Are this summer's wildfires a sign of things to come as climate change intensifies?

Devastating inferno in Hawaii comes amid record-breaking fire season in Canada and after huge disruption from blazes in Mediterranean

The out-of-control blazes that killed more than 50 people on the Hawaiian island of Maui are the latest in a string of wildfires to have caused havoc in recent months.

Rhodes and Crete, Greek islands popular with holidaymakers, were badly hit, while the Italian island of Sicily has suffered devastating fires too.

Canada is among the worst-affected countries this summer, with its wildfires in 2023 being more than twice as large as the country has had before.

So are this year’s fires further evidence of the effects of climate change or part of normal variability from year to year?

Which countries have been heavily hit by wildfires this year?

The carbon emissions from Canada’s wildfires this year, at 290 million tonnes by the end of last month, according to figures from the EU’s Copernicus Atmospheric Monitoring Service, are double the previous record of 138 million tonnes set in 2014.

In a statement this month, Copernicus said parts of Canada had been hit by "unprecedented wildfire activity", with nearly all provinces and territories affected.

"Warm and dry weather has created conditions conducive to the record-breaking scale of the 2023 wildfires in Canada. Climate change is making such conditions more likely and increase the chance of a longer fire season," Copernicus said.

There have also been heavy fires in eastern Russia.

Other years have seen outbreaks that claimed more lives, such as Portugal in May and October 2017, coastal areas of Attica in Greece in 2018 and California in the same year, each of which killed more than 100 people.

This year’s wildfires in the Mediterranean, while not leading to large death tolls on the same scale, have nonetheless caused huge economic disruption in key holiday regions, such as Rhodes and Crete.

"If you look at the Mediterranean as a whole, [there have been] other seasons where more area has been burnt but in the number of people evacuated, economic impact, this year is really bad," said Stefan Doerr, professor of wildland fire science at Swansea University in the UK.

What global trends in wildfires are evident?

Wildfires are not always destructive, as some landscapes have long undergone periodic burning, which can encourage new growth and help certain seeds to germinate.

About 70 per cent of the area burnt by wildfires globally is in Africa, where blazes affecting savannah and grassland tend not to have the destructive consequences they do elsewhere.

"They rarely kill people or cause major economic and environmental damage," Prof Doerr said.

Stefan Doerr, professor of wildland fire science at Swansea University in the UK. Photo: Prof Stefan Doerr

There has been a recent decline in the area of land burnt in Africa each year, in part because of the conversion of savannah and grassland to less flammable agricultural land. Farming areas tend not to have periodic burning.

Also, parts of north-west Africa are experiencing fewer savannah fires because the region receives more rainfall as a result of climate change.

Better suppression of fires has also helped to limit the spread in some regions.

As a result of these trends, the total area burnt globally each year has fallen in recent decades, but Prof Doerr cautioned that this trend based on a global average did not give a clear picture of what is happening.

"This totally distracts from the fact we’re having very, very severe fires in many regions of the world right now," Prof Doerr said.

A more meaningful approach than looking at the global wildfire total is to consider what is happening in individual countries, where concerning trends have emerged.

What effect is climate change having on wildfires?

A report released this year by the Organisation for Economic Co-operation and Development (OECD), Taming Wildfires in the Context of Climate Change, said in many parts of the world wildfires were occurring more often and becoming more severe, with the fire season lasting longer.

There are also, the report said, more "extreme wildfires", which are typically large and intense, last a long time and have severe consequences.

"In Australia, the average wildfire frequency has doubled since 1980," the report stated. "In the forests of the western United States, wildfire severity … increased eight-fold between 1985 and 2017."

A key worry is that there is more of what researchers call "fire weather", conditions that are conducive to flames developing and spreading.

These involve long dry periods, hot days, low relative humidity and strong winds, the last of which can fan flames and cause them to spread rapidly, with winds a key factor in the fires affecting Hawaii.

Since 1979, Prof Doerr said, there has been a 27 per cent increase in the number of fire weather days around the world "due to global warming".

"And with the further warming, this trend in rising fire weather will accelerate this trend further," he added. "The really extreme weather is getting worse – flames are higher, flames move faster, the fire is more difficult to control."

In the long term, there will be some areas where wildfires will be less common as a result of desertification, Prof Doerr said.

However, he added that many forest regions of the world would suffer more and increasingly extreme fires in the coming decades, with significant consequences.

Updated: August 12, 2023, 3:00 AM