‘Explosive fire growth’ in Southern California

No end in sight: California is experiencing its worst year of wildfires on record. © Getty

Are wildfires natural? As fires hit Los Angeles and tens of thousands are evacuated across Southern California, officials are blaming climate change for the state’s unusually dry conditions.

Fast-moving wildfires, driven by strong Santa Ana winds, have seen tens of thousands of people across Southern California being evacuated from their homes, and the closure of Interstate 405. And on Wednesday, fires hit one of the USA’s major cities, Los Angeles.

When winds eased slightly on Wednesday, overworked firefighters were able to catch their breath, but conditions are worsening. A combination of high winds, an incredibly dry humidity level and a fire danger of 296 is creating what officials are calling a “recipe for explosive fire growth”.

In October, fires raged across Northern California’s wine country. A wind called the Diablo (Spanish for devil) picked up fires and spread them too fast for the authorities to control. The winds reached 75mph in some places — strong enough to blow trees into power lines, leaving whole areas off the grid.

At least 42 people were confirmed dead, with 100,000 people displaced by the fires and at least 8,400 homes and other buildings destroyed. As fires subsided, residents returned to find their homes and possessions reduced to ashes.

California experiences wildfires every few years, but its fire season usually peaks in October. Officials are suggesting that with climate change, more fires, like those we are experiencing now, are occurring later in the year. And as has happened in Southern Europe, their rates are increasing.

Some, such as last year’s Clayton fires, are started deliberately. But there are any number of man-made causes, from carelessly discarded cigarette stubs to poorly attended camp fires.

But wildfires have long been part of the life cycle of forests. They return nutrients to the soil by burning dead or decaying matter. They also act as a disinfectant, removing disease-ridden plants and harmful insects from a forest ecosystem.

Ancient hunting peoples set regular fires to maintain and extend grasslands, and prevent fire-intolerant trees and shrubs from taking over.

So should we see fires as natural events or man-made disasters?

Raging debate

Some see fires as neither good nor bad, but simply natural. Authorities should focus their efforts on improving evacuation and on discouraging people from living in areas at risk. In fact, efforts to prevent wildfires have led to dangerous build-ups of plant growth which are feeding fires at lower elevations.

But, while some fires may be natural, there is little doubt that man-made climate change is causing them to increase. Warm weather and a lack of water kills trees, creating kindling for fires, while the heat also increases the length of the wildfire season. Even if fires start naturally, the conditions to stop them or to exacerbate them are man-made.

You Decide

  1. Should we see wildfires as natural events or man-made disasters?
  2. What would you take with you if a fire forced you to evacuate your town?


  1. Write a diary entry of a teenager in California who has been forced to evacuate their home.
  2. To what extent has the rate of natural disasters risen? Research earthquakes, volcanic eruptions, floods and wildfires and design a graphic illustrating the position.

Some People Say...

“Humans should be permanently evacuated from areas at risk from wildfires.”

What do you think?

Q & A

What do we know?
Fires are ravaging Southern California. Tens of thousands of people are being evacuated, and hundreds of schools have been closed due to heavy smoke. In October, wildfires raged through Northern California, killing at least 42 people, damaging or destroying 14,000 homes, and causing more than $9 billion worth of damage according to state Insurance Commissioner Dave Jones.
What do we not know?
The causes of all of the fires. Investigators are examining whether power lines falling down or electrical transformers exploding may have sparked some of them. We also do not yet know how bad the damage is in Southern California, as some areas are inaccessible.

Word Watch

Santa Ana winds
Strong, extremely dry winds that originate inland in Nevada and Utah and affect coastal Southern California.
Interstate 405
A major road running north-south through Southern California. The freeway (ie, main road) has since been reopened.
Fire danger of 296
The highest ever, according to Los Angeles Fire Chief Ralph Terrazas. The rating comes from the index to measure fire risk, the US National Fire Danger Rating System (NFDRS).
Southern Europe
There have been over 700 recorded wildfires in the EU this year. In early July, 64 people were killed in Portugal, while fires in Croatia were widespread enough to detonate land-mines that had been left unchecked after the Yugoslav war. There were more fires in the south of France and Spain.
A construction worker, Damin Pashilk, was charged on 17 counts of arson related to the Clayton Fire and other fires in the area.
Not all grassland fires are natural. Annual grassland fires in southern Vietnam stem in part from the Vietnam war: the destruction of forested areas by the US military; explosives; and mechanical land-clearing and burning operations.


PDF Download

Please click on "Print view" at the top of the page to see a print friendly version of the article.