Introductory, we may ask: Why would sea level change?
The ocean level may change for three main
• If the ocean volume would increase due to
• If the water column would expand due to
• If the water masses would move laterally
All these factors can be handles as to rates
and amplitudes (1, 2).
• During the deglacial period with maximum
climate stress and enormous masses of ice to melt, sea level rose at rates of
about 10 mm/year (1 m/cy). This value can be held as an ultimate frame for any
possible ice melting effect (2), rather would a realistic value for the present
to near-future be well below this value.
• The thermal expansion in the open oceans
can hardly exceed 10 cm (2). Towards the coasts, the effect rapidly decreases
with depth and becomes zero at the shore (because there is no water to expand
and there will be no flush inlands).
• The lateral water mass movements seem to
have dominated the local-to-regional sea level changes over the last 6000 or so
(1, 3, 4), and are well expressed in satellite altimetry maps (e.g. 5). The
group of sea level experts within the INQUA commission on Sea Level Changes and Coastal Evolution,
therefore, estimated the probably sea level change by year 2100 at +10 cm ±10
cm (6), later updated at +5 cm ±15 cm (7), which is significantly less than
proposed by IPCC (8), but rather in harmony with the mean of 159 global
tide-gauge records (9).
President Mohamed Nasheed of the Maldives
repeatedly claims: ”We are drowning, our nation will disappear,
we have to relocate the people”. In “open letters to the President” (10)
have pointed out that this violates observational facts in his own country.
Munch-Petersen (11) termed the President’s claims “marketing atoll dynamics as sea level rise”.
At about 1970, sea level fell by about 20 cm,
and has remained quite stable there after (i.e. for the last 30-40 years). We
have investigated several different shore environments (open coasts, rock-cut
platforms as in Fig. 2, sandy shores in erosion as well as in progradation,
lagoons, lakes, fens, etc.) with respect to stratigraphy, morphology, biology
and chronology (with 55 new C14-dates). Such an overwhelming mass and quality
of observational facts (Fig. 3C) must, of course, outdo idle talk (like what is
being claimed by IPCC and exaggerated by President Nasheed). Several scientific
reports have been published (13, 14, 15).
In 2009, I visited the Sunderban delta area
in Bangladesh and was able to observe clear evidence of strong coastal erosion
but no rise in sea level. The stratigraphy, morphology, vegetational evolution
and habitation record a minor sea level lowering at around 1960, followed by
40-50 years of stable sea level (Fig. 3B). Those sources of information are
superior to local tide-gauges in the Sunderban delta, which seem quite
unstable. The results are presented in a scientific report (16).
It seems significant that both the tide-gauge
of Mumbai and Visakhapatnam in India record a significant sea level drop in
1955-1962 (Fig. 3A) followed by 50 years of stable sea level (15,16).
2c. Minicoy in the Lakshadweep
I have previously tried to assess the global
trend (7, 9). Another way is to consider the Earth’s rate of rotation (1, 4).
In case of a global sea level rise, the Earth must slow down (following the law
of conservation of angular momentum). After 1972, the Earth rotation has
speeded up, however (Fig. 4). This is a strong argument against a global sea
In conclusion, there is no sea level rise
going on in the Indian Ocean (Fig. 2). All talk about an alarming ongoing rise
in sea level is nothing but an illusion to be abandoned the sooner the better,
because it steals the limelight from
real problems in the real world (17).
Session 3 on “The Illusive Sea Level Threat in the Indian Ocean” of ICAMG7 in
Goa (October 11) and the conference on “Climate
Change: Shifting science and changing policy” at the University of
Mumbai (October 14) both included papers on sea level changes in the Indian
Ocean (N.-A. Mörner, N.F. Munch-Petersen and A.S. Gaur) and papers on
solar-terrestrial interaction and monsoonal variability (W. Soon, R. Agnihorti,
K.Selvaraj, M. Khandekar, plus others in Mumbai). Taken together those
contributions allow the following final conclusions, which ended Session 3 in
1 Mörner, N.-A., 1996. Sea level variability.
Zeitschrift für Geomorphologie N.F., 102, p. 223-232.
2 Mörner, N.-A., 2011. Setting the frames of
expected future sea level changes by exploring past geological sea level
records. In "Evidence-based Climate Science", D.J.
Easterbrook, Ed., Chapter 6, p. 185-196, Elsevier.
3 Mörner, N.-A., 1995. Earth rotation, ocean
circulation and paleoclimate. GeoJournal, 37.4, p. 419-430.
4 Mörner, N.-A., 1990. The Earth’s
differential rotation; Hydrospheric changes. In: Variations in Earth
Rotation, D.D McCarthy & W.E. Carter, Ed, AGU, Geophysical Monograph
59, p. 27-32.
5 Nicholls, R.J. & Casenave, A., 2010.
Sea-level rise and its impact on coastal zones. Science, 328, p. 1517-1520.
6 INQUA, 2000. The Commission on “Sea Level
Changes and Coastal Evolution”, www.pog.se/sea (2000), www.pog.nu (2005).
7 Mörner, N.-A., 2004. Estimating future sea
level changes. Global Planetary Change, 40, p. 49-54.
8 IPCC, 2001 & 2007. Climate Change.
Cambridge Univ. Press, Oxford.
9 Mörner, N.-A., 2010. No alarming sea level
rise. A great sea level humbug revealed. 21st Century Science &
Technology, Winter 2010/2011 issue, p. 7-17.
10 Mörner, N.-A., 2009. Open letter to President
Mohamed Nasheed of the Maldives. New Concepts in Global Tectonics Newsletter,
11 Munch-Petersen, N.F., 2001. Marketing
atoll dynamics as sea level rise in the Maldives. Conference on Climate Change:
Shifting science and changing policy, University of Mumbai, Abstracts, p. 9.
12 Mörner, N.-A., 2010. Some problems in the
reconstruction of mean sea level and its changes with time. Quaternary
International, 221, p. 3-8.
13 Mörner, N.-A., Tooley, M. & Possnert,
G., 2004. New perspectives for the future of the Maldives. Global and
Planetary Change, 40, p.177-182.
14 Mörner, N.-A., 2007. Sea level changes and
tsunamis, environmental stress and migration overseas. Internationales
Asienforum, 38, p.353-374.
15 Mörner, N.-A., 2011. The Maldives: a measure
of sea level changes and sea level ethics. In "Evidence-based Climate
Science", D.J. Easterbrook, Ed., Chapter 7, p. 197-209, Elsevier.
16 Mörner, N.-A., 2010. Sea level changes in
Bangladesh. New observational facts. Energy & Environment, 213, p. 249-263.
17 Mörner, N.-A., 2011. Sea level changes in
the Indian Ocean: Observational facts. 7th ICAMG, NIO, Goa, Abstracts, p. 53,
and Conference on Climate Change: Shifting science and changing policy,
University of Mumbai, Abstracts, p. 8-9.
Post a Comment