- Oceans cover over 70 percent
of the Earth's surface.
They not only serve as the
planet's largest habitat,
but also help to regulate
the global climate.
- The ocean is a continuous
body of salt water that
surrounds the continents.
It is divided into four major regions:
the Pacific, Atlantic, Indian and Arctic.
The ocean contains traces of
all chemical elements found
on Earth.
But it tastes salty because
sodium and chloride ions in
rainwater runoff, and minerals
from geothermal vents on the
sea floor.
Climate change is altering
the ocean in three major ways.
First, the ocean is getting
warmer. The greenhouse effect
not only warms the planet, but
also raises the temperature
of the world's oceans.
Over the past century, the
ocean's surface temperature
rose at an average rate at
about .13 degrees fahrenheit
per decade. And during
the past 30 years, sea
surface temperature has been
consistently higher than at any
other time on record.
This warmer water vaporizes
quickly, fueling stronger and
more frequent storms.
Higher temperatures also
threaten delicate ocean life like
coral reefs. And disrupt the food chain.
From krill, to penguins, to seals.
Second, since 1993, the seas
have been rising at a rate
that's twice as fast
as the long-term trend.
Sea levels rise not only because
water expands when it heats
up, but also due to melting
glaciers and ice sheets.
Rising seas contribute to
flooding on once dry lands in
coastal regions.
A third consequence of climate change is
ocean acidification.
Sea water absorbs CO2 from
the atmosphere, which lowers
its Ph and results in higher acid content.
This reduces the concentration
of calcium carbonate
which makes it difficult for
species like oysters, clams
and corals to form shells or skeletons.
The only way to stop the
damage to our oceans is to
dramatically reduce
greenhouse gas emissions.
But even emissions stop tomorrow,
the gases currently in the
atmosphere would take
decades to dissipate.
(ominous music)
