Intense wildfires that burned through large swathes of Spain and Portugal this summer — claiming at least eight lives and forcing tens of thousands to evacuate — were massively fueled by climate change, according to a new reportpublished on Thursday. 

It states that climate change — driven primarily by the burning of oil, gas and coal — has made the weather conditions that fueled the wildfires 40 times more frequent and 30% more intense. The analysis came from the World Weather Attribution, a group of international scientists who study global warming's role in extreme weather. 

The sheer size of the fires has "been astonishing", said Clair Barnes, one of the report's authors and researcher at the Centre for Environmental Policy at Imperial College London. "Hotter, drier and more flammable conditions are becoming more severe with climate change and are giving rise to fires of unprecedented intensity."

Climate change making fires more frequent and intense 

The wildfires, which started at the end of July and raged for weeks, scorched more than 380,000 hectares in Spain and 260,000 hectares in Portugal. Together they accounted for two-thirds of burned land in Europe, which this year broke records by surpassing 1 million hectares, an area bigger than the island of Cyprus. 

While wildfires are a natural annual occurrence, intensified drought and rising temperatures are creating hot, dry, windy weather that makes them burn faster, longer and more ferociously. In Europe, as around the globe, they are becoming more frequent, intense and widespread.

The rapid analysis examined weather observations from the region, including Spain's hottest ten consecutive days on record which preceded the fires. It concluded the Spanish heatwave was 200 times more likely and 3 degrees Celsius hotter because of climate change. 

Heatwaves of a similar intensity would be expected less than every 2,500 years in a world without climate change, whereas today — at current levels of 1.3 degrees Celsius (2.3 degrees Fahrenheit) warming — they are likely to occur every 13 years, say scientists. 

Fires become more difficult to fight 

This summer Spain made its first ever request for international support to help tackle forest fires. The European Civil Protection Mechanism, an EU established system for providing member states with disaster response, was also approached by Greece, Bulgaria, Albania and Montenegro for help battling fires.

"Wildfires are reaching new extremes in Spain and Portugal," said Theodore Keeping, one of the report's authors and researcher at the Centre for Environmental Policy at Imperial College London. "Firefighters are increasingly working in chaotic and unpredictable conditions, tackling fires that behave in ways they've never seen before." 

He added that intense wildfires can create their own winds which fan longer flames and can cause flying embers that spark additional fires nearby. 

The steep terrain which characterizes northern Portugal and Spain's northwestern Galicia region, where the fires were concentrated, made fighting them even more difficult, said Ricardo Trigo, one of the report's authors and associated professor at the Geophysics, Geographical Engineering and Energy Department, University of Lisbon. 

Managing forests is key for prevention

He adds these areas are among the most wildfire-prone in Europe, because they receive significant amounts of rain during October to March — enabling lots of vegetation to grow — which then turns into fuel during dry and hot summers. 

The report emphasizes the importance of controlling vegetation in areas regularly impacted by wildfires, highlighting how the movement of populations away from the countryside to urban areas has left many forests and farms without proper management and full of dry vegetation.

With fire-fighting resources stretched to capacity, experts argue the focus needs to shift to prevention measures such as sustainable land management and improving the resilience of forests. 

Methods to do this include thinning and spacing trees properly and reducing floor vegetation through prescribed burning. Other alternatives include introducing more grazing animals like cattle and goats, which eat the dry shrubs that serve as fuel for the flames.

Shifting away from monocultures and introducing fire breaks or fuel buffer zones could also help. 

World urgently needs to shift away from fossil fuels 

So far this year, wildfires in the EU have released 38 million tons of carbon dioxide, the main greenhouse gas responsible for heating the planet. This puts the continent on track to break CO2 emission records in 2025. 

Smoke from wildfires also significantly impacts health, with particles emitted able to enter the lungs and bloodstream. Recent studies have linked wildfire smoke to 1.53 million deaths per year around the world. 

Experts in the report said the Spanish and Portuguese fires were a sign of what is to come as temperatures continue to rise, and ultimately stressed the urgency of stopping burning fossil fuels. 

"The wildfires in Europe show that 1.3 degrees Celsius of warming today is already incredibly dangerous," said Friederike Otto, one of the report's authors and professor in climate science at the Centre for Environmental Policy at Imperial College London. "Without a faster shift away from fossil fuels, we could hit 3 degrees C this century. Wildfires at this level would be catastrophic." 

Edited by: Tamsin Walker