Wildfires are as old as the trees. Since we've had flora, we've had fire, and that's taking it back 420 million years, where fossils of charcoalified plants point to an ancient combustion event.

But while fires across forests, grasslands and bush landscapes are a natural and necessary ecological disturbance, the devastation seen in recent years deviates considerably from the regeneration events mother earth has long managed.

Last year, more than 390 million hectares of land was burned across the globe, equating to roughly the size of the EU. In Europe, at least 30 were killed by the flames, with scores more injured and over a hundred thousand evacuated from countries including Ukraine, Turkey, and Spain.

Today, the 2026 season has already claimed the lives of more than a dozen people, as successive fires rip through 110,000 hectares across Spain and France, exacerbated by the continent's heatwaves reducing the landscape to a tinderbox.

So how has the situation gotten so bad, and how wide-ranging are the impacts of these events? CGTN spoke to professor of wildland fire science Stefan Doerr on the causes and consequences of living in a world on fire.

Europe's wildfire crossroads

The changes that we are seeing across Europe, and the world more widely, can't be reduced to a single, neat cause-and-effect, says Doerr; however, there remain some key reasons why the frequency and impact of wildfires is increasing. Unsurprisingly, a warming climate is the first of them.

"Obviously the climate has changed the occurrence and severity of fires… essentially [this is] linked to what we call the Fire Weather Index (FWI), weather that is essentially conducive to fires."

This looks like wetter, milder winters that encourage shrub growth, and hotter summers to dry out this new vegetation, creating an abundance of highly combustible fuel. Pair with unrelenting heatwaves, low humidity and precipitation, and storms with erratic winds, and summers quickly become a recipe for disaster.

In Europe, the FWI has intensified significantly, with the share of the continent experiencing high or extreme fire weather risk doubling to 40 percent since 1971. Yet it's not just longer heatwaves leading to such changes.

"In the Mediterranean, Europe, the UK, changes in land management have allowed more flammable vegetation to accumulate in the landscape. So in some places around the world, we have more 'fuel'.

"And then of course, there's an added problem that we now have more people living in what's called the rural-urban interface. So that means it's more likely that you are caught up in a fire."

The simple maths of population increase also means that you're more likely to live in an area where a fire is caused by human means. It can be accidental or intentional, but in the UK, the majority of wildfires begin this way.

"Quite often fires are actually caused by harvesters who actually hit a rock or something. But of course, it's the holidaymakers, it's a barbecue. It's also people burning building residue, cutoff shrubs and grasses. It is pretty normal, but the more people you have, the more likely something will happen."

Essentially, the combination of hotter temperatures, land management changes and urban population increase have resulted in wildfires going from a normal and necessary part of summer across Europe, to an unpredictable and often uncontrollable force with far-reaching and deadly consequences.

The hidden dangers

The short-term impacts of wildfires are devastating, and as such, highly-documented. Yet alongside the considerable damage and deaths that increasingly come with each fiery season, insidious dangers lurk with complex and far-reaching consequences.

Premature deaths from smoke inhalation is one such problem, says Doerr, where people who already have some underlying health issues are dying earlier than they would normally do, because of wildfire smoke.

"They are in the hundreds of thousands. And the more fires we see, the more of those deaths we will have. It's similar to heatwaves, in a sense: most deaths are premature… And this is certainly under-recognized.

"It's also a real problem for firefighters because they get a lot of smoke exposure, and especially in the wildfires setting, they're not necessarily wearing respiratory masks, primarily because they're so difficult to work with. So that exposure to wildfire smoke is also a real issue for them."

The type of smoke that is being inhaled is also part of the problem, explains Doerr.

"Urban fires, vehicle fires, there we have a lot of compounds in there that are highly toxic. But even woodsmoke can be very toxic. Very, very tiny particles that go deep into the lungs can enter the bloodstream, and they are quite prevalent in wildfire smoke. So in some ways, wildfire smoke can be even more damaging than other types of smoke."

The climate feedback concern

There is also a larger climate question to consider when examining the lasting effects of forest fires. When plant matter and buildings combust, they release huge amounts of carbon dioxide into the atmosphere – roughly 25 percent of the global emissions produced from fossil fuels.

While these emissions would normally be captured by new plants and vegetation growing in replacement of the dead and burned-out matter, continued deforestation and urbanisation means this recapture happens at a reduced rate.

The carbon cycle – the way carbon emissions are cyclically injected and removed from the atmosphere – has become sabotaged, and with it, global temperatures continue to climb as greenhouse gases become trapped. This phenomenon is known as the 'climate fire feedback loop', and it's "a contribution to global warming, without a doubt", says Doerr.

To complicate matters further, the wildfire side-effects of smoke and soot have their own consequences. Particulates become deposited on pack-ice, snow-caps and glaciers, encouraging melting and releasing even more trapped greenhouse gas emissions into the atmosphere. The Australian fires during the Black Summer of 2019-2020 had this very effect, where glaciers in New Zealand began melting rapidly as they became covered by soot carried over from the extensive fires.

For peat's sake

The type of land that is burned in wildfires is also a major cause for alarm. In much of northern Europe, including the UK, peat makes up an indelible part of the landscape.

It's organic matter that builds up in waterlogged, oxygen-deficient environments like bogs and mires, and takes thousands of years to form. As such, it acts as a massive carbon store, with peatlands and bogs sequestering an estimated 3.2 billion tonnes of carbon in the UK alone.

And when dry, peat still burns well – really well, in fact. The combination of superheated summers with little rain means these bogs can be ignited by something as small as a cigarette butt – and once they're on fire, it's an uphill battle to put them out, says Doerr.

"Peatland can burn deeply into the ground. You can have a whole meter of peat, which is thousands of years accumulation, burned in a single wildfire. They're also very difficult to put out because once the peat starts smoldering, you need a lot of water for this smoldering process to stop. And very often they look benign. You may not see flames at all."

With research indicating up to 90 percent of the UK's fire-driven carbon emissions are driven by peat burning, the state of Britain's peatlands is the ultimate bellwether for wider climate changes. More peat fires begets more global warming, and with it, the conditions that turn summer into a powder keg. And Doerr agrees:

"This is probably, to me, the biggest concern… because our peatlands are relatively rich in carbon compared to other countries. And we are seeing increasing occurrence of those fires."