Sierra Nevada Forest
Carbon Facts
forest Health
is a critical
factor in
determining
whether
or not
our future
forests will
store more
carbon than
they release
Healthy Sierra Forests Are critically important
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Healthy forests absorb carbon dioxide from the atmosphere and
store it as carbon, helping to regulate our climate.
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The Sierra Nevada Region encompasses about 25 percent of
California’s total land area.
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The Sierra Nevada Region stores almost half of the state’s total
forest carbon - more than a billion metric tons. That’s equal to the
annual emissions of more than 1,000 coal-fired power plants.
Each year, when the fire season is not too extreme, healthy
Sierra forests can absorb enough additional carbon to offset
the annual carbon dioxide emissions of almost 2.7 million
passenger cars.
Threats to Sierra Nevada Forest Carbon Storage
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Overgrown forests are susceptible to drought, insect and disease
outbreaks, and large, damaging wildfires - all of which can
jeopardize carbon absorption and storage.
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The record for acres burned in a single decade on the western slope
of the Sierra will likely be set this year, with three fire seasons still
to go. While wildfires can have ecological benefits, conditions in
the Sierra right now are resulting in wildfires that far too often do
significantly more damage than good.
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A four-year drought, insect outbreak, and overly-dense forests have
led to widespread tree mortality in California. More than 29 million
trees are dead statewide. Eighty percent of those trees are in the
Sierra Nevada Region. If left standing, these trees will likely become
more fuel for large, damaging wildfires.
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Image Credit: U.S. Forest Service Climate Change Resource Center
Sierra Nevada Forest Carbon Facts
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Forests in the southern Sierra store almost
20 percent of California’s total forest carbon.
However, that area has been hit the hardest
by tree mortality. In some southern Sierra
communities, up to 85 percent of forest trees
have died.
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Today, Sierra forests store less carbon than they
did 150 years ago, even though there are more
trees. Research in the Sierra Nevada shows
that, historically, many forests were sparse
and dominated by large trees that absorbed
and stored over 25 percent more carbon than
the overgrown, small-tree dominated forests of
today.
Wildfire severity in the Sierra is increasing, from
an average of about 20 percent high severity a
decade ago to nearly 30 percent now. In highseverity fire, most trees die, start decaying, and
no longer absorb carbon.
Larger, more severe fires, like the Rim and
King Fires, can change a forested areas from
a forest to shrub or grasslands. These new
shrub and grasslands store less than 10
percent of the carbon that the forests they
replace did, and are more susceptible to
future high-severity wildfires.
Forests as a Climate Solution
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Forest restoration activities are a key long-term
climate solution. Treatments that reduce wildfire
severity and tree mortality add stability to forest
carbon.
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Prescribed burning, managed wildland fire, and
mechanical thinning treatments can augment
carbon storage in the long run by shifting stored
carbon from many small trees, to fewer, large,
old trees. These more mature forests are also
more resilient to wildfire, drought, and bark
beetles.
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Biomass represents a huge untapped
resource for the generation of heat and power.
Burning biomass in a controlled facility to
generate power, as opposed to in a wildfire,
reduces emissions and creates jobs for rural
communities.
Wildfire severity matters: Lower and
moderate severity wildfires release fewer
emissions, and result in fewer long-term
losses from current carbon stocks.
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One large, high-severity wildfire can undo much
of the annual carbon storage benefits that our
forests provide in a very short period of time.
The Rim Fire released more greenhouse gas
emissions in a few weeks than the City of San
Francisco produces in a year.
The initial pulse of emissions from a wildfire
represents only a fraction of the total emissions
that will come from the burn scar over the next
few decades as the trees killed by the fire begin
to decay.
www.RestoretheSierra.Org