Wednesday, September 15, 2010

"Experts predict more storm surges in the future"

The relation between storm surges and anthropogenic climate change is a permanent source of debate. Now experts say on the "Storm Surges Congress" in Hamburg that "through the effects of climate change and extensive human use of coastal areas, storm surge risks could rise worldwide." According to Prof. Nicholls from University of Southampton,  “(r)ecent predictions of the OECD assume that the risk of being hit by a so called one in hundred years flood will be multiplied for large harbor cities worldwide by the year 2070”.
While coasts in Germany should be well protected for the next two decades, according to Hans von Storch, this might change in the future: “Between 2070 and 2100 rises in maximum storm water levels in the range of three to eleven decimeters are conceivable along the entire German North Sea coast”.

Attention: I just DELETED a quote from Hans von Storch in Hamburger Abendblatt, Sept. 15th., which I had posted here originally. Hans let me know that this quote was not authorized (see comments). This is, I guess, how many discussions start: from a fake quote. I fully respect Hans' intervention, of course. It doesn't make any sense to start a discussion on basis of something that was never said. Or start it with a correction. Anyway, I am afraid that's the way many discussions go!


Hans von Storch said...

Werner, you should know your Hamburger Abendblatt better. I have not spoken to this journal (they do not let quotes authorize - therefore I do not speak to them); also this quote is not authorized. Maybe they picked something up in the press conference, but it is a miquote. Who would be surprised about it?

Werner Krauss said...

Unfortunately, I did not save the original quote in German (and I don't want to pay now; two hours ago, it was for free). It was (printed as) a direct quote with " ".

Hans von Storch said...

As I said, you should know your Hamburger Abendblatt. They "quote" without authorization.

Werner Krauss said...

Hans, I corrected my original entry. Of course, it doesn't make sense to discuss about something that you never have said. Instead, it would be interesting to discuss the fact that we probably often discuss on the basis of such 'invented' facts (quotes). Once printed, they will never be deleted. It's a gray zone, indeed.

Hans von Storch said...

The same newspaper had now a "menschlich gesehen" (about: seen as a human) about me without ever having met me.

Georg Hoffmann said...

Well "seen as a human", but from very far. Vive la press Hambourgois!
Mojib said once that surprisingly BILD is very correct with citations and stuff. Would you agree with that, Hans?

The citation with the hundred year flood is a bit strange. They say the risk beeing struck by a hundred year flood would be multiplied by the year 2070. I mean the risk beeing struck by a 100 year flood is, well, once in 100 years.

Hans von Storch said...

Yes, Bild-Zeitung is doing (comparably) good research; afterwards, there is some optimization for the public taste and entertainment.

Hans Erren said...

Aren't these new findings at odds with the Munich Re conference?

Could you please explain the mechanism how a decreasing Northpole-equator temperature difference can result in more storms, I would expect less.

"articles suggest that it is the cooler periods in Europe that were stormier, not the warmer ones"

Hans von Storch said...

Hans Erren/ Which new findings, and which Munich Re conference?

Hans Erren said...

Please correct me if i'm wrong but wasn't there a workshop in which you and pielke jr attended on storms by a reinsurance firm from which there were no conclusions on storm losses?

The new findings here are:
"Between 2070 and 2100 rises in maximum storm water levels in the range of three to eleven decimeters are conceivable along the entire German North Sea coast."

Can you please explain how this counter-intuitive result is obtained? Are we talking about an increase in subtropical hurricane remnants or an increase in arctic lows?
If it's the first: Isn't it so that surges on the dutch and german coast are caused by arctic depressions moving south?
Wouldn't hurricane remnants have a lowering effect on surges in the north sea because they move in from the west?
If it's the second: how can a decreasing Northpole-equator temperature gradient result in more arctic lows?

Please also see
No upward trend in normalised windstorm losses in Europe: 1970–2008

But I agree that even with constant storm stats, damage will increase, simply because property value on the coast is increasing.

Hans von Storch said...

Hans Erren / Most of the expected increase in storm surge height is due to a rise in mean sea level. In the German Bighht, we expect a minor increase in storm effects at the end of this century. (See Woth K., 2005: Projections of North Sea storm surge extremes in a warmer climate: How important are the RCM driving GCM and the chosen scenario? Geophys Res Lett: 32, L22708, doi: 10.1029/2005GL023762).

Our storm surges are almost entirely related to our "home storms", i.e. baroclinic storms along the polar front, travelling eastward, moving in from the west. They go with wind from mostly SW, W and NW directions.