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

Hawaii Governor Josh Green, centre, speaks to reporters during a tour of wildfire damage in Lahaina, Hawaii. AP

A church service at King's Cathedral in Kahului on the island of Maui, Hawaii. AP

Volunteers load supplies on to a boat bound for West Maui at the Kihei boat landing. AP

A tree, uprooted by high winds, rests on the ground as a Maui County firefighter extinguishes a fire. AFP

Donated clothes pile up in Lahaina. AP

An American Red Cross worker stands at the entrance of the War Memorial Stadium, which is being used as a shelter for displaced Lahaina inhabitants in Kahului. EPA

Kamuela Kawaakoa, 34, and his six-year-old son, stand under a tarpaulin with donations for those affected by the wildfire. AFP

Hawaii stevedores and other volunteers prepare donations in Hawaii. Reuters

The Ganer family survey the ruins of their home on Malolo Place, western Maui, Hawaii, after a wildfire that killed 67 people. AFP

Damage to Lahaina on Maui island, Hawaii, on August 11, 2023, after a wildfire. AP

Damage to Kula in the Upcountry region of Maui island, Hawaii, after a wildfire. AP

Lahaina on Maui island, Hawaii, after the wildfire. AP

Burnt grasslands in the Upcountry region of Maui island extend almost as far as the eye can see. AP

A wildfire burns in Kihei, Hawaii. Thousands of residents raced to escape homes on Maui as blazes swept across the island. AP Photo

Waiola Church and the adjacent Hongwanji Mission are engulfed in Lahaina. AP

Smoke and flames have become a familiar sight across Maui. AP

Several communities were forced to evacuate as the dry season and strong winds made for dangerous fire conditions. AP

Passengers try to rest at Kahului Airport as they leave Maui. AFP

Flights off the island were delayed and cancelled leaving thousands of passengers were stranded at Kahului Airport. AFP

This handout videograb courtesy of Richard Olsten shows smoke billowing from destroyed buildings in Maui. AFP

Smoke rises above Lahaina in this handout photo courtesy of Carter Barto via Facebook. AFP

Smoke billows as wildfires driven by high winds destroy a large part of Lahaina. Reuters

Boats docked at Lahaina as smoke streams from wildfires in the Hawaii town in Maui. Reuters

Smoke obscures the old Lahaina courthouse. Reuters

A boat burns off the scorched waterfront after wildfires fanned by the winds of a distant hurricane spread. Reuters

Wildfires are destroying one of the most popular tourist areas in Hawaii. Reuters

People watch as smoke and flames fill the air from raging wildfires on Front Street in downtown Lahaina. AP

People wait on the side of the road to return to west Maui after evacuations were ordered. Reuters

Wildfires are seen across Maalaea Harbour. Reuters

At least six people have been killed in Maui, the mayor said. Reuters

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.

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.