- 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.
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