They say their results will require climate change models to be revised

Forests in Siberia and northern Europe are more fire resistant, they say

The scientists found that forest fires in North America cooled the most

This change increases the amount of sunlight reflected back into space

Researchers at Woods Hole Research Centre looked at the impact of fires

They can burn with intense heat that destroys swathes of habitat in just a few hours and throws out huge clouds of thick black smoke.

But it seems that despite this pollution, forest fires may actually be helping to cool the planet.

Scientists have found that the destruction caused by wildfires in the huge boreal forests of north America and Eurasia can lower temperatures.

Forest fires like above can destroy huge areas of vegetation so the landscape reflects more of the sun's heat

This is because fires transform the landscape, allowing snow and ice to cover the ground and changing the amount of sunlight it reflects.

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Dark green foliage of trees tends to absorb heat from the sun while the snow covered ground is more reflective.

The study, led by Dr Brendan Rogers at Woods Hole Research Centre in Massachusetts, found that in areas where the destruction is greatest the cooling affect is also bigger.

In total it could account for twice as much cooling as other natural cooling, such as aerosols release from volcanoes, put together.

The findings could alter predictions for how the climate is likely to change as carbon dioxide emissions increase.

Dr Rogers said that climate scientists may need to factor in the affect of forest fires on global warming in their models.

He said: 'Current global fire models neglect the influence of these species-level traits and misrepresent boreal fire feedbacks to climate warming.

'We need to move beyond generic representations of trees, and use this information to make informed decisions on how to manage forest fires for climate mitigation.'

It has been commonly assumed that forest fires might contribute to global warming by releasing vast amounts of carbon dioxide into the atmosphere.

The black soot produced from these fires can also cover the surrounding landscape and absorb heat from the sun.

The graph above shows the amount of sunlight reflected by the landscape after a forest fire in North America (NA), Eurasia (EU), north east Eurasia (NEEU), southern Eurasia (SEU) and northwest Eurasia (NWEU)

Spruce forests in North America, like this one above in Yosemite National Park, are particularly flammable

Black spruce, like above in British Columbia, Canada, can absorb a lot of heat from the sun even in winter but after a forest fire the snow can lie on the ground and reflect much more of the sunlight than before

However, the researchers found that the long-term 'albedo' effect - where the colour of the landscape changes and reflects sunlight - caused by the destruction of the forest by fire has an overall cooling impact, particularly in the cold winter months.

The researchers, whose work is published in the journal Nature Geoscience, found that the forests in Alaska and Canada are dominated by black spruce trees that burn ferociously.

It is here that the forest fires also seem to cool the climate the most.

In northern Europe and Siberia, where the forests are dominated by Scots Pine and larch, their impact on the climate is 69 per cent weaker.

This, say the researchers, is because more of the vegetation that covers the ground is destroyed by the fire in the black spruce forests, opening up more of the land to snow cover.

The diagram above shows how natural and man-made influences can cause 'radiative forcing' of the climate

Forest fires release carbon dioxide into the atmosphere but they also produce cooling that lasts for years

The researchers calculated that in North America, forest fires like this can cool the climate by around 6 Watts per square metre.

In Eurasia, they found that forest fires will cool the climate by around 1.9 Watts per square metre.

Known as 'radiative forcing' this suggests that forest fires can make a significant contribution to balance global warming from carbon dioxide emissions.

Writing in the journal Nature Geoscience, Dr Rogers and his colleagues, said: 'Our results provide evidence that fire-related climate feedbacks from the two continents are decidedly different.

'It has been shown that fires in North American boreal forests may have an overall cooling effect because of the dominant surface short-wave forcing5.

'Although highly dependent on severity, this can be twice as strong as the other combined biogeochemical and aerosol forcing terms, which are generally positive and scale with carbon emissions.

'In contrast, fires in boreal Eurasia may be close to climate-neutral or have a warming effect.