Sea Level Trends - 1993 - 2012
There
are many questions surrounding climate change. One big question is
how the changing climate will affect the oceans. The sea level has
been steadily rising since 1900 at a rate of 1 to 2.5 millimeters per
year. In fact, since 1992 new methods of satellite altimetry using
the TOPEX/Poseidon satellite indicate a rate of rise of 3 millimeters
per year. The Fourth Assessment Report from the IPCC states that
"there is strong evidence that global sea level gradually rose
in the 20th century and is currently rising at an increased rate,
after a period of little change between AD 0 and AD 1900. Sea level
is projected to rise at an even greater rate in this century. "
- Fourth
Assessment Report on Sea Level Rise
Sea
level can rise by two different mechanisms with respect to climate
change. The first is the expansion of the sea water as the oceans
warm due to an increasing global temperature. The second mechanism is
the melting of ice over land, which then adds water to the ocean. The
IPCC Fourth Assessment Report predicts that total global-average sea
level rise from 1990 - 2100 will be 7 - 15 inches (177 - 381 mm) for
low emission scenarios and 10 - 23 inches (254 - 584 mm) for high
emission scenarios.
This
dataset for sea level trends comes from the University
of Colorado Sea Level Research Group and
highlights the sea level rise trends from 1993-2012. The trends have
been determined for only a nineteen-year period, and reflect the
impact of decadal scale climate variability on the regional
distribution of sea level rise. Additionally, local sea surface
height trends and variations are a result of many factors, including
(but not limited to) local rise of land height due to tectonic plate
activity or loss of heavy ice pressure, thermal expansion of warmer
water, and even local wind patterns. Therefore you should consider
these effects in interpreting the data.
Notable Features
- Areas of the Western Pacific are seeing up to 15mm per year of sea level rise compared with the Eastern Pacific where sea level has not seen a rise at all
- Global average sea level is rising about 2.5 mm/year and about 254 mm since 1880
To
watch the movie GO
HERE
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