Alaska's on Fire: Climate Change Milestone
Humankind may have reached a potential climate change
milestone. Excessive wildfires have spread across over Alaska (600 fires) and
Canada (4,000 fires) extending around 3 million acres. This year has been
exceptionally hot and dry, but has not surpassed the scorching temperatures or number
of fires in 2004.
The real problem is what lies beneath the surface,
permafrost. Permafrost is ground that remains frozen year after year and
consists of soil, rocks, and frozen water. It forms when the depth of the
winters freezing exceeds the depth of summer thaw. It covers about 85% of
Alaska and extends up to 2,000 feet below the ground. Most permafrost ranged
from 10,000 to 100,000 years old reaching back to the last ice age. Permafrost
is also one of the Earths greatest accumulations of carbon and methane. All
the permafrost in the world holds about 1.4 trillion tons of carbon and
methane, which is twice the amount in the atmosphere. If the permafrost melts
and the carbon and methane are released, it could speed up climate change.
Above the permafrost there is a layer called “duff’, which
is a layer of moss, twigs, and organic matter that is used as insulation for
the permafrost and can be up to a foot thick. When this layer is burned off
from fires “It is like ripping the insulation out of a refrigerator” according
to Sarah Zhang. A forest alone can take up to a decade to recover 4 inches of lost
duff from fires.
Forest fires are getting worse and the Alaskan fire season has
extended 40% longer than half a century ago. Last year, was Alaska's hottest
year ever recorded and is warming twice as fast as other states. The fires are
burning the insulation and melting the permafrost.
Alaskans are already becoming worried because if the
permafrost melts; vegetation, habitats
for animals, and infrastructure of buildings, roads, and sewer systems will all
start to fail and sink into the ground. The permafrost is supposed to be
permanent, but if vegetation is removed from thawing, the insulation will be
lost and the ground will become water logged, soft, and then collapse.
There is hope that ecological succession will take place and
primary producers will grow immediately after the fire and help capture more
carbon and methane than released. However, if this does not happen this
could mean more extreme weather events and could even turn into a dangerous feedback
loop.
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