August 9, 2021

expert reaction to wildfires in Greece and California

Wildfires continue to rage in several places around the world, including Greece, Turkey, California and Siberia.

Prof Guillermo Rein, Professor of Fire Science, Imperial College London, said:

“While the summer is part of the expected wildfire session of many ecosystems in North America and Europe, it is the significant increase in the number of large wildfires in USA and the Mediterranean that is a concern.  There are good wildfires and bad wildfires, and we are seeing way more of the bad ones.  There are more people evacuated and more homes destroyed than the expected amount.  Firefighting costs worldwide are escalating but the number of large wildfires is not decreasing, quite the opposite.  The management of forests need to be revised and will have to change to protect people and the environment.  We are experiencing a spiral of growing destruction where forest management and climate change are bringing more damage to people and ecosystems via wildfires.”

Dr Rory Hadden, Rushbrook Lecturer in Fire Investigation, Institute of Infrastructure and Environment, University of Edinburgh, said:

“Why and how any specific wildfire starts is hard to say but we know and recognise that these are part of the natural processes of many ecosystems.  As a result, the fact that they are happening is not really surprising.  It is also, sadly, not that surprising to see fires at this scale.  The wildfire community has been warning of this for a long time now.

“We know that the size of a wildfire will be determined by the amount of fuel (vegetation) that is available to burn and the weather – particularly the wind.  The long period of hot dry weather in Greece has resulted in large areas of natural habitat becoming very dry and available to burn.  So when a fire starts, there is plenty fuel for it to consume and the fire will spread according to the terrain and the wind.  Longer periods of hotter, drier weather will lead to more wildfires.  In some places more intense rain falling the wet seasons promotes more vegetation growth which dries out and can burn in the dry season.  The precise impacts of climate change are complex but the general trends are clear.

“However, a large fire burning in isolation doesn’t present too much of a threat – they are natural processes and many ecosystems depend on them to ensure balance.  The issues arise when the fire starts to get close to buildings, structures or communities that are next to the wildland areas.  This is sometimes called the wildland urban interface – where communities are built in or near wildland areas.  It is when the fires reach these areas that they begin to have an impact.  In this sense, they are not natural disasters.  This also highlights the political aspect of the problem.

“Massive resources are required to manage or control these fires and often these efforts cannot save communities.  Instead there needs to be a recognition that the impact of wildfires can be managed through effective land management by recognising the issues at all levels of government.  Of course there are costs associated with this but prevention is better than cure and we have a growing evidence base on how to do this.  It seems that today, when we see the evidence from the IPCC that the climate is changing, and we will have longer periods of more extreme weather across the globe, it is time to rethink our approaches to wildfire management.”

Dr Thomas Smith, Associate Professor in Environmental Geography, London School of Economics (LSE), said:

What is currently happening in terms of wildfires; is it unusual?

“Wildfires are not unusual in the Mediterranean and often play an important role in maintaining shrublands and dry forest ecosystems in the region.  The scale of the fires is somewhat unusual for Turkey, with a much larger burnt area than an average year.  However, it’s important to note that fire seasons in Greece, Italy, and Turkey tend to fluctuate year-on-year, and are characterised by a big fire season every few years.  It seems that this year is a big fire season year.

What can we expect; can we predict what might happen next and are there uncertainties?

“Forecasts of fire weather from the European Forest Fire Information System (EFFIS) suggests that extreme and very extreme fire weather can be expected over the coming week or so (through to 17 August) across much of the Mediterranean, but particularly in west Turkey, parts of Siciliy and Sardinia, as well as the Greek mainland, Aegina, and Crete, with no significant change in weather predicted.  The wildfires will persist until there is some significant rainfall, and it is likely that the situation might worsen before it gets better.

Is this something we should expect more of in coming years?

“As mentioned above, wildfires are not unusual in these regions, so we can expect more fires in the Mediterranean and big fire years like 2021.  However, a warmer climate due to human-caused climate change also increases the risk of more extreme fire weather, driving larger fires that spread faster and burn with larger flames/at a higher intensity.

Do we know what causes these fires?

“Most fires in this region can be linked to human ignitions, usually accidental, but there is also the possibility of dry lightning strikes starting some of these fires.

General comment on global situation:

“Fires are not unusual in the Mediterranean and California.  Wildfire plays an important role in many of the world’s ecosystems including the northern forests of Canada and Russia as well as the savannas and shrublands across Africa, Australasia and the Americas.  However, all weather on Earth has now been modified by the impact of greenhouse gas emissions from burning fossil fuels and deforestation.  This has increased the likelihood of longer and hotter heatwaves across many places on the planet.  This, in turn, increases the probability of wildfires by lengthening the amount time vegetation is dry and available to burn.  With higher temperatures, more fuel will be dry and the relative humidity of the air will be lower.  Both of these factors contribute to faster moving and more intense wildfires, with larger flames and more energy, making them harder to fight by firefighters on the ground.  This helps to explain the record-breaking fire seasons from California to Turkey to Siberia this year.”

Dr Matthew Jones, Research Fellow, Tyndall Centre for Climate Change Research, University of East Anglia, said:

What we know from observations:

“The links between climate and wildfire are blisteringly clear in Mediterranean Europe.  In fact, this is one of the world regions where we see the most direct relationships between fire weather and major wildfire events.  Almost all large wildfires occur on days with extreme fire weather.

“Since the 1980s, the annual number of days with extreme fire weather conditions has roughly doubled, dramatically increasing the risk of wildfires.  Climate change is forcing Mediterranean landscapes into a flammable state more regularly by drying out vegetation and priming it to burn.

“It is important to acknowledge that fire weather is not the only factor affecting wildfire activity.  People are the main ignition source for fires in much of the Mediterranean and so efforts to prevent these ignitions can help to lower the risk of wildfires.  Strategically clearing vegetation from the borders of towns and villages can also help to limit the spread of wildfires into residential areas where they pose such a threat.

What we know from climate models:

“As the climate warms, extreme fire weather conditions are set to become more common.  On average, climate models suggest that we could see a ~70% increase in days with extreme fire weather at 2.0°C of global warming compared with today, and a ~150% increase at 3.0°C of global warming.  In other words, wildfire risks will accelerate as the climate warms.

“To minimise future increases in wildfire risk in the Mediterranean and beyond, it is paramount that we limit future warming to no more than 2.0°C in line with the Paris Agreement.  As a global society, the major step forward is to reduce our reliance on fossil fuels and embrace green alternatives.”

These comments are based on analysis of the following datasets:

Observations:

https://www.nature.com/articles/s41597-020-0554-z

https://cds.climate.copernicus.eu/cdsapp#!/dataset/cems-fire-historical?tab=overview

Projections:

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018GL080959

Declared interests

None received.