How much has the sea level risen so far?

Answer 1

Sea level rise is an increase in sea level. Multiple complex factors may influence this change.

Sea level has risen about 130 metres (400 feet) since the peak of the last ice age about 18,000 years ago. Most of the rise occurred before 6,000 years ago. From 3,000 years ago to the start of the 19th century sea level was almost constant, rising at 0.1 to 0.2 mm/yr.[1] Since 1900 the level has risen at 1 to 2 mm/yr; since 1992 satellite altimetry from TOPEX/Poseidon indicates a rate of rise about 3 mm/yr.[2] The IPCC TAR notes, however, "No significant acceleration in the rate of sea level rise during the 20th century has been detected." [2]

Sea level rise can be a product of global warming through two main processes: expansion of sea water as the oceans warm, and melting of ice over land. Global warming is predicted to cause significant rises in sea level over the course of the twenty-first century.


Local mean sea level (LMSL) is defined as the height of the sea with respect to a land benchmark, averaged over a period of time (such as a month or a year) long enough that fluctuations caused by waves and tides are smoothed out. One must adjust perceived changes in LMSL to account for vertical movements of the land, which can be of the same order (mm/yr) as sea level changes. Some land movements occur because of isostatic adjustment of the mantle to the melting of ice sheets at the end of the last ice age. The weight of the ice sheet depresses the underlying land, and when the ice melts away the land slowly rebounds. Atmospheric pressure, ocean currents and local ocean temperature changes also can affect LMSL.

“Eustatic” change (as opposed to local change) results in an alteration to the global sea levels, such as changes in the volume of water in the world oceans or changes in the volume of an ocean basin.


http://en.wikipedia.org/wiki/Sea_level_rise

Answer 2

According to wikipedia, the rate of global average sea level rise during the 20th century lies in the range 0.8 to 3.3 mm/yr, with an average rate of 1.8 mm/yr.

Answer 3

the IPCC "we're all going to die" report says if GW is left unchecked, the WORST case ....in one hundred years......


the WORST case


is 3 feet .


I've lived on a Caribbean island 30 years and can tell you sea level hasnt gone up.

Answer 4

From what base level? It has been much higher and much lower in the past.

Answer 5

Not much yet. We could be in for several feet...

http://www.stuffintheair.com/rising-ocean-levels.html

...and maybe not much at all.

Answer 6

No Idea.......but you'll soon find out when a wave comes knocking on your back door