About forest fires
Why fires start, how they spread and what fire means for nature.
Forest fire is both a danger and a natural part of the forest. Here we explain what starts fires, how they behave and how they have shaped Norwegian nature.
What are the most common causes of forest fires?
Around nine in ten forest fires in Norway are caused by people. Common causes are campfires, barbecues and disposable grills, smoking, sparks from trains and forestry work.
Lightning is the most important natural cause.
What types of forest fire are there?
A low surface fire burns in the vegetation on the ground and typically spreads 9–10 metres a minute. A high surface fire also takes young trees and spreads 10–30 metres a minute. A crown fire burns in the treetops, spreads 30–40 metres a minute and is the hardest to stop.
A ground fire burns down in the soil and spreads slowly, but can be hard to put out completely. Spotting is when sparks and burning pieces are blown ahead of the fire and start new fires.
Is forest fire only harmful to nature?
No. Fire is a natural part of the northern coniferous forest. Dry pine forest has naturally burned about every 50 years, while bilberry spruce forest burns about every 150 to 200 years.
Before the 1600s, probably about a hundred times more forest burned in Norway than today, and in the 1800s about 13,000 decares (1,300 ha) a year burned on average.
Is smoke from forest fires dangerous?
Smoke from an outdoor fire usually only irritates the eyes and airways, causing coughing and stinging. Call 113 for serious symptoms such as breathing difficulties or loss of consciousness, or if you have been in the smoke for a long time. Pregnant women with symptoms should always see a doctor.
Over time, wildfire smoke is a growing health problem. According to the Norwegian Institute of Public Health, deaths linked to wildfire smoke in Europe more than doubled from 1990 to 2019. Children, older people and people with heart or lung disease are especially vulnerable.
Will there be more forest fires as the climate changes?
In Norway, more days with high and very high forest fire danger are expected towards 2100, especially in the south-east. How much more often fires will actually occur is still uncertain.
Worldwide, the number of very intense forest fires has doubled since 2003, partly because higher temperatures bring longer dry spells.
The fires also affect the climate. In an opinion piece in October 2026 (in Norwegian), Nils Anders Røkke of SINTEF points out that forest fires in France released around 3.3 million tonnes of CO₂ in July, according to Copernicus, and cites research in the journal Science finding that global emissions from forest fires rose by 60 per cent from 2001 to 2023.