Houses fall down.
Houses
fall
down
.
Trees fall over.
Trees
fall
over
.
Large holes form in the ground.
Large
holes
form
in
the
ground
.
Could Alaska be sinking?
Could
Alaska
be
sinking
?
That's what some villagers in Alaska have been asking themselves recently--and scientists think they know why.
That
's
what
some
villagers
in
Alaska
have
been
asking
themselves
recently
--
and
scientists
think
they
know
why
.
Warmer temperatures may be causing Alaska's frozen ground to thaw.
Warmer
temperatures
may
be
causing
Alaska
's
frozen
ground
to
thaw
.
About 85 percent of Alaska's land surface has permafrost.
About
85
percent
of
Alaska
's
land
surface
has
permafrost
.
Permafrost supports the ground above it--including trees, houses, and roads.
Permafrost
supports
the
ground
above
it
--
including
trees
,
houses
,
and
roads
.
But why is the permafrost thawing?
But
why
is
the
permafrost
thawing
?
Some scientists say that human-caused pollution is leading to global warming.
Some
scientists
say
that
human-caused
pollution
is
leading
to
global
warming
.
And most scientists agree that Alaska has been getting warmer.
And
most
scientists
agree
that
Alaska
has
been
getting
warmer
.
They say that the warmer temperature is causing permafrost to thaw in some areas.
They
say
that
the
warmer
temperature
is
causing
permafrost
to
thaw
in
some
areas
.
The thawing permafrost can cause problems for people, plants, and animals.
The
thawing
permafrost
can
cause
problems
for
people
,
plants
,
and
animals
.
"The collapsing is a problem in the villages in Alaska which are built on permafrost, and some of them may have to move to safer ground, where there is no permafrost," Weller said.
``
The
collapsing
is
a
problem
in
the
villages
in
Alaska
which
are
built
on
permafrost
,
and
some
of
them
may
have
to
move
to
safer
ground
,
where
there
is
no
permafrost
,
''
Weller
said
.
The Alaskan town of Glennallen saw its old post office collapse.
The
Alaskan
town
of
Glennallen
saw
its
old
post
office
collapse
.
And, according to James Walters, a permafrost expert at the University of Northern Iowa, house-moving companies have been very busy.
And
,
according
to
James
Walters
,
a
permafrost
expert
at
the
University
of
Northern
Iowa
,
house-moving
companies
have
been
very
busy
.
"Melting permafrost can also destroy trees and forests," Weller said.
``
Melting
permafrost
can
also
destroy
trees
and
forests
,
''
Weller
said
.
"When holes in the ground form, trees fall into them and die.
``
When
holes
in
the
ground
form
,
trees
fall
into
them
and
die
.
This could turn a forest into a swamp, and animals which need the forest will have to move elsewhere."
This
could
turn
a
forest
into
a
swamp
,
and
animals
which
need
the
forest
will
have
to
move
elsewhere
.
''
The melting could cause "severe problems."
The
melting
could
cause
``
severe
problems
.
''
Weller says: "This could take hundreds of years, but in the end Alaska will look quite different from what it looks like now."
Weller
says
:
``
This
could
take
hundreds
of
years
,
but
in
the
end
Alaska
will
look
quite
different
from
what
it
looks
like
now
.
''
Houses fall down. Trees fall over. Large holes form in the ground. Could Alaska be sinking? That's what some villagers in Alaska have been asking themselves recently--and scientists think they know why. Warmer temperatures may be causing Alaska's frozen ground to thaw.  About 85 percent of Alaska's land surface has permafrost. Permafrost supports the ground above it--including trees, houses, and roads. But why is the permafrost thawing?  Some scientists say that human-caused pollution is leading to global warming. And most scientists agree that Alaska has been getting warmer. They say that the warmer temperature is causing permafrost to thaw in some areas. The thawing permafrost can cause problems for people, plants, and animals.  "The collapsing is a problem in the villages in Alaska which are built on permafrost, and some of them may have to move to safer ground, where there is no permafrost," Weller said.  The Alaskan town of Glennallen saw its old post office collapse. And, according to James Walters, a permafrost expert at the University of Northern Iowa, house-moving companies have been very busy.  "Melting permafrost can also destroy trees and forests," Weller said. "When holes in the ground form, trees fall into them and die. This could turn a forest into a swamp, and animals which need the forest will have to move elsewhere."  The melting could cause "severe problems." Weller says: "This could take hundreds of years, but in the end Alaska will look quite different from what it looks like now."