Spreading like wildfire; the double-threat of changing landscapes and climate

patches of fire burn on a grassy field in a dark landscape with trees in the background
A small fire burns in Guyana (Credit: Prof Jay Mistry, Royal Holloway, University of London)

A new research programme is speeding up efforts to understand and predict the impacts of wildfires on people, climate and wildlife, according to Dr Adriana Ford, Centre Manager at the Leverhulme Centre for Wildfires, Environment and Society.

Wildfire is the single greatest terrestrial disturbance agent on Earth. Satellite data suggest that in an average year, wildfires burn a total area of around 3.5 million km2, an area around 15 times larger than the UK. While some of these fires are purposefully controlled or are manageable, and can have benefits for ecosystems and livelihoods, other fires burn uncontrollably, with sometimes devastating consequences for safety, livelihoods, wildlife and climate.

Wildfires have been particularly prevalent this year. Currently, the east coast of Australia is suffering exceptional and catastrophic wildfire activity. In the last few weeks, raging bushfires in the states of New South Wales (NSW) and Queensland have led to six deaths, the destruction of hundreds of homes, the devastation of wildlife, and the damage will cost millions of dollars to clear up. The NSW premier Gladys Berejiklian declared a state of emergency, transferring control from the government to the Rural Fire Service Commissioner over resources, evacuation, shutdown of roads, infrastructure and essential utilities, and directing other government agencies in the hope of restoring ‘normality’.

Two people sit on the ground among piles of ash with trees in the background. Two cameras stand on tripods and other research equipment sits in boxes around the scene
Fieldwork at King’s College London (Credit: Earth Observation & Environmental Sensing Group, Department of Geography)

Only a few months prior to this, over 100 wildfires blazed within the Arctic Circle, mostly in Alaska and Siberia. These fires were unprecedented, at this usually frozen latitude, in their intensity and duration, burning for longer periods than usual. Although Arctic wildfires occur in sparsely populated areas, the changes in vegetation and landscape affect mammal species, such as caribou, which many indigenous communities rely upon. These wildfires expose people to huge amounts of smoke and harmful airborne particulates, and American space agency NASA’s Arctic-Boreal Vulnerability Experiment is now looking into the implications for their health.

NASA also confirmed that 2019 has seen the most active fire season in Brazil since 2010, with blazes ripping through huge parts of the Amazon rainforest. Meanwhile, in Indonesia, extensive toxic smoke and haze from forest fires and smouldering peat megafires has put the health of millions of people at risk, particularly poorer communities, as well increasing the threat to wildlife in the region, such as the critically endangered orangutan.

This year’s events also follow extraordinary fire activity experienced in 2017 and 2018 in Greece, Iberia, California and Canada, along with extensive burning in unusual locations including England, Sweden and Greenland, exacerbated by unseasonably hot and dry weather. Many are now concerned that such fires could become the ‘new normal’ in our changing climate. Furthermore, scientists worry this may amplify the effect on climate change, such as when carbon-rich soils in boreal regions burn to release even more carbon back into the atmosphere, and thereby increasing the effects of climate change even further.

Whilst researchers know the typical causes of wildfires – natural ignitions and human activities, both accidental and deliberate, for example to clear and manage landscapes for farming – it is not clear how and why wildfire dynamics are changing, or what are the wider consequences for people and the planet.

Aerial photo of a shrubby landscape with a dirt road passing from bottom to top on left of scene, in the centre, a patch of trees burns with smoke rising
Experimental burning of land in Kruger, South Africa (Credit: King’s College London – Earth Observation & Environmental Sensing Group, Department of Geography)

What is known is that certain conditions increase wildfire frequency, intensity, duration and spread – including high temperatures, large amounts of flammable material, low humidity, low soil moisture and strong winds – conditions which can be exacerbated by ongoing global heating and extreme weather conditions. Climate, landscape diversity and human activities – past and present – therefore combine to create enormous spatial and temporal variability in both wildfire drivers and impacts.

For example, in the coniferous forests that cover about 65 per cent of Canada, the area of burnt land has doubled in the last 75 years, probably due to global heating and the legacy of historic policies to suppress fire. The area burned by wildfire has also increased in Southeast Asia, as both a direct and indirect consequence of logging and land clearance. Conversely, the extent of burning in African savannas seems to have decreased, even as population has risen, whilst in many industrialised countries such as European countries and around the Mediterranean, shrubs and forests have sprung up on widely abandoned farms, increasingly supplying the fuel for larger and more intense fires.

Despite the claims of President Trump, severe wildfires such as those in California last year, are not simply caused by forestry mismanagement, and there is no silver bullet solution to prevent or control extreme wildfire events. To better understand the drivers of wildfires and to manage their impacts, an evidence-based approach is needed to understand the causes of wildfire. Furthermore, this must include the roles of climate change, land use, and socio-economic context – including regional or national policies influencing land use, settlement patterns, forest management practices, and much else.

We must improve recorded observations and predictions of where, when, and how fires burn, and wildfire models also need to consider the interrelationships between people and fire, how wildfires and their impacts are experienced, and how fire is used by different groups around the world. We need to develop new and more participatory research approaches to provide meaningful insights and benefits for people involved.

Understanding this interplay requires interdisciplinary collaboration, something at the core of the Leverhulme Centre for Wildfires, Environment and Society, a new ten-year research centre headed by Imperial College London and King’s College London, and working with the University of Reading and Royal Holloway, University of London. The new centre seeks to lead game-changing global research for understanding, predicting, and living with wildfires, at a time when their frequency, intensity and impact is of growing concern.

Neither science nor society yet possess the knowledge or forecasting tools needed to live in harmony with fire, but a new integrated approach will provide the best chance of obtaining a better grip of the challenge. This means interdisciplinary wildfire research involving natural and social sciences, and collaborations with wildfire practitioners and affected communities, which our centre aims to deliver.

We will lead new analytical approaches which will exploit the unparalleled richness of new global satellite data, in combination with local-scale physical, biological and social evidence. This will help to advance wildfire prediction capabilities, and to understand and quantify the impacts of wildfires on climate, the environment, and on societies and economies. This research, of course, must be in addition to continued efforts by all to combat greenhouse gas emissions and global heating, which can only worsen the frequency and severity of wildfires.

Follow the Leverhulme Centre on Twitter: @centrewildfires

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