Transcript Document

Late Holocene and Present Sea Level Changes
Nils-Axel Mörner
President (1999-2003) of the INQUA Commission on
Sea Level Changes and Coastal Evolution
Leader of the Maldives Project (from 2000-2005 on);
an international research project among sea level specialists
Co-ordinator of the INTAS project on Geomagnetism and Climate (1998-2003)
Head of Paleogeophysics & Geodynamics at Stockholm University, Sweden
In the hot international sea level debate for 35 years
[email protected]
(www.pog.su.se/sea) www.pog.nu
Many variables control the stability of a shoreline
Sea Level Rose
for glacial eustatic reasons up to
about 5000 BP.
after that, global sea level has been
dominated by the redistribution
of ocean water masses
(and by that ocean stored energy)
In a feed-back coupling
in the interchange of angular momentum
(rate of rotation)
between the hydrosphere and solid Earth
by that driving the
ocean surface circulation
and its redistribution of
water masses & heat
(sea level & paleoclimate)
“Horizontal Eustasy”
Ocean Level Redistribution
I have argued for over 20 years
that sea level is changing
drastically
due to redistribution of water
masses
over the globe
and even claimed that this
is the dominating factor
for the last 5000 years
Satellite altimetry
records this differential
distribution of water massed
between 1993 and 2000
Despite the fact
that we do not
accept the proposed
on-going rise in sea level
Present-to-Future Sea Level Changes: methods used and values obtained
The combined observational records (in mm/year) for the last 300 years.
It shows variations – ups and downs – but no trend.
For year 2100, INQUA gives predictions in line with this record,
whilst the IPCC scenarios lie far above – way off – observational data
The new sea level curve of the Maldives; present level reached ~4000 BP, sea
level strongly oscillating for regional dynamic reasons, a drop in sea level
~1970, no rise in the last 30 years.
At ~1970
Sea Level fell some 20 cm
Causing erosion
with sand deposition
outward, downward
Leaving an old fossil shore and
an old overgrewing surface of
grey weathered corals.
The present shore
has remained stable
for ~30 years
Exploring some notorious sites
claimed to be in a ”flooding mode”
The Maldives: No rise but stability and fall ~1970
Tuvalu: No rising trend (tide gauge date from 1978)
Vanuatu: No rising trend (tide gauge data from 1993)
Venice: No acceleration (rather the opposite ~1970)
Eastern Mediterranean: Rise due to precipitation increase
Satellite altimetry is a new and important means of recording sea level.
The 1993-1999 record show NO rising trend.
Just a variability around a zero level (blue) + a major ENSO event (yellow).
This data set was presented on the TOPEX/POSEIDON web-page, in their publications,
and used by me in my paper in Global and Planetary Changes, vol. 40, 2004, p. 49-54
In 2003, a totally new record appeared on the web-page
Now there was a trend of 2.3 mm/year.
This trend, however, comes from selected tide gauge records
not satellite altimetry measurements
The ”flooding scenario” of IPCC does not concur with observational
sea level facts. Therefore, it must be called-off as a mistake.
Today, we favour a 2100 value of +5 cm +15 cm
There is no global sea level rise going on
that will flood islands and low-lying coasts in the near-future
It is high time to face available observational facts,
discard untenable model scenaria
and start discussing real threats in the real world
Today I launch a short book
entitled:
The Greatest Lie Ever Told
unfortunately I have to charge
15 Australian dollars for it