then I joined UEA to work on the Global Carbon Budget with Corinne Le Quéré. That was a brilliant experience as I was able to bring my knowledge of fire impacts on the carbon cycle into a really important international initiative that continuously tracks the state of the carbon cycle. 

What did you do in your early years of studying that helped you get to this point in your career? 

I think I was just very inquisitive. I really enjoyed doing project work, but I wasn't particularly good at exams. I wasn't good at cramming and retaining, so I developed a skill for the project work and being self-led. It helped me become imaginative and creative in how I addressed problems. 

These are the skills we look for in our PhD students. We look for people who have that capacity to overcome problems with a dose of determination and a dose of imaginative thinking. No scientific study ever conducted went exactly to plan, so having that resilience to problems and being able to use your knowledge or expertise around the area to independently come up with a solution is a key skill. This sets good researchers apart from others and puts them in good stead for a career in science — or, indeed, beyond science. 

Also challenge your supervisor, challenge others. It's your project and if you have a passion for a particular idea, then you should be given the space to explore it. 

What’s next for you?  

I'm growing a team here at UEA. I'm going to build a research group and expand it. We’re looking more and more at the extreme end of the fire spectrum, focusing our research on the fires that really impact people. We need to go in this direction so we can start to begin predicting wildfires and better understanding which fires we should be tackling. We’ll be looking to understand how particularly extreme fires impact forests and the carbon stocks they hold. A longer-term ambition of mine is to start an extreme fires research centre here at UEA. 

How is it that you maintain your positive outlook when studying climate change? 

I think it's because the situation is not lost. There's a lot of doom in the way climate change is portrayed in the media and that narrative of ‘it’s too late’ is really dangerous because there's always time to lessen the impacts that we face in the future. It's not too late. The choices that we make now will determine what happens next.