A voluminous article [1] about the anthropic influence on the climate and its consequences on the rise of the level of the seas has just been published by a team led by the famous Jim Hansen.

According to paleo-climatic information and by means of models and scenarios developed to that purpose it is asserted that an important loss of glacial mass of Antarctica could take place which would have consequence that the global sea level could rise by 5 to 9 meters.

The way with which this article was published and its particular promotion by contracting a communication company raises many debates and even arouses more doubt, or indifference, than more alarmist responses [2]. Grasp all, lose all!

It is neither my competence nor have I available time to fully analyze this article. However it is straightaway shocking by its use of not validated models and by its approximations as for a relation between the melting of Antarctica and the emissions of so-called greenhouse gases. To say that an event is possible does not make it probable, nothing is discussed in the paper about the lack of probability for the current century or the next millennium.

It called my attention that, when speaking about sea level, its current state should be presented. This was actually made:

Figure 1       Sea level trend as presented in the paper

Why then is this graph beginning in 1900 and is not covering all available data (there are so few)?

Figure 2  Global mean sea level
Source:   John A. Church, Neil J. White, “Sea-Level Rise from the Late 19th to the Early 21st Century”, Surveys in Geophysics, Volume 32, Issue 4-5 , pp 585-602
and Jevrejeva, S., J. C. Moore, A. Grinsted, and P. L. Woodworth, “Recent global sea level acceleration started over 200 years ago?” (2008), Geophys. Res. Lett., 35
Satellites : Combined TOPEX/Poseidon, Jason-1 and Jason-2/OSTM

Since the 18^th century the rate of rise of the global sea level was of the same order of magnitude as what it currently is. This rate is oscillating with irregular periods, as seen on the next graph:

Figure 6 Rate of rise of global mean sea level

No acceleration can be observed. The coefficient of correlation R² for the Jevrejeva series is 0.0555, which indicates that nothing is statistically significant.

Let us remind that at the speed of ice sheet losses over the last 25 years, Greenland could have melted all its icecap in 10’000 years and Antarctica in 380’000 years. We feel the urgency!
On average this loss corresponds to 0.9 mm per year. The rest of the rise of the sea level must be thus due to other phenomena, temperature and tectonic movements.

Other important point: before 2100 it is said that the level could rise from 5 to 9 meters. It would mean that the rise rate would pass from of 0.9 mm per year to at least 65-100 mm/a, and that would have to begin at once, tomorrow morning. But in order to become true this ice must necessarily have been molten. How can we imagine the atmosphere causing such a heat transfer? The number of days when the temperature on the surface of Antarctica is superior to 0 °C should increase spectacularly. The tiny temperature anomalies observed or even imagined at 2 °C would not suffice. The paper of Hansen discusses no aspect of this necessary heat transfer.

It is quite remarkable to notice that in this article the word “experiment” is used to speak about the use of models – well parametrized for the desired effect- to simulate future scenarios.
When I calculate a hypothesis I perform an experience; Feynman has to turn around in his grave!
With this “newspeak” the experimental researchers are soon going to have to call their work “physical simulations”!

If such defects and lack of plausibility are noticed on crucial points in an article which is claimed to be fundamental, what should we think about the rest of it?

One more alarmism, one!

As this paper is opened to comments I submitted one, we shall see what happens:

http://www.atmos-chem-phys-discuss.net/15/2005 9/2015/acpd-15-20059-2015-discussion.html.

[1] Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 °C global warming is highly dangerous.
J. Hansen et al.
Atmos. Chem. Phys. Discuss., 15, 20059–20179, 2015
www.atmos-chem-phys-discuss.net/15/20059/2015/
doi:10.5194/acpd-15-20059-2015

[2] Look at an intelligent discussion on J. Curry’s blog: http://judithcurry.com/2015/07/26/hansens-backfire/

Merci de partager et de diffuser cet article !