Experts blame humans for ‘major shift’ in cause of wildfires as it’s revealed blazes started by people rather than lightning or natural causes are becoming the ‘new norm’
- Scientists from CU Boulder analyzed fire data in the US between 1984 and 2016
- They found the overwhelming majority of wildfires are now caused by humans
- The team combined satellite imagery with 1.8 million government documents
- Fires caused by humans are hard to predict because they’re not tied to seasons
An new study of wildfires in America between 1984 and 2016 has found that human-caused blazes have become more common than any other type.
The team, led by the CU Boulder Earth Lab, expects the shift will make future fires harder to predict by decoupling them from weather patterns.
It could also lead to serious environmental destruction as regions not accustomed to regular seasonal fires try to cope with the damages, often without appropriate resources.
New research from CU Boulder has found humans are now the number one source of wildfires in the US, surpassing lightning strikes and other natural sources
In the past, the strongest fires were caused by natural ignition types, like lightning strikes or El Niño winds, which also tended to be seasonal and easier to predict.
Human caused, or anthropogenic, fires tend to be less hot and cover less territory. Yet, they’re also more frequent and harder to predict because they’re not directly tied to seasons, something they say has become ‘the new normal.’
‘The shift to more human-caused fires results in decreased fire intensity and size, but that may not necessarily be a good thing,’ lead researcher Megan Cattau told Eurekalert.
‘There’s been a focus on extreme fires, but any deviation from historical fire patterns, from what that land evolved with, can cause problems.’
The team looked at fire data across the US between 1984 and 2016, breaking down the country into 3,300 grid pieces taken from satellite imagery, each of which measured 31 miles by 31 miles.
Fires caused by humans are harder to predict because they’re not directly linked to seasonal weather patterns, making them harder to prepare for
While human caused fires tend to be smaller and less hot than fires caused by lightning, they’re also more frequent and can occur in unexpected regions that may not have the appropriate resources to fight fire, making the damages worse than they should be
They collated the grid info with data from more than 1.8 million individual government records along, alongside information collected by the US Forest Service’s Fire Program Analysis Fire-Occurrence Database.
To try and explain the shift, the team points to climate change and construction.
Rising annual temperatures have left many areas drier and covered with more combustible fuel sources, including grass, brush, and dead trees.
One explanation offered by researchers is the continuing residential and commercial development across the US, which is exposing more and more territory to potentially dangerous human activity, like fireworks, smoking, camping and more
‘We can’t even call it a fire season anymore–it’s nearly all year round,’ lead researcher Megan Cattau says
At the same time, humans have continued to build in new areas for residential and commercial developments, exposing new areas to potentially dangerous human activity, like fireworks or smoking.
‘As our world sees increased development, we can also expect to see increased human ignitions,’ said Cattau. ‘This can impact people’s safety, especially those from vulnerable populations.’
‘And this shift is also bringing fires into places where there wasn’t fire before, which can damage ecosystems.’
Looking to the future, researchers say that regular fires caused by humans are likely to become even more frequent.
‘We can’t even call it a fire season anymore–it’s nearly all year round,’ Cattau said.
