Wildfires are raging across large parts of Europe amid severe heatwaves this week. In the UK, unprepared and unused to such events, blazes broke out following a day of record 40C heat.
London Mayor Sadiq Khan said Tuesday was the busiest day for the city’s firefighters since the Second World War.
Wildfires have grown larger and more erratic across the globe over the past decade. In 2021, the monster Dixie Fire roared through almost one million acres in northern California, leaving a burn scar the size of Rhode Island.
Over seven million acres burned in Indonesia in 2019, leading to respiratory issues for hundreds of thousands of people. That same year, bushfires erupted in Australia killing hundreds of people and destroying tens of millions of acres of land. An estimated three billion animals died or were displaced across devastated landscapes.
While wildfires have been a feature of some landscapes for millennia, they are now erupting with unprecedented size and ferociousness in new parts of the world as the climate crisis worsens.
The planet’s temperature continues to rise, mostly due to emissions caused by burning fossil fuels. This heat is bringing more frequent and intense heatwaves and droughts, says the US National Oceanic and Atmospheric Administration (NOAA), a perfect storm of conditions for wildfires to ignite.
Prolonged drought is especially dangerous for fires. Dried-out vegetation such as grasses and fallen leaves burn quickly and intensely, acting as kindling that can turn sparks or small flames into massive blazes.
Fires not only pose risk to property and infrastructure but can causeh serious health impacts. Fires release vast amounts of pollution into the air including PM2.5, miniscule particles which can lodge deep in the lungs. This is especially dangerous for people with heart and lung disease, says the US Environmental Protection Agency.
Fires also pose danger to those beyond the immediate vicinity. The ferocious 2020 wildfire season in northern California not only darkened skies in San Francisco to a Bladerunner-esque orange, but also lowered air quality as far away as New York.
Wildfires cause a cascade of environmental harm. Flames scour the landscape of vegetation and destabilize soil, which can lead to erosion even after fires have been put out. Destabilized landscapes heightened the risk of landslides, particularly during storms, which in turn can cause water contamination as sediment pours into rivers and lakes.
The world has warmed 1.1-1.2 degrees Celsius over the past 150 years, leaving much of the world hotter and drier, reports the Intergovernmental Panel on Climate Change (IPCC), the world’s leading authority on climate science.
If the world reaches 2C, heatwaves that once occurred every 10 years will happen about every other year, the IPCC reports. Droughts that happened once every 10 years will happen more than twice as often, the panel adds.
Fires will also be more intense – leading to even more wildfire risk.
The weather conditions surrounding the 2019 Australian bush fires were significantly more likely due to human-caused warming, according to World Weather Attribution, a team of international scientists who examine the role of the climate crisis in extreme events.
Some areas will be more prone to devastating blazes. Huge growth in fire activity is predicted across Sub-Saharan Africa, Brazil and Western Australia as the climate crisis grows, a 2022 United Nations report found.
Countries which have not historically experienced large wildfires are also predicted to see an increase, the UN report added, including parts of Eastern Europe and Indonesia.
The US West is proving to be a wildfire hotspot. Increasing the risk is a two-decade megadrought which would not have been possible without the climate crisis. A recent study found that the past 22 years have been the driest in the region for at least 1,200 years.
Between 1983 and 1993, an average of 2.6million acres burned across the US, according to data from the National Interagency Fire Center (NIFC). In the past decade, that number shot up to almost 7.5m acres – nearly a three-fold increase.
Much of that growth has happened in the west, especially in California, Oregon, Washington and Oklahoma. Most of the largest wildfires in recorded California history have occurred since 2000 – with the eight biggest occurring in the past five years.
