In higher
latitudes, forests are adapted to burn about once every century.
But with warmer temperatures comes more fires.
And why is this?
Partially because of this stuff, called duff, forest debris
that slowly builds up on the forest floor, about one inch every 17 years.
And because of the cold winters, it doesn't decompose.
Alison: It doesn't have roots.
So it's completely dependent on relative humidity for moisture.
So it actually dries very rapidly in warm,
dry conditions like we often have here in the summer.
Narration: Which means of warmer temperatures, duff becomes a potent fuel for fires.
Alison: Most Alaskans are vulnerable to wildland fire.
And with climate change, it seems that the imprint on
the landscape is growing, and so more and more communities are vulnerable.
Dr. Hoy: When a wildfire comes through, what we're really seeing is it's actually
it's not just the trees that are burning,
but it's the soil layer that's burning as well.
And so when that fire comes through and it burns that soil layer, it's
like you're taking off the lid of a cooler where everything is frozen below.
And so as that soil comes off, then we start to see the ground
start to thaw and permafrost is thawing there.
And so as we see those changes happening,
we're actually creating more climate change over time.
So wildfires are releasing carbon gases into the atmosphere.
And then as permafrost thaws, it too is releasing carbon
gases into the air, which then can create warmer conditions
which can allow for more wildfire and more thaw.
So you really see this cycle that continues up in boreal forest
and Arctic areas over time.