Could Climate Change
Impact Costa Rica? New
Study Says Yes
Newswise — While melting
Arctic sea ice and
glaciers have become a
symbol of climate
change, new research
from the University of
Massachusetts Amherst
indicates that highland
forests in Costa Rica
could also be seriously
affected by future
changes in climate,
reducing the number of
species in a region
famous for its
biodiversity.
“Central America is a
major, emerging “hot
spot” in the tropics
where climate change
impacts on the
environment will be
pronounced, and the loss
of species associated
with climate has already
been identified,” says
doctoral candidate
Ambarish Karmalkar of
the UMass Amherst
Climate System Research
Center.
He recently attended the
first conference
organized in Costa Rica
to study this issue.
“We have completed a
regional climate model
showing that many areas
of Costa Rica will
become warmer and drier
as climate change
accelerates, and these
changes will be
amplified at higher
elevations.”
Additional members of
the research team
include Raymond Bradley,
a professor of
geosciences at UMass
Amherst, and Henry Diaz
of the National Oceanic
and Atmospheric
Administration.
According to Karmalkar,
Costa Rica has a unique
geography that supports
a stunning array of
plants, animals and
insects. The land begins
at sea level on both the
western Pacific coast
and the eastern
Caribbean coast, rising
to over 3,000 meters
above sea level in the
central mountain range.
As the land rises,
differences in
temperature and
precipitation caused by
elevation create an
array of distinct
ecosystems stacked on
top of each other, each
one housing a unique
biological community.
Above 1,000 meters,
rising air creates a
continual cloud layer
that constantly bathes
the vegetation in
horizontal
precipitation, allowing
plants and animals to
survive the dry season
from December to April.
These cloud forests are
essential to maintaining
freshwater resources in
Costa Rica, and the
height at which the
clouds develop is a
critical factor for
these ecosystems. Since
they are highly
dependant on temperature
and precipitation, these
ecosystems are
particularly vulnerable
to climate change.
To predict the effects
of climate change, a
regional modeling system
capable of accommodating
the complex topography
of Central America was
chosen. After validating
the computer model using
rainfall and temperature
data collected in
Central America between
1961 and 1990, the team
looked at what would
happen if carbon dioxide
in the atmosphere
doubled. The results of
this medium-to-high
scenario, called the A2
scenario in reports
issued by the
Intergovernmental Panel
on Climate Change, were
striking.
“If carbon dioxide
levels double, this
region will not only
experience an increase
in temperature of more
than three Kelvins, but
all future temperatures
will likely be higher
than the complete range
of present-day
temperatures,” says
Karmalkar. “In addition,
the model simulation
indicates that high
elevation Pacific slopes
and the Caribbean
lowlands will receive up
to 30 percent less
precipitation.
Simulations also
indicate an overall
increase in the height
of the cloud base of up
to 300 meters.”
According to Karmalkar,
as temperatures rise,
various ecosystems will
try to migrate to where
they are comfortable,
moving in an upslope
direction in this case.
As they migrate, plants
and animals will disturb
other species, and
eventually run out of
space as they reach the
top of the mountains.
The result may be a loss
of many species that
can’t survive the new
conditions.
“After the extinction of
the golden toad sometime
between 1987 and 1989,
corresponding with a
warm event in the
Pacific Ocean,
scientists began
relating climate change
to the loss of
biodiversity in Costa
Rica,” says Karmalkar.
“Since then, the
Monteverde Institute has
been documenting
biological changes that
could be related to
climate change.”
Karmalkar plans to study
the entire region of
Central America,
determining large
climate dynamics of the
region and how that will
change in the future.
“Central America has a
unique annual cycle of
precipitation, with a
midsummer drought that
occurs during July and
August,” says Karmalkar.
“Knowing how climate
change will affect this
cycle will be important
for agriculture, which
is an integral part of
the economy of the
region.”
|
