Are the Wildfires on the West Coast of the US a Result of Climate Change?
Wednesday, November 01, 2017
The Science Magazine reports that wildfires in the Western United States have become more frequent,
burning larger areas and lasting longer than they did 30 years ago. This has
been validated this year. The Mountain West region experienced days of 100+
degrees heat waves in July of 2017. It
was also the hottest summer in California’s history with some areas in
Sacramento valley experiencing over 100 degrees.
The National Inter Agency Fire Center also
reported that this year has seen 7.8 million acres burned by wildfires as compare
to 4.2 million acres in 2016. The highlight of these wildfires was the
devastating fire in Sonoma County that destroyed hundreds of homes. So what is
the connection between climate change and the higher incidences of wildfires?
Hotter summers
Climate experts say that the Western US has experienced hotter than average temperatures every
year since 2000 except in 2010 and 2011.
This year, this has been 3.2 degrees above the historical average. The
hotter summers are drying out large areas of vegetation making them very
vulnerable to fire breakouts.
Fire and aridity have a
positive correlation as arid areas have drier vegetation that is easy to spark
up and burn faster. The Western US has
seen a rise in average summer temperatures by 1.5 degrees. A recent paper by the National Academy of Sciences
found that the area burnt by wildfires was double what it would have been
without the effects of climate change.
Over the last 30 years, the acreage burnt by wildfires has increased 5000%. Fire experts say that hotter weather dries out the
ground and vegetation moisture from winter precipitation leaves the ground and
vegetation with lots of dry matter that burns easily.
Beetles
Warmer weather has also
allowed some pests to thrive in areas other than their usual habitats. A good
example is the pine beetle which has spread to the Pacific Northwest. Infestation by this pest has left a huge
number of dead trees which dry out and become flammable tinder.
Deciduous species
Warmer temperatures are
also seeing the migration of cold tolerant species like pine and cedar to
higher elevation. These species are being replaced by deciduous species in the
lower elevations. These types of species are easy to burn as they don’t have
fire delaying foliage.
The temperature in the US
is forecasted to rise by 3.5 degrees by the year 2050. This means even hotter
and drier summers which means we could see wildfires on a greater and even more
expanded scale.
